Substituted cyclopentyl- and cyclohexyl-derivatives useful for perfumery

Abstract

The present invention refers to substituted cyclopentyl- and cyclohexyl-derivatives of formula (I) ##STR00001## wherein n, R.sup.1, R.sup.2, R.sup.3, R.sup.4 and X have the same meaning as given in the description. The invention further refers to fragrance compositions and fragranced articles comprising them.

Claims

1. A method comprising using as a fragrance alone or combining with a base material in a fragranced article, a compound of formula (I) ##STR00005## wherein n is 1 or 2; R.sup.1 and R.sup.2 are independently selected from the group consisting of hydrogen, methyl, ethyl, and C.sub.3-C.sub.5 alkyl; or R.sup.1 and R.sup.2 form together with the carbon atom to which they are attached C.sub.3-C.sub.6 cycloalkyl; or R.sup.1 and R.sup.2 form together methylidene; R.sup.3 is selected from hydrogen, and C.sub.1-C.sub.3 alkyl; R.sup.4 is selected from hydrogen, and C.sub.1-C.sub.3 alkyl; and X is CN; or X is C(O)OR.sup.5, wherein R.sup.5 is selected from the group consisting of methyl, ethyl, C.sub.3-C.sub.5 alkyl, vinyl and C.sub.3-C.sub.5 alkenyl; with the proviso that a) at least two of the residues R.sup.1, R.sup.2 and R.sup.3 are not hydrogen; b) when R.sup.3 is hydrogen, R.sup.4 is selected from C.sub.1-C.sub.3 alkyl; c) when X is CN, and R.sup.1, R.sup.2 and R.sup.3 are methyl, then R.sup.4 is not hydrogen.

2. The method according to claim 1 wherein the compound of formula (I) is selected from the group consisting of ethyl 2-(1,2,2-trimethylcyclopentyl)propanoate, methyl 2-(1,2,2-trimethylcyclopentyl)acetate, methyl 2-(1,2,2-trimethylcyclopentyl)propanoate, propyl 2-(1,2,2-trimethylcyclopentyl)propanoate, isopropyl 2-(1,2,2-trimethylcyclopentyl)propanoate, but-3-en-1-yl 2-(1,2,2-trimethylcyclopentyl)propanoate, isobutyl 2-(1,2,2-trimethylcyclopentyl)propanoate, allyl 2-(1,2,2-trimethylcyclopentyl)propanoate, methyl 2-(1-methylspiro[4.4]nonan-1-yl)acetate, methyl 2-(1-methylspiro[4.4]nonan-1-yl)propanoate, ethyl 2-(1-methylspiro[4.4]nonan-1-yl)acetate, ethyl 2-(1-methylspiro[4.4]nonan-1-yl)propanoate, ethyl 2-(1-methyl-2-methylenecyclopentyl)propanoate, ethyl 2-(4-methylspiro[2.4]heptan-4-yl)propanoate, ethyl 2-(2-ethyl-1,2-dimethylcyclopentyl)acetate, ethyl 2-(2-ethyl-1,2-dimethylcyclopentyl)propanoate, ethyl 2-(1,2-dimethyl-2-propylcyclopentyl)propanoate, ethyl 2-(1,2,2-trimethylcyclopentyl)acetate, ethyl 2-(1,2,2-trimethylcyclopentyl)butanoate, ethyl 2-(1,2,2-trimethylcyclopentyl)pentanoate, ethyl 2-(1-ethyl-2,2-dimethylcyclopentyl)propanoate, ethyl 2-(1,2-dimethylcyclopentyl)propanoate, 2-(1,2,2-trimethylcyclopentyl)propanenitrile, 2-(2-ethyl-1,2-dimethylcyclopentyl)acetonitrile, ethyl 2-(2,2-dimethylcyclopentyl)propanoate, ethyl 2-(2,2-dimethylcyclohexyl)propanoate, ethyl 2-(1,2,2-trimethylcyclohexyl)acetate, and ethyl 2-(1,2,2-trimethylcyclohexyl)propanoate.

3. A fragranced article comprising as odorant a compound of formula (I), ##STR00006## wherein n is 1 or 2; R.sup.1 and R.sup.2 are independently selected from the group consisting of hydrogen, methyl, ethyl, and C.sub.3-C.sub.5 alkyl; or R.sup.1 and R.sup.2 form together with the carbon atom to which they are attached C.sub.3-C.sub.6 cycloalkyl; or R.sup.1 and R.sup.2 form together methylidene; R.sup.3 is selected from hydrogen, and C.sub.1-C.sub.3 alkyl; R.sup.4 is selected from hydrogen, and C.sub.1-C.sub.3 alkyl; and X is CN; or X is C(O)OR.sup.5, wherein R.sup.5 is selected from the group consisting of methyl, ethyl, C.sub.3-C.sub.5 alkyl, vinyl and C.sub.3-C.sub.5 alkenyl; with the proviso that a) at least two of the residues R.sup.1, R.sup.2 and R.sup.3 are not hydrogen; b) when R.sup.3 is hydrogen, R.sup.4 is selected from C.sub.1-C.sub.3 alkyl; c) when X is CN, and R.sup.1, R.sup.2 and R.sup.3 are methyl, then R.sup.4 is not hydrogen; or a mixture thereof, and a consumer product base.

4. The fragranced article according to claim 3 wherein the consumer product base is selected from the group consisting of fine perfumery, household products, laundry products, body care products, cosmetic and air care products.

5. A method of improving, enhancing or modifying a consumer product base by means of addition thereto of an olfactory acceptable amount of a compound of formula (I), ##STR00007## wherein n is 1 or 2; R.sup.1 and R.sup.2 are independently selected from the group consisting of hydrogen, methyl, ethyl, and C.sub.3-C.sub.5 alkyl; or R.sup.1 and R.sup.2 form together with the carbon atom to which they are attached C.sub.3-C.sub.6 cycloalkyl; or R.sup.1 and R.sup.2 form together methylidene; R.sup.3 is selected from hydrogen, and C.sub.1-C.sub.3 alkyl; R.sup.4 is selected from hydrogen, and C.sub.1-C.sub.3 alkyl; and X is CN; or X is C(O)OR.sup.5, wherein R.sup.5 is selected from the group consisting of methyl, ethyl, C.sub.3-C.sub.5 alkyl, vinyl and C.sub.3-C.sub.5 alkenyl; with the proviso that a) at least two of the residues R.sup.1, R.sup.2 and R.sup.3 are not hydrogen; b) when R.sup.3 is hydrogen, R.sup.4 is selected from C.sub.1-C.sub.3 alkyl; c) when X is CN, and R.sup.1, R.sup.2 and R.sup.3 are methyl, then R.sup.4 is not hydrogen.

6. A compound of formula (I), ##STR00008## wherein n is 1 or 2; R.sup.1 and R.sup.2 are independently selected from the group consisting of hydrogen, methyl, ethyl, and C.sub.3-C.sub.5 alkyl; or R.sup.1 and R.sup.2 form together with the carbon atom to which they are attached C.sub.3-C.sub.6 cycloalkyl; R.sup.3 is selected from hydrogen, and C.sub.1-C.sub.3 alkyl; R.sup.4 is selected from hydrogen, and C.sub.1-C.sub.3 alkyl; and X is CN; or X is C(O)OR.sup.5, wherein R.sup.5 is selected from the group consisting of methyl, ethyl, C.sub.3-C.sub.5 alkyl, vinyl and C.sub.3-C.sub.5 alkenyl; with the proviso that a) at least two of the residues R.sup.1, R.sup.2 and R.sup.3 are not hydrogen; b) when R.sup.3 is hydrogen, R.sup.4 is selected from C.sub.1-C.sub.3 alkyl; c) when X is CN, and R.sup.1, R.sup.2 and R.sup.3 are methyl, then R.sup.4 is not hydrogen; d) when n is 2; R.sup.1 and R.sup.2 are not hydrogen.

7. The compound according to claim 6 selected from the group consisting of ethyl 2-(1,2,2-trimethylcyclopentyl)propanoate, methyl 2-(1,2,2-trimethylcyclopentyl)acetate, methyl 2-(1,2,2-trimethylcyclopentyl)propanoate, propyl 2-(1,2,2-trimethylcyclopentyl)propanoate, isopropyl 2-(1,2,2-trimethylcyclopentyl)propanoate, but-3-en-1-yl 2-(1,2,2-trimethylcyclopentyl)propanoate, isobutyl 2-(1,2,2-trimethylcyclopentyl)propanoate, allyl 2-(1,2,2-trimethylcyclopentyl)propanoate, methyl 2-(1-methylspiro[4.4]nonan-1-yl)acetate, methyl 2-(1-methylspiro[4.4]nonan-1-yl)propanoate, ethyl 2-(1-methylspiro[4.4]nonan-1-yl)acetate, ethyl 2-(1-methylspiro[4.4]nonan-1-yl)propanoate, ethyl 2-(1-methyl-2-methylenecyclopentyl)propanoate, ethyl 2-(4-methylspiro[2.4]heptan-4-yl)propanoate, ethyl 2-(2-ethyl-1,2-dimethylcyclopentyl)acetate, ethyl 2-(2-ethyl-1,2-dimethylcyclopentyl)propanoate, ethyl 2-(1,2-dimethyl-2-propylcyclopentyl)propanoate, ethyl 2-(1,2,2-trimethylcyclopentyl)acetate, ethyl 2-(1,2,2-trimethylcyclopentyl)butanoate, ethyl 2-(1,2,2-trimethylcyclopentyl)pentanoate, ethyl 2-(1-ethyl-2,2-dimethylcyclopentyl)propanoate, ethyl 2-(1,2-dimethylcyclopentyl)propanoate, 2-(1,2,2-trimethylcyclopentyl)propanenitrile, 2-(2-ethyl-1,2-dimethylcyclopentyl)acetonitrile, ethyl 2-(2,2-dimethylcyclopentyl)propanoate, ethyl 2-(2,2-dimethylcyclohexyl)propanoate, ethyl 2-(1,2,2-trimethylcyclohexyl)acetate, and ethyl 2-(1,2,2-trimethylcyclohexyl)propanoate.

Description

EXAMPLE 1: SYNTHESIS OF ETHYL 2-(1,2,2-TRIMETHYLCYCLOPENTYL)PROPANOATE

a) Synthesis of ethyl 2,3,7-trimethylocta-2,6-dienoate

(1) Ethyl 2-(diethoxyphosphoryl)propanoate (1133 g, 4.76 mol) was added to a suspension of potassium t-butylat (450 g, 4.04 mol) in toluene (2.8 l) at 25-35 C. After the yellow suspension was stirred at 25 C. for 30 min, 6-methylhept-5-en-2-one (300 g, 2.38 mol) in toluene (0.2 L) was added at 5-15 C., and the mixture was stirred at 25 C. for 20 h. After addition of 2M aq. HCl-solution, the phases were separated and the aq. layer was extracted with hexane. The org. phases were washed with H.sub.2O and brine, dried (MgSO.sub.4), filtered and the filtrate was concentrated. The residue was re-dissolved in hexane and the org. phase was washed with 2M aq. HCl (2), 15% aq. Na.sub.2CO.sub.3 and brine, dried (MgSO.sub.4), filtered and the filtrate was concentrated. The crude product was purified by distillation (b.p. 75 C., 0.13 mbar) to yield 410 g (82%) of ethyl 2,3,7-trimethylocta-2,6-dienoate (mixture of E/Z-isomers; ratio 1.2:1) as a colorless oil.

(2) .sup.1H NMR (CDCl.sub.3, 400 MHz); mixture of E/Z-isomers: =5.16-5.10 (m, 2H), 4.19 (q, J=7.2 Hz, 2H), 4.18 (q, J=7.2 Hz, 2H), 2.37-2.33 (m, 2H), 2.17-2.07 (m, 6H), 1.99 (q, J=1.5 Hz, 3H), 1.87 (q, J=1.5 Hz, 3H), 1.84 (q, J=1.0 Hz, 3H), 1.79 (q, J=1.0 Hz, 3H), 1.69 (br. q, J=1.0 Hz, 3H), 1.68 (br. q, J=1.2 Hz, 3H), 1.61 (br. s, 6H), 1.30 (t, J=7.1 Hz, 3H), 1.29 (t, J=7.1 Hz, 3H) ppm.

(3) .sup.13C-NMR (CDCl.sub.3, 100 MHz); mixture of E/Z-isomers: =169.9 (s), 169.7 (s), 145.9 (s), 145.5 (s), 132.2 (s), 131.7 (s), 123.9 (d), 123.5 (d), 123.0 (s), 122.8 (s), 59.9 (2t), 36.4 (t), 36.1 (t), 27.1 (t), 25.9 (t), 25.6 (2q), 20.9 (q), 20.2 (q), 17.5 (q), 17.5 (q), 15.8 (q), 15.2 (q), 14.2 (q), 14.2 (q) ppm.

(4) MS (EI, tR=7.12 min); major isomer: 210 (1, [M].sup.+.), 165 (13, [M].sup.+.-EtO.sup..), 142 (18), 137 (18), 96 (36), 69 (100), 67 (15), 53 (13), 43 (10), 41 (58), 39 (9), 29 (8).

(5) MS (EI, tR=6.92 min); minor isomer: 210 (2, [M].sup.+.), 165 (10, [M].sup.+.-EtO.sup..), 142 (25), 137 (27), 97 (12), 96 (53), 69 (100), 67 (21), 53 (17), 43 (16), 41 (71), 39 (12), 29 (10).

b) Synthesis of ethyl 2-(1,2,2-trimethylcyclopentyl)propanoate

(6) Polymethylhydrosiloxane (25 g) was added to a suspension of ethyl 2,3,7-trimethylocta-2,6-dienoate (52.6 g, 250 mmol) and Fe(acac).sub.3 (26.5 g, 75 mmol) in ethanol/ethylene glycol (450 ml; ratio 5:1) at 25 C. The mixture was stirred at 60 C. for 3 h, cooled to 25 C., filtered through a pad of Celite and washed with hexane. After addition of H.sub.2O, the phases were separated and the aq. layer was extracted with hexane. The org. phases were washed with H.sub.2O, dried (MgSO.sub.4), filtered and the filtrate was concentrated. The residue was filtered through a pad of SiO.sub.2 and washed with hexane/EtOAc (19:1). The filtrate was concentrated to yield 51.6 g (94%, purity 97%) of ethyl 2-(1,2,2-trimethylcyclopentyl)propanoate as a mixture of two diastereomers (ratio 2.2:1) as a colorless oil. An olfactive pure sample was obtained by distillation or purification by flash chromatography on SiO.sub.2 (hexane/EtOAc 99:1.fwdarw.98:2).

(7) .sup.1H NMR (CDCl.sub.3, 400 MHz); mixture of two diastereomers: =4.15-4.03 (m, 4H), 2.62 (q, J=7.1 Hz, 1H), 2.55 (q, J=7.1 Hz, 1H), 1.93-1.84 (m, 1H), 1.79-1.50 (m, 8H), 1.44-1.32 (m, 3H), 1.27 (t, J=7.1 Hz, 3H), 1.25 (t, J=7.1 Hz, 3H), 1.14 (d, J=7.1 Hz, 3H), 1.12 (d, J=7.1 Hz, 3H), 1.02 (s, 3H), 1.01 (s, 3H), 1.00 (s, 3H), 0.96 (d, J=0.7 Hz, 3H), 0.95 (s, 3H), 0.81 (s, 3H) ppm.

(8) .sup.13C-NMR (CDCl.sub.3, 100 MHz); mixture of two diastereomers: =176.3 (s), 176.2 (s), 59.7 (t), 59.7 (t), 48.2 (s), 46.6 (s), 45.2 (d), 44.4 (s), 44.3 (d), 43.9 (s), 41.4 (t), 41.4 (t), 38.7 (t), 38.6 (t), 25.3 (q), 25.2 (q), 24.6 (q), 23.1 (q), 19.2 (t), 18.4 (t), 16.8 (q), 16.7 (q), 15.1 (q), 14.3 (q), 14.1 (q), 13.2 (q) ppm.

(9) MS (EI, tR=6.88 min); major isomer: 212 (1, [M].sup.+.), 197 (4), 166 (35, [M].sup.+.-EtOH), 141 (10), 139 (11), 127 (13), 111 (26), 109 (19), 102 (100), 95 (30), 83 (35), 69 (64), 57 (21), 55 (50), 43 (12), 41 (37), 29 (19).

(10) MS (EI, tR=6.79 min); minor isomer: 212 (1, [M].sup.+.), 197 (5), 169 (27), 166 (44, [M].sup.+. EtOH), 141 (19), 139 (12), 127 (13), 124 (13), 123 (12), 111 (26), 109 (22), 102 (100), 95 (38), 83 (35), 69 (69), 57 (23), 55 (57), 43 (15), 41 (44), 29 (23).

(11) Odor description: fruity agrestic, strawberry, apple, sparkling with a champagne feeling, slightly floral rosy.

EXAMPLE 2: SYNTHESIS OF METHYL 2-(1,2,2-TRIMETHYLCYCLOPENTYL)PROPANOATE

a) Synthesis of methyl 2-(1,2,2-trimethylcyclopentyl)acetate

(12) Phenylsilane (4.6 ml, 37.5 mmol) was added to a suspension of methyl 3,7-dimethylocta-2,6-dienoate (4.9 ml, 25.0 mmol) and Fe(acac).sub.3 (2.65 g, 7.50 mmol) in ethanol/ethylene glycol (90 ml; ratio 5:1) at 25 C. The mixture was stirred at 60 C. for 1 h, cooled to 25 C., filtered through a pad of Celite and washed with hexane. After addition of H.sub.2O, the phases were separated and the aq. layer was extracted with hexane. The org. phases were washed with brine, dried (MgSO.sub.4), filtered and the filtrate was concentrated. The residue was purified by flash chromatography on SiO.sub.2 (hexane/EtOAc 98:2.fwdarw.95:5) to yield 4.06 g (80%, purity 91%) of methyl 2-(1,2,2-trimethylcyclopentyl)acetate as a colorless oil.

(13) .sup.1H NMR (CDCl.sub.3, 400 MHz): =3.65 (s, 3H), 2.27-2.19 (m, 2H), 1.89-1.80 (m, 1H), 1.66-1.57 (m, 4H), 1.51-1.45 (m, 1H), 0.93 (s, 3H), 0.88 (s, 3H), 0.85 (s, 3H) ppm.

(14) .sup.13C-NMR (CDCl.sub.3, 100 MHz): =173.9 (s), 51.1 (q), 45.2 (s), 43.9 (s), 41.4 (t), 39.0 (t), 36.8 (t), 24.5 (q), 23.6 (q), 21.1 (q), 19.4 (t) ppm.

(15) MS (EI): 184 (1, [M].sup.+.), 169 (7), 153 (31), 152 (100, [M].sup.+.-MeOH), 141 (32), 111 (58), 110 (95), 109 (42), 96 (30), 95 (89), 94 (35), 82 (32), 69 (65), 59 (23), 55 (67), 41 (66), 29 (19).

(16) Odor description: green fruity woody.

b) Synthesis of methyl 2-(1,2,2-trimethylcyclopentyl)propanoate

(17) Methyl 2-(1,2,2-trimethylcyclopentyl)acetate (1.13 g, 6.13 mmol) in THF (3 ml) was added to a solution of LDA (freshly prepared from BuLi (3.8 ml, 6.13 mmol) and diisopropylamine (0.9 ml, 6.13 mmol)) in THF (6 ml) at 78 C. The mixture was stirred at 78 C. for 1 h before MeI (0.4 ml, 6.75 mmol) in THF (3 ml) was added at 78 C. The mixture was stirred at 78 C. for 1.5 h and at 25 C. for 2 h. After addition of sat. aq. NH.sub.4Cl-solution, the phases were separated and the aq. layer was extracted with MTBE. The org. phases were dried (MgSO.sub.4), filtered and the filtrate was concentrated. The residue was purified by flash chromatography on SiO.sub.2 (hexane/EtOAc 98:2) to yield 0.67 g (51%, purity 93%) of methyl 2-(1,2,2-trimethylcyclopentyl)propanoate as a mixture of two diastereomers (ratio 2.5:1) as a light yellow oil.

(18) .sup.1H NMR (CDCl.sub.3, 400 MHz); mixture of two diastereomers: =3.65 (s, 3H), 3.63 (s, 3H), 2.65 (q, J=7.1 Hz, 1H), 2.58 (q, J=7.1 Hz, 1H), 1.89-1.30 (m, 12H), 1.14 (d, J=7.1 Hz, 3H), 1.12 (d, J=7.1 Hz, 3H), 1.01 (br. s, 6H), 0.99 (s, 3H), 0.96 (d, J=1.0 Hz, 3H), 0.95 (s, 3H), 0.79 (s, 3H) ppm.

(19) .sup.13C-NMR (CDCl.sub.3, 100 MHz); mixture of two diastereomers: =176.8 (s), 176.7 (s), 51.0 (q), 50.9 (q), 48.2 (s), 46.6 (s), 45.1 (d), 44.4 (s), 44.1 (d), 43.9 (s), 41.4 (t), 41.3 (t), 38.7 (t), 38.6 (t), 25.3 (q), 25.2 (q), 24.6 (q), 23.0 (q), 19.2 (t), 18.4 (t), 16.8 (q), 16.6 (q), 15.1 (q), 13.2 (q) ppm.

(20) MS (EI, tR=6.29 min); major isomer: 198 (1, [M].sup.+.), 183 (4), 166 (37, [M].sup.+.-MeOH), 155 (39), 139 (6), 111 (42), 95 (50), 88 (100), 83 (40), 69 (87), 67 (27), 59 (27), 55 (90), 41 (75), 29 (18).

(21) MS (EI, tR=6.38 min); minor isomer: 198 (1, [M].sup.+.), 183 (4), 166 (32, [M].sup.+.-MeOH), 139 (6), 127 (13), 111 (42), 102 (53), 95 (40), 88 (100), 83 (42), 69 (84), 59 (26), 57 (33), 55 (86), 43 (11), 41 (75), 29 (18).

(22) Odor description: fruity agrestic, strawberry, raspberry, bornyl fruity minty.

EXAMPLE 3

a) Synthesis of 2-(1,2,2-trimethylcyclopentyl)propanoic acid

(23) Sodium hydroxide (11.0 g, 274 mmol) was added to ethyl 2-(1,2,2-trimethylcyclopentyl)-propanoate (Example 1) (4.17 g, 19.6 mmol) in MeOH (30 ml) and H.sub.2O (10 ml) at 25 C. and the reaction mixture was stirred at reflux for 20 h. After addition of 2M aq. NaOH-solution, the aq. layer was extracted with MTBE (2). The aq. phase was acidified with conc. HCl until a pH of 1 was reached and extracted again with MTBE (2). The org. phases were dried (MgSO.sub.4), filtered and the filtrate was concentrated to yield 3.13 g (86%) of 2-(1,2,2-trimethylcyclopentyl)propanoic acid as a white solid.

b) Synthesis of propyl 2-(1,2,2-trimethylcyclopentyl)propanoate

(24) Sulfuric acid (0.5 ml, 9.23 mmol) was added to 2-(1,2,2-trimethylcyclopentyl)propanoic acid (1.70 g, 9.23 mmol) in propan-1-ol (20.8 ml, 276 mmol) at 25 C. and the reaction mixture was stirred at reflux for 24 h. After addition of H.sub.2O, the aq. layer was extracted with MTBE (2). The org. phases were washed with 50% aq. NaOH-solution (3) and brine, dried (MgSO.sub.4), filtered and the filtrate was concentrated. The residue was purified by flash chromatography on SiO.sub.2 (hexane/EtOAc 95:5) to yield 0.87 g (39%, purity 94%) of propyl 2-(1,2,2-trimethylcyclopentyl)propanoate as a mixture of two diastereomers (ratio 22:1) as a colorless oil.

(25) .sup.13C-NMR (CDCl.sub.3, 100 MHz); major isomer: =176.4 (s), 65.5 (t), 46.5 (s), 45.3 (d), 44.4 (s), 41.4 (t), 38.8 (t), 25.3 (2q), 22.0 (t), 19.2 (t), 16.9 (q), 13.3 (q), 10.6 (q) ppm.

(26) MS (EI); major isomer: 226 (1, [M].sup.+.), 211 (2), 167 (18), 166 (41), 139 (17), 116 (78), 111 (36), 109 (30), 95 (41), 83 (49), 74 (53), 69 (100), 57 (50), 55 (92), 43 (63), 41 (85), 29 (13), 27 (15).

(27) Odor description: fruity sweet agrestic, slightly woody.

c) Synthesis of isopropyl 2-(1,2,2-trimethylcyclopentyl)propanoate

(28) According to Example 3b, starting from 2-(1,2,2-trimethylcyclopentyl)propanoic acid (1.34 g, 7.27 mmol) and propan-2-ol (16.7 ml, 218 mmol), 0.80 g (46%, purity 94%) of isopropyl 2-(1,2,2-trimethylcyclopentyl)propanoate was obtained after purification by FC on SiO.sub.2 (hexane/EtOAc 95:5) as a mixture of two diastereomers (ratio 6:1) as a colorless oil.

(29) .sup.13C-NMR (CDCl.sub.3, 100 MHz); major isomer: =175.8 (s), 66.9 (d), 46.6 (s), 45.4 (d), 44.5 (s), 41.4 (t), 38.7 (t), 25.3 (q), 25.2 (q), 21.9 (q), 21.8 (q), 19.2 (t), 16.9 (q), 13.2 (q) ppm.

(30) MS (EI); major isomer: 226 (1, [M].sup.+.), 211 (1), 184 (5), 183 (6), 166 (42), 139 (16), 116 (37), 111 (64), 109 (37), 95 (36), 83 (43), 74 (41), 69 (100), 57 (52), 55 (77), 43 (67), 41 (64), 29 (8), 27 (8).

(31) Odor description: fruity raspberry.

d) Synthesis of but-3-en-1-yl 2-(1,2,2-trimethylcyclopentyl)propanoate

(32) According to Example 3b, starting from 2-(1,2,2-trimethylcyclopentyl)propanoic acid (1.00 g, 5.43 mmol) and but-3-en-1-ol (7.0 ml, 81 mmol), 0.27 g (20%, purity 96%) of but-3-en-1-yl 2-(1,2,2-trimethylcyclopentyl)propanoate was obtained after purification by FC on SiO.sub.2 (hexane/EtOAc 98:2) as a mixture of two diastereomers (ratio>30:1) as a colorless oil.

(33) .sup.13C-NMR (CDCl.sub.3, 100 MHz); major isomer: =176.3 (s), 134.2 (d), 117.1 (t), 63.0 (t), 46.5 (s), 45.3 (d), 44.5 (s), 41.4 (t), 38.8 (t), 33.1 (t), 25.3 (q), 25.3 (q), 19.2 (t), 16.9 (q), 13.3 (q) ppm.

(34) MS (EI); major isomer: 238 (1, [M].sup.+.), 223 (1), 167 (8), 166 (18), 139 (6), 124 (5), 111 (12), 109 (19), 95 (16), 86 (30), 83 (16), 69 (41), 57 (20), 55 (100), 41 (27), 29 (8).

(35) Odor description: fruity apple.

e) Synthesis of isobutyl 2-(1,2,2-trimethylcyclopentyl)propanoate

(36) According to Example 3b, starting from 2-(1,2,2-trimethylcyclopentyl)propanoic acid (0.76 g, 4.12 mmol) and 2-methylpropan-1-ol (11.5 ml, 124 mmol), 0.82 g (77%, purity 93%) of isobutyl 2-(1,2,2-trimethylcyclopentyl)propanoate was obtained after purification by distillation (Kugelrohr apparatus, 90 C., 0.10 torr) as a mixture of two diastereomers (ratio 10:1) as a colorless oil.

(37) .sup.13C-NMR (CDCl.sub.3, 100 MHz); major isomer: =176.4 (s), 70.2 (t), 46.5 (s), 45.5 (d), 44.5 (s), 41.4 (t), 38.8 (t), 27.7 (d), 25.3 (q), 25.3 (q), 19.3 (q), 19.3 (q), 19.2 (t), 16.9 (q), 13.3 (q) ppm

(38) MS (EI); major isomer: 240 (1, [M].sup.+.), 225 (1), 184 (2), 167 (16), 166 (29, [M].sup.+.-iBuOH), 139 (14), 130 (20), 124 (8), 111 (39), 109 (23), 95 (23), 83 (28), 74 (26), 69 (63), 57 (100), 55 (61), 41 (58), 29 (15).

(39) Odor description: fruity acidic, slightly agrestic.

f) Synthesis of allyl 2-(1,2,2-trimethylcyclopentyl)propanoate

(40) According to Example 3b, starting from 2-(1,2,2-trimethylcyclopentyl)propanoic acid (3.31 g, 18.0 mmol) and prop-2-en-1-ol (18.3 ml, 269 mmol), 1.91 g (44%, purity 93%) of allyl 2-(1,2,2-trimethylcyclopentyl)propanoate was obtained after purification by FC on SiO.sub.2 (hexane/EtOAc 98:2.fwdarw.95:5) as a mixture of two diastereomers (ratio 18:1) as a colorless oil.

(41) .sup.13C-NMR (CDCl.sub.3, 100 MHz); major isomer: =175.9 (s), 132.5 (d), 118.1 (t), 64.6 (t), 46.6 (s), 45.2 (d), 44.5 (s), 41.4 (t), 38.7 (t), 25.2 (q), 25.2 (q), 19.2 (t), 16.8 (q), 13.2 (q) ppm.

(42) MS (EI); major isomer: 224 (1, [M].sup.+.), 209 (2), 183 (5), 166 (24), 127 (11), 114 (17), 111 (15), 109 (49), 95 (22), 83 (20), 81 (16), 69 (100), 57 (35), 55 (61), 41 (75), 29 (7).

(43) Odor description: fruity acidic, chemical agrestic.

EXAMPLE 4

a) Synthesis of methyl 2-(1-methylspiro[4.4]nonan-1-yl)acetate

(44) According to Example 1 b, starting from methyl 6-cyclopentylidene-3-methylhex-2-enoate (prepared from cyclopentanone by methods known to the person skilled in the art) (4.17 g, 13.0 mmol), 1.23 g (44%, purity 98%) of methyl 2-(1-methylspiro[4.4]nonan-1-yl)acetate was obtained after purification by FC on SiO.sub.2 (hexane/EtOAc 95:5) as a colorless oil.

(45) .sup.1H NMR (CDCl.sub.3, 400 MHz): =3.65 (s, 3H), 2.29 (d, J=13.0 Hz, 1H), 2.20 (d, J=13.0 Hz, 1H), 1.79-1.73 (m, 1H), 1.68-1.53 (m, 9H), 1.51-1.38 (m, 2H), 1.30-1.19 (m, 2H), 0.96 (s, 3H) ppm.

(46) .sup.13C-NMR (CDCl.sub.3, 100 MHz): =173.8 (s), 56.6 (s), 51.1 (q), 45.0 (s), 41.4 (t), 37.3 (t), 36.8 (t), 33.0 (t), 32.8 (t), 24.2 (t), 24.0 (t), 20.9 (q), 19.6 (t) ppm.

(47) MS (EI): 195 (1, [M].sup.+.CH.sub.3), 178 (49, [M].sup.+.-MeOH), 167 (13), 137 (42), 136 (69), 129 (29), 121 (24), 108 (27), 96 (51), 95 (73), 94 (49), 93 (44), 82 (39), 81 (77), 74 (15), 67 (100), 59 (20), 55 (46), 41 (50), 29 (10).

(48) Odor description: fruity peppery, woody green, pine needle resinous terpenic.

b) Synthesis of methyl 2-(1-methylspiro[4.4]nonan-1-yl)propanoate

(49) According to Example 2b, starting from methyl 2-(1-methylspiro[4.4]nonan-1-yl)acetate (0.91 g, 4.33 mmol), 0.54 g (53%, purity 95%) of methyl 2-(1-methylspiro[4.4]nonan-1-yl)propanoate was obtained after purification by FC on SiO.sub.2 (hexane/EtOAc 99:1) as a mixture of two diastereomers (ratio 2.2:1) as a colorless oil.

(50) .sup.1H NMR (CDCl.sub.3, 400 MHz); mixture of two diastereomers: =3.63 (s, 3H), 3.62 (s, 3H), 2.67 (q, J=7.1 Hz, 1H), 2.64 (q, J=7.1 Hz, 1H), 1.84-1.18 (m, 28H), 1.14 (d, J=7.0 Hz, 3H), 1.13 (d, J=7.1 Hz, 3H), 1.00 (s, 3H), 1.00 (s, 3H) ppm.

(51) .sup.13C-NMR (CDCl.sub.3, 100 MHz); mixture of two diastereomers: =176.9 (s), 176.8 (s), 57.1 (s), 56.7 (s), 51.0 (q), 50.8 (q), 48.0 (s), 46.0 (s), 45.3 (d), 43.9 (d), 39.5 (t), 39.0 (t), 38.9 (t), 38.8 (t), 34.7 (t), 33.3 (t), 33.0 (t), 31.5 (t), 24.2 (t), 24.0 (t), 23.8 (t), 23.6 (t), 19.6 (t), 18.7 (t), 17.3 (q), 17.2 (q), 15.1 (q), 13.1 (q) ppm.

(52) MS (EI, tR=7.91 min); major isomer: 224 (2, [M].sup.+.), 209 (4), 192 (43, [M].sup.+.-MeOH), 181 (64), 137 (78), 136 (29), 121 (19), 115 (29), 110 (33), 109 (34), 95 (77), 93 (29), 88 (100), 83 (25), 81 (67), 79 (33), 69 (21), 67 (60), 59 (22), 55 (38), 41 (45), 29 (11).

(53) MS (EI, tR=8.10 min); minor isomer: 224 (2, [M].sup.+.), 209 (3), 192 (38, [M].sup.+.-MeOH), 165 (13), 137 (73), 136 (30), 110 (41), 109 (36), 95 (75), 93 (27), 88 (100), 83 (26), 81 (69), 79 (30), 67 (58), 59 (22), 55 (33), 41 (41), 29 (10).

(54) Odor description: fruity, woody ambery, myraldyl effect.

c) Synthesis of ethyl 2-(1-methylspiro[4.4]nonan-1-yl)acetate

(55) According to Example 1 b, starting from ethyl 6-cyclopentylidene-3-methylhex-2-enoate (prepared from cyclopentanone by methods known to the person skilled in the art) (6.29 g, 28.3 mmol), 5.77 g (88%, purity 96%) of ethyl 2-(1-methylspiro[4.4]nonan-1-yl)acetate was obtained after purification by distillation (Kugelrohr apparatus, 140 C., 0.06 torr) as a colorless oil.

(56) .sup.1H NMR (CDCl.sub.3, 400 MHz): =4.12 (q, J=7.1 Hz, 1H), 4.11 (q, J=7.1 Hz, 1H), 2.27 (d, J=13.0 Hz, 1H), 2.18 (d, J=13.0 Hz, 1H), 1.81-1.70 (m, 1H), 1.65-1.54 (m, 9H), 1.54-1.39 (m, 2H), 1.30-1.19 (m, 2H), 1.26 (t, J=7.1 Hz, 3H), 0.97 (s, 3H) ppm.

(57) .sup.13C-NMR (CDCl.sub.3, 100 MHz): =173.4 (s), 59.9 (t), 56.6 (s), 45.0 (s), 41.6 (t), 37.3 (t), 36.8 (t), 33.0 (t), 32.8 (t), 24.2 (t), 24.0 (t), 20.9 (q), 19.6 (t), 14.3 (q) ppm.

(58) MS (EI): 224 (1, [M].sup.+.), 209 (1), 195 (1), 178 (55, [M].sup.+.-EtOH), 143 (22), 137 (62), 136 (66), 121 (23), 115 (21), 108 (28), 107 (26), 96 (56), 95 (82), 94 (50), 93 (44), 88 (19), 81 (92), 79 (46), 67 (100), 55 (55), 41 (61), 29 (42).

(59) Odor description: fruity, woody ambery, myraldyl effect.

d) Synthesis of ethyl 2-(1-methylspiro[4.4]nonan-1-yl)propanoate

(60) According to Example 1 b, starting from ethyl 6-cyclopentylidene-2,3-dimethylhex-2-enoate (prepared from 5-cyclopentylidenepentan-2-one by methods known to the person skilled in the art) (4.51 g, 19.1 mmol), 4.19 g (90%, purity 98%) of ethyl 2-(1-methylspiro[4.4]nonan-1-yl)propanoate was obtained after purification by FC on SiO.sub.2 (hexane/EtOAc 99:1) as a mixture of two diastereomers (ratio 1.6:1) as a colorless oil.

(61) .sup.1H NMR (CDCl.sub.3, 400 MHz); mixture of two diastereomers: 5=4.15-4.03 (m, 4H), 2.64 (q, J=7.1 Hz, 1H), 2.61 (q, J=7.0 Hz, 1H), 1.87-1.21 (m, 28H), 1.25 (t, J=7.1 Hz, 3H), 1.25 (t, J=7.1 Hz, 3H), 1.14 (d, J=7.0 Hz, 3H), 1.13 (d, J=7.1 Hz, 3H), 1.01 (d, J=0.6 Hz, 3H), 1.00 (d, J=0.4 Hz, 3H) ppm.

(62) .sup.13C-NMR (CDCl.sub.3, 100 MHz); mixture of two diastereomers: 0.3=176.4 (s), 176.3 (s), 59.7 (t), 59.6 (t), 57.1 (s), 56.8 (s), 47.9 (s), 46.0 (s), 45.4 (d), 44.2 (d), 39.5 (t), 39.0 (t), 39.0 (t), 38.5 (t), 34.7 (t), 33.4 (t), 33.0 (t), 31.4 (t), 24.2 (t), 23.8 (t), 23.6 (t), 23.6 (t), 19.6 (t), 18.8 (t), 17.3 (q), 17.2 (q), 15.1 (q), 14.3 (q), 14.1 (q), 13.1 (q) ppm.

(63) MS (EI, tR=8.49 min); major isomer: 238 (2, [M].sup.+.), 223 (3), 192 (29, [M].sup.+.-EtOH), 165 (14), 137 (41), 129 (16), 111 (18), 110 (28), 109 (25), 102 (100), 95 (50), 83 (18), 81 (43), 79 (20), 69 (16), 67 (36), 55 (24), 41 (27), 29 (24).

(64) MS (EI, tR=8.28 min); minor isomer: 238 (2, [M].sup.+.), 223 (3), 195 (37), 192 (34, [M].sup.+. EtOH), 165 (11), 137 (46), 129 (19), 111 (18), 110 (24), 109 (24), 102 (100), 95 (49), 93 (20), 83 (18), 81 (44), 79 (22), 69 (18), 67 (37), 55 (27), 41 (30), 29 (27).

(65) Odor description: woody ambery, fruity winey, pear.

EXAMPLE 5

a) Synthesis of ethyl 2-(1-methyl-2-methylenecyclopentyl)propanoate

(66) A solution of (2-methylcyclopent-1-en-1-yl)methanol (3.33 g, 29.7 mmol), 1,1,1-triethoxypropane (17.7 ml, 89.1 mmol) and propionic acid (0.22 ml, 2.97 mmol) was stirred at 90 C. for 2 h and at 160 C. for 2 h while the volatiles were distilled off. After cooling to 25 C. and addition of H.sub.2O, the aq. layer was extracted with MTBE (2). The org. phases were washed with brine, dried (MgSO.sub.4), filtered and the filtrate was concentrated. The volatiles were further removed by distillation (Kugelrohr apparatus, 40 C., 0.07 torr) and the residue was purified by f lash chromatography on SiO.sub.2 (hexane/EtOAc 199:1.fwdarw.99:1.fwdarw.98:2) to yield 3.25 g (53%, purity 95%) of ethyl 2-(1-methyl-2-methylenecyclopentyl)propanoate as a mixture of two diastereomers (ratio 5.5:1) as a colorless oil.

(67) .sup.1H NMR (CDCl.sub.3, 400 MHz); mixture of two diastereomers: =4.93 (t, J=2.1 Hz, 1H), 4.90 (t, J=2.0 Hz, 1H), 4.77 (t, J=2.2 Hz, 1H), 4.70 (t, J=2.2 Hz, 1H), 4.12 (q, J=7.1 Hz, 2H), 4.08 (q, J=7.1 Hz, 2H), 2.59 (q, J=6.9 Hz, 1H), 2.55 (q, J=7.1 Hz, 1H), 2.47-2.26 (m, 4H), 2.14 (ddd, J=12.5, 8.1, 7.3 Hz, 1H), 2.00 (ddd, J=13.0, 9.0, 7.1 Hz, 1H), 1.77-1.53 (m, 4H), 1.48-1.39 (m, 2H), 1.27 (t, J=7.1 Hz, 3H), 1.24 (t, J=7.1 Hz, 3H), 1.16 (d, J=7.3 Hz, 3H), 1.10 (s, 3H), 1.09 (d, J=6.9 Hz, 3H), 1.08 (s, 3H) ppm.

(68) .sup.13C-NMR (CDCl.sub.3, 100 MHz); mixture of two diastereomers: =175.8 (s), 175.7 (s), 159.3 (s), 159.1 (s), 105.2 (t), 104.4 (t), 59.8 (t), 59.7 (t), 47.6 (d), 47.0 (s), 46.9 (s), 46.0 (d), 36.7 (t), 35.5 (t), 34.5 (t), 33.6 (t), 26.7 (q), 24.7 (q), 22.8 (t), 22.0 (t), 14.3 (q), 14.2 (q), 13.2 (q), 13.1 (q) ppm

(69) MS (EI, tR=6.04 min); major isomer: 196 (<1, [M].sup.+.), 181 (<1, [M].sup.+.CH.sub.3), 151 (1, [M].sup.+.-Eta), 123 (3), 109 (9), 102 (10), 96 (8), 95 (100), 93 (9), 79 (10), 74 (6), 67 (12), 55 (7), 53 (5), 45 (1), 41 (8), 29 (12).

(70) MS (EI, tR=5.95 min); minor isomer: 196 (<1, [M].sup.+.), 181 (<1, [M].sup.+.CH.sub.3), 151 (1, [M].sup.+.-EtO.sup..), 123 (1), 109 (10), 102 (11), 96 (8), 95 (100), 93 (7), 79 (10), 74 (6), 67 (10), 55 (6), 53 (4), 45 (1), 41 (7), 29 (11).

(71) Odor description: fruity banana, slightly agrestic, fruity red fruits strawberry apple.

b) Synthesis of ethyl 2-(4-methylspiro[2.4]heptan-4-yl)propanoate

(72) Chloroiodomethane (1.8 ml, 24.5 mmol) was added to a solution of ethyl 2-(1-methyl-2-methylenecyclopentyl)propanoate (1.50 g, 7.64 mmol) in 1,2-dichloroethane (25 ml) at 0 C. After the reaction mixture was stirred at 0 C. f or 10 min, diethylzinc (1.5 M in toluene, 8.2 ml, 12.2 mmol) was added at 0 C., and the suspension was stirred at 25 C. for 3 h. The reaction mixture was cooled to 0 C. an d again chloroiodomethane (1.8 ml, 24.5 mmol) followed by diethylzinc (1.5M in toluene, 8.2 ml, 12.2 mmol) were added. After further stirring of the suspension for 3 h, 1 M aq. HCl-solution was added, and the aq. layer was extracted with CH.sub.2Cl.sub.2 (3). The org. phases were dried (MgSO.sub.4), filtered and the filtrate was concentrated. The crude product was purified by flash chromatography on SiO.sub.2 (cyclohexane/EtOAc 99:1.fwdarw.98:2) to yield 0.91 g (47%, purity 83%) of ethyl 2-(4-methylspiro[2.4]heptan-4-yl)propanoate as a single isomer as a light yellow oil. An olfactive pure and colorless sample was obtained by further distillations.

(73) .sup.1H NMR (CDCl.sub.3, 400 MHz): =4.14-4.02 (m, 2H), 2.27 (q, J=6.9 Hz, 1H), 2.02 (ddd, J=13.0, 7.8, 6.9 Hz, 1H), 1.90 (dt, J=12.5, 8.6 Hz, 1H), 1.74-1.58 (m, 2H), 1.45 (ddd, J=13.0, 8.6, 6.0 Hz, 1H), 1.36 (ddd, J=12.5, 8.1, 4.3 Hz, 1H), 1.25 (t, J=7.1 Hz, 3H), 1.15 (d, J=6.9 Hz, 3H), 0.81 (s, 3H), 0.51-0.40 (m, 3H), 0.17-0.13 (m, 1H) ppm.

(74) .sup.13C-NMR (CDCl.sub.3, 100 MHz): =176.2 (s), 59.7 (t), 45.0 (d), 43.5 (s), 37.6 (t), 37.2 (2t), 29.9 (s), 22.0 (t), 21.3 (q), 14.2 (q), 13.6 (q), 11.1 (t), 8.6 (t) ppm.

(75) MS (EI): 210 (1, [M].sup.+.), 195 (1), 182 (8), 165 (5, [M].sup.+.-Eta), 109 (100), 108 (39), 102 (26), 93 (18), 81 (18), 79 (17), 74 (13), 67 (21), 55 (11), 41 (12), 29 (19).

(76) Odor description: fruity banana, fruity rosy apple green, reminiscent of isocyclocitral and -damascone.

EXAMPLE 6

a) Synthesis of ethyl 3,7-dimethylnona-2,6-dienoate

(77) Pd(Pb)/CaCO.sub.3 (Lindlar catalyst, 0.8 g) was added to a solution of 3-methylpent-1-yn-3-ol (16.4 g, 167 mmol) in hexane (250 ml) at 25 C. under Ar. The reaction flask was evacuated and refilled first with Ar then with hydrogen (3). The reaction mixture was stirred at 25 C. under hydrogen (1 atm) for 3 h, filtered through a pad of Celite and washed with hexane. The filtrate was concentrated to yield 12.6 g (57%, purity 75%) of 3-methylpent-1-en-3-ol.

(78) A mixture of 3-methylpent-1-en-3-ol (75% wt, 12.6 g, 95 mmol), 2-methoxyprop-1-ene (18.8 g, 260 mmol) and triethanolamine phosphate (0.15 g) was added to a pressure vessel with stirrer. The autoclave was flushed and heated to 110 C. (pressure 5 bar) for 40 min. The temperature was then raised to 200 C. (pressure 20 bar) and maintained for 1 h. After cooling of the reaction mixture to 25 C. and addition of H.sub.2O, the aq. layer was extracted with MTBE (2). The org. phases were washed with brine, dried (MgSO.sub.4), filtered and the filtrate was concentrated. The crude product was distilled over a Widmer column (b.p. 88 C., 26 mbar) to yield 5.49 g (41%) of 6-methyloct-5-en-2-one as a mixture of E/Z-isomers (ratio 1.5:1) as a colorless oil.

(79) Ethyl 2-(diethoxyphosphoryl)acetate (6.1 ml, 30.6 mmol) in THF (15 ml) was added to a suspension of sodium hydride (55% wt, 1.34 g, 30.6 mmol) in THF (15 ml) at 0-5 C. After the light yellow solution was stirred at 25 C. for 30 min, 6-methyloct-5-en-2-one (3.90 g, 27.8 mmol) in THF (15 ml) was added at 0-5 C., and the mixture was stirred at 0.fwdarw.75 C. for 2 h. After addition of H.sub.2O, the aq. layer was extracted with MTBE (2). The org. phases were washed with H.sub.2O and brine, dried (MgSO.sub.4), filtered and the filtrate was concentrated. The crude product was purified by flash chromatography on SiO.sub.2 (hexane/EtOAc 99:1) to yield 4.25 g (72%, purity 98%) of ethyl 3,7-dimethylnona-2,6-dienoate as a mixture of four E/Z-isomers (ratio 6:4:1.4:1) as a colorless oil.

(80) .sup.13C-NMR (CDCl.sub.3, 100 MHz); mixture of E/Z-isomers: =166.8 (s), 166.8 (s), 166.3 (s), 166.3 (s), 160.1 (s), 159.9 (s), 159.7 (s), 159.7 (s), 138.2 (s), 138.0 (s), 137.7 (s), 137.5 (s), 123.3 (d), 122.6 (d), 122.0 (d), 121.4 (d), 116.2 (d), 116.2 (d), 115.6 (d), 115.6 (d), 59.4 (t), 59.4 (t), 59.4 (t), 59.4 (t), 41.2 (t), 41.0 (t), 33.7 (t), 33.4 (t), 32.3 (t), 32.3 (t), 26.6 (t), 26.4 (t), 25.9 (t), 25.7 (t), 25.3 (q), 25.3 (q), 24.7 (t), 24.7 (t), 22.8 (2q), 18.8 (2q), 15.9 (q), 15.8 (q), 14.3 (4q), 12.8 (q), 12.7 (q), 12.7 (q), 12.7 (q) ppm.

(81) MS (EI); major isomer: 210 (1, [M].sup.+.), 195 (1), 165 (6), 137 (9), 128 (24), 100 (13), 83 (40), 82 (10), 67 (6), 55 (100), 41 (23), 29 (8).

b) Synthesis of ethyl 2-(2-ethyl-1,2-dimethylcyclopentyl)acetate

(82) According to Example 1 b, starting from ethyl 3,7-dimethylnona-2,6-dienoate (4.25 g, 19.9 mmol), 4.25 g (95%, purity 94%) of ethyl 2-(2-ethyl-1,2-dimethylcyclopentyl)-acetate was obtained after purification by distillation (Kugelrohr apparatus, 110 C., 0.06 torr) as a mixture of two diastereomers (ratio 1:1) as a colorless oil.

(83) .sup.13C-NMR (CDCl.sub.3, 100 MHz); mixture of two diastereomers: =173.6 (s), 173.6 (s), 59.9 (t), 59.9 (t), 47.0 (s), 46.9 (s), 46.3 (s), 45.8 (s), 42.0 (t), 41.0 (t), 37.4 (t), 36.3 (t), 35.9 (t), 34.6 (t), 28.5 (t), 27.8 (t), 21.3 (q), 21.1 (q), 20.4 (q), 19.7 (q), 19.4 (t), 19.4 (t), 14.3 (2q), 9.8 (q), 9.5 (q) ppm.

(84) MS (EI, tR=7.19 min); major isomer: 212 (1, [M].sup.+.), 197 (1), 183 (4), 169 (7), 167 (19), 166 (69, [M].sup.+.-EtOH), 125 (32), 124 (30), 109 (32), 98 (48), 95 (68), 88 (15), 83 (24), 69 (58), 55 (100), 43 (24), 41 (54), 29 (34).

(85) MS (EI, tR=7.16 min); minor isomer: 212 (1, [M].sup.+.), 197 (1), 183 (7), 169 (7), 167 (22), 166 (71, [M].sup.+.-EtOH), 125 (33), 124 (30), 109 (29), 98 (47), 95 (86), 88 (16), 83 (25), 69 (58), 55 (100), 43 (25), 41 (55), 29 (34).

(86) Odor description: fruity pungent, slightly woody.

c) Synthesis of ethyl 2-(2-ethyl-1,2-dimethylcyclopentyl)propanoate

(87) According to Example 2b, starting from ethyl 2-(2-ethyl-1,2-dimethylcyclopentyl)acetate (0.98 g, 4.93 mmol), 0.94 g (75%, purity 89%) of ethyl 2-(2-ethyl-1,2-dimethylcyclopentyl)propanoate was obtained after purification by FC on SiO.sub.2 (hexane/EtOAc 199:1.fwdarw.99:1) as a mixture of four diastereomers as a light yellow oil.

(88) .sup.13C-NMR (CDCl.sub.3, 100 MHz); mixture of four diastereomers: =176.5 (s), 176.4 (s), 176.3 (s), 176.3 (s), 59.7 (t), 59.6 (t), 59.6 (t), 59.6 (t), 49.3 (s), 49.3 (s), 47.8 (s), 47.7 (s), 47.6 (s), 47.5 (s), 47.2 (s), 46.9 (s), 45.0 (d), 44.3 (d), 44.1 (d), 43.5 (d), 38.7 (t), 38.6 (t), 38.3 (t), 38.2 (t), 37.5 (t), 37.3 (t), 34.7 (t), 34.1 (t), 30.3 (t), 28.4 (t), 27.4 (t), 25.9 (t), 20.8 (q), 20.6 (q), 19.8 (q), 19.3 (t), 19.1 (t), 18.6 (q), 18.5 (t), 18.3 (t), 17.5 (2q), 16.5 (q), 16.3 (q), 15.2 (q), 15.1 (q), 14.3 (q), 14.3 (q), 14.1 (q), 14.1 (q), 13.5 (q), 13.3 (q), 10.2 (q), 10.0 (q), 9.2 (q), 9.1 (q) ppm.

(89) MS (EI); major isomer: 126 (1, [M].sup.+.), 211 (2), 197 (6), 183 (14), 180 (34, [M].sup.+.-EtOH), 123 (24), 112 (31), 109 (21), 102 (100), 95 (70), 83 (41), 69 (62), 55 (86), 41 (53), 29 (27).

(90) Odor description: fruity apple, green.

d) Synthesis of ethyl 2,3,7-trimethyldeca-2,6-dienoate

(91) 3-Methylhex-1-yn-3-ol was converted into 3-methylhex-1-en-3-ol and then into 6-methylnon-5-en-2-one as described in Example 6a.

(92) Ethyl 2-(diethoxyphosphoryl)propanoate (5.5 ml, 25.5 mmol) in THF (13 ml) was added to a suspension of sodium hydride (55% wt, 0.62 g, 25.5 mmol) in THF (13 ml) at 0-5 C. After the light yellow solution was stirred at 25 C. for 30 min, 6-methylnon-5-en-2-one (3.58 g, 23.2 mmol) in THF (23 ml) was added at 0-5 C., and the mixture was stirred at 0.fwdarw.60 C. for 16 h. After addition of H.sub.2O, the aq. layer was extracted with MTBE (2). The org. phases were washed with H.sub.2O and brine, dried (MgSO.sub.4), filtered and the filtrate was concentrated. The crude product was purified by flash chromatography on SiO.sub.2 (hexane/EtOAc 199:1) to yield 2.64 g (48%, purity 100%) of ethyl 2,3,7-trimethyldeca-2,6-dienoate as a mixture of four E/Z-isomers (ratio 1.8:1.3:1.4:1) as a colorless oil.

(93) .sup.13C-NMR (CDCl.sub.3, 100 MHz); mixture of E/Z-isomers: =170.0 (s), 170.0 (s), 169.8 (s), 169.8 (s), 146.0 (s), 146.0 (s), 145.6 (s), 145.4 (s), 136.2 (s), 136.0 (s), 135.7 (s), 135.5 (s), 124.6 (d), 124.1 (d), 123.8 (d), 123.2 (d), 123.0 (s), 123.0 (s), 122.8 (s), 122.8 (s), 60.0 (2t), 60.0 (2t), 41.8 (2t), 36.7 (t), 36.5 (t), 36.4 (t), 36.2 (t), 33.7 (2t), 27.0 (t), 26.9 (t), 25.8 (t), 25.7 (t), 23.3 (2q), 21.1 (t), 21.1 (t), 21.0 (2q), 20.9 (t), 20.9 (t), 20.2 (q), 20.2 (q), 15.9 (2q), 15.8 (q), 15.7 (q), 15.3 (q), 15.3 (q), 14.3 (3q), 14.3 (q), 14.0 (2q), 13.7 (q), 13.7 (q) ppm.

(94) MS (EI); major isomer: 238 (1, [M].sup.+.), 223 (1), 193 (4), 165 (6), 142 (13), 97 (28), 96 (15), 67 (7), 55 (100), 43 (7), 41 (11), 29 (5).

e) Synthesis of ethyl 2-(1,2-dimethyl-2-propylcyclopentyl)propanoate

(95) According to Example 1b, starting from ethyl 2,3,7-trimethyldeca-2,6-dienoate (2.60 g, 10.9 mmol), 2.03 g (74%, purity 95%) of ethyl 2-(1,2-dimethyl-2-propylcyclopentyl)-propanoate was obtained after purification by FC on SiO.sub.2 (hexane/EtOAc 99:1.fwdarw.98:2) as a mixture of four diastereomers (ratio 2:2:1:1) as a colorless oil.

(96) .sup.13C-NMR (CDCl.sub.3, 100 MHz); mixture of four diastereomers: =176.5 (s), 176.4 (s), 176.4 (s), 176.3 (s), 59.7 (t), 59.7 (t), 59.6 (t), 59.6 (t), 49.4 (s), 49.3 (s), 47.7 (s), 47.6 (s), 47.6 (s), 47.4 (s), 47.0 (s), 46.9 (s), 45.0 (d), 44.3 (d), 44.1 (d), 43.5 (d), 40.8 (t), 38.8 (t), 38.5 (t), 38.4 (t), 38.3 (t), 38.2 (t), 38.1 (t), 38.0 (t), 37.9 (t), 36.5 (t), 35.6 (t), 35.0 (t), 21.6 (q), 21.4 (q), 20.6 (q), 19.5 (q), 19.4 (t), 19.2 (t), 19.1 (t), 19.0 (t), 18.6 (t), 18.5 (t), 18.1 (t), 18.0 (t), 17.4 (2q), 16.6 (q), 16.4 (q), 15.4 (q), 15.4 (q), 15.4 (q), 15.3 (q), 15.1 (q), 15.1 (q), 14.3 (q), 14.3 (q), 14.1 (q), 14.1 (q), 13.5 (q), 13.3 (q) ppm.

(97) MS (EI, tR=7.82 min); isomer 1: 240 (1, [M].sup.+.), 225 (2), 197 (17), 194 (25, [M].sup.+.-EtOH), 123 (16), 112 (32), 102 (100), 95 (66), 83 (62), 69 (50), 56 (25), 55 (87), 43 (28), 41 (53), 29 (25).

(98) MS (EI, tR=7.84 min); isomer 2: 240 (1, [M].sup.+.), 225 (2), 197 (14), 194 (24, [M].sup.+.-EtOH), 123 (16), 112 (34), 102 (100), 95 (34), 83 (60), 69 (47), 56 (24), 55 (84), 43 (26), 41 (50), 29 (23).

(99) MS (EI, tR=7.98 min); isomer 3: 240 (1, [M].sup.+.), 225 (1), 194 (19, [M].sup.+.-EtOH), 123 (13), 112 (29), 102 (100), 95 (47), 83 (61), 69 (47), 56 (25), 55 (80), 43 (23), 41 (46), 29 (22).

(100) MS (EI, tR=8.06 min); isomer 4: 240 (1, [M].sup.+.), 225 (1), 194 (19, [M].sup.+.-EtOH), 123 (13), 112 (29), 102 (100), 95 (32), 83 (59), 69 (46), 56 (25), 55 (77), 43 (23), 41 (44), 29 (21).

(101) Odor description: fruity apple physalis, natural, green, reminiscent of damascone.

EXAMPLE 7

a) Synthesis of ethyl 2-(1,2,2-trimethylcyclopentyl)acetate

(102) According to Example 1 b, starting from ethyl 3,7-dimethylocta-2,6-dienoate (49.1 g, 250 mmol), 18.3 g (35%, purity 95%) of ethyl 2-(1,2,2-trimethylcyclopentyl)acetate was obtained after purification by distillation (Kugelrohr apparatus, 125 C., 0.07 torr) as a colorless oil.

(103) .sup.1H NMR (CDCl.sub.3, 400 MHz): =4.12 (q, J=7.1 Hz, 1H), 4.11 (q, J=7.1 Hz, 1H), 2.24-2.16 (m, 2H), 1.89-1.81 (m, 1H), 1.68-1.56 (m, 4H), 1.51-1.43 (m, 1H), 1.26 (t, J=7.1 Hz, 3H), 0.94 (s, 3H), 0.88 (s, 3H), 0.86 (s, 3H) ppm.

(104) .sup.13C-NMR (CDCl.sub.3, 100 MHz): =173.5 (s), 59.9 (t), 45.2 (s), 43.9 (s), 41.6 (t), 39.0 (t), 36.8 (t), 24.5 (q), 23.5 (q), 21.1 (q), 19.4 (t), 14.3 (q) ppm.

(105) MS (EI): 198 (1, [M].sup.+.), 183 (5), 169 (1), 155 (24), 153 (45), 152 (100, [M].sup.+.-EtOH), 111 (68), 110 (79), 109 (42), 96 (24), 95 (68), 94 (30), 88 (22), 83 (19), 82 (20), 81 (18), 69 (67), 56 (25), 55 (52), 41 (53), 29 (47).

(106) Odor description: fruity raspberry, green acid waxy woody, fraistone.

b) Synthesis of ethyl 2-(1,2,2-trimethylcyclopentyl)butanoate

(107) Ethyl 2-(1,2,2-trimethylcyclopentyl)acetate (2.00 g, 10.1 mmol) in THF (10 ml) was added to a solution of LDA (freshly prepared from BuLi (6.9 ml, 11.1 mmol) and diisopropylamine (1.6 ml, 11.1 mmol)) in THF (11 ml) at 78 C. The mixture was stirred at 78 C. for 30 min before iodoethane (1.2 ml, 15.1 mmol) in HMPA (2.6 ml, 15.1 mmol) was added at 78 C. The mixture was stirred at 25 C. for 3 h. After addition of sat. aq. NH.sub.4Cl-solution, the aq. layer was extracted with MTBE (2). The org. phases were dried (MgSO.sub.4), filtered and the filtrate was concentrated. The residue was purified by flash chromatography on SiO.sub.2 (hexane/EtOAc 199:1.fwdarw.99:1) to yield 1.31 g (54%, purity 95%) of ethyl 2-(1,2,2-trimethylcyclopentyl)butanoate as a mixture of two diastereomers (ratio 5.7:1) as a colorless oil.

(108) .sup.1H NMR (CDCl.sub.3, 400 MHz); mixture of two diastereomers: =4.21-4.05 (m, 4H), 2.40 (dd, J=11.8, 3.4 Hz, 1H), 2.29 (dd, J=12.0, 3.1 Hz, 1H), 1.79-1.67 (m, 4H), 1.66-1.52 (m, 8H), 1.48-1.35 (m, 4H), 1.28 (t, J=7.1 Hz, 3H), 1.26 (t, J=7.1 Hz, 3H), 1.02 (s, 3H), 1.01 (s, 3H), 0.99 (s, 3H), 0.98 (d, J=0.6 Hz, 3H), 0.94 (s, 3H), 0.85 (t, J=7.4 Hz, 3H), 0.83 (t, J=7.7 Hz, 3H), 0.79 (s, 3H) ppm.

(109) .sup.13C-NMR (CDCl.sub.3, 100 MHz); mixture of two diastereomers: =175.7 (s), 175.6 (s), 59.6 (t), 59.6 (t), 53.8 (d), 53.2 (d), 48.4 (s), 46.8 (s), 44.5 (s), 44.0 (s), 41.5 (t), 41.2 (t), 39.0 (t), 38.6 (t), 25.6 (2q), 24.5 (q), 23.2 (t), 22.9 (q), 20.9 (t), 19.2 (t), 18.5 (t), 17.4 (q), 17.2 (q), 14.4 (q), 14.2 (q), 12.7 (q), 12.6 (q) ppm.

(110) MS (EI); mixture of two diastereomers: 226 (2, [M].sup.+.), 211 (4), 197 (23), 183 (20), 180 (55, [M].sup.+.-EtOH), 138 (16), 127 (25), 116 (100), 111 (24), 109 (35), 101 (23), 97 (19), 95 (30), 83 (20), 69 (41), 55 (43), 41 (31), 29 (23).

(111) Odor description: fruity agrestic, woody ambery.

c) Synthesis of ethyl 2-(1,2,2-trimethylcyclopentyl)pentanoate

(112) Ethyl 2-(1,2,2-trimethylcyclopentyl)acetate (2.00 g, 10.1 mmol) in THF (10 ml) was added to a solution of LDA (freshly prepared from BuLi (7.6 ml, 12.1 mmol) and diisopropylamine (1.7 ml, 12.1 mmol)) in THF (12 ml) at 78 C. The mixture was stirred at 78 C. for 40 min before 1-iodopropane (1.9 ml, 15.1 mmol) in HMPA (2.6 ml, 15.1 mmol) was added at 78 C. The mixture was stirred at 25 C. for 2 h. After addition of sat. aq. NH.sub.4Cl-solution, the aq. layer was extracted with MTBE (2). The org. phases were dried (MgSO.sub.4), filtered and the filtrate was concentrated. The residue was purified by flash chromatography on SiO.sub.2 (cyclohexane/EtOAc 199:1.fwdarw.99:1) to yield 0.98 g (39%, purity 97%) of ethyl 2-(1,2,2-trimethylcyclopentyl)pentanoate as a mixture of two diastereomers (ratio 3.5:1) as a colorless oil.

(113) .sup.1H NMR (CDCl.sub.3, 400 MHz); mixture of two diastereomers: =4.19-4.03 (m, 4H), 2.50 (dd, J=12.1, 2.8 Hz, 1H), 2.39 (dd, J=12.0, 2.8 Hz, 1H), 1.79-1.67 (m, 4H), 1.62-1.52 (m, 8H), 1.45-1.14 (m, 8H), 1.27 (t, J=7.1 Hz, 3H), 1.25 (t, J=7.1 Hz, 3H), 1.02 (s, 6H), 1.00 (s, 3H), 0.98 (d, J=0.6 Hz, 3H), 0.95 (s, 3H), 0.90 (t, J=7.2 Hz, 3H), 0.89 (t, J=7.2 Hz, 3H), 0.79 (s, 3H) ppm.

(114) .sup.13C-NMR (CDCl.sub.3, 100 MHz); mixture of two diastereomers: =175.8 (2s), 59.6 (t), 59.5 (t), 51.4 (d), 51.0 (d), 48.3 (s), 46.7 (s), 44.5 (s), 44.0 (s), 41.5 (t), 41.2 (t), 39.1 (t), 38.5 (t), 32.4 (t), 30.0 (t), 25.7 (q), 25.6 (q), 24.4 (q), 22.9 (q), 21.5 (t), 21.4 (t), 19.1 (t), 18.5 (t), 17.4 (q), 17.2 (q), 14.4 (q), 14.2 (q), 14.1 (q), 14.1 (q) ppm.

(115) MS (EI); mixture of two diastereomers: 240 (2, [M].sup.+.), 225 (3), 197 (41), 194 (43, [M].sup.+. EtOH), 152 (20), 130 (100), 127 (20), 123 (24), 111 (34), 109 (28), 101 (61), 95 (28), 81 (16), 69 (49), 55 (50), 41 (32), 29 (27).

(116) Odor description: fruity agrestic, strawberry, apple.

EXAMPLE 8: SYNTHESIS OF ETHYL 2-(1-ETHYL-2,2-DIMETHYLCYCLOPENTYL)PROPANOATE

a) Synthesis of ethyl 3-ethyl-2,7-dimethylocta-2,6-dienoate

(117) According to Example 1a, starting from 7-methyloct-6-en-3-one (prepared by methods known to the person skilled in the art) (2.80 g, 20.0 mmol), 1.16 g (25%, purity 98%) of ethyl 3-ethyl-2,7-dimethylocta-2,6-dienoate was obtained after purification by FC on SiO.sub.2 (hexane/EtOAc 99:1) (mixture of E/Z-isomers; ratio 1.3:1) as a colorless oil.

(118) .sup.1H NMR (CDCl.sub.3, 400 MHz); mixture of E/Z-isomers: =5.16-5.10 (m, 2H), 4.18 (q, J=7.2 Hz, 2H), 4.17 (q, J=7.2 Hz, 2H), 2.34-2.29 (m, 4H), 2.17-2.05 (m, 8H), 1.86 (br. s, 6H), 1.69 (q, J=0.9 Hz, 3H), 1.68 (br. q, J=1.0 Hz, 3H), 1.61 (br. s, 6H), 1.30 (t, J=7.2 Hz, 3H), 1.29 (t, J=7.2 Hz, 3H), 1.05 (t, J=7.5 Hz, 3H), 1.02 (t, J=7.6 Hz, 3H) ppm.

(119) .sup.13C-NMR (CDCl.sub.3, 100 MHz); mixture of E/Z-isomers: =170.0 (2s), 151.0 (s), 150.9 (s), 132.2 (s), 131.7 (s), 124.1 (d), 123.7 (d), 122.8 (s), 122.8 (s), 60.0 (2t), 34.0 (t), 33.3 (t), 27.5 (t), 27.4 (t), 26.7 (t), 26.3 (t), 25.7 (2q), 17.6 (q), 17.6 (q), 15.4 (q), 15.3 (q), 14.3 (q), 14.3 (q), 13.3 (q), 12.1 (q) ppm.

(120) MS (EI, tR=7.40 min); major isomer: 224 (4, [M].sup.+.), 179 (27, [M].sup.+.-Eta), 156 (22), 151 (27), 150 (16), 141 (17), 127 (21), 123 (17), 113 (16), 110 (46), 109 (14), 69 (100), 67 (17), 53 (11), 41 (50), 29 (14).

(121) MS (EI, tR=7.32 min); minor isomer: 224 (4, [M].sup.+.), 179 (21, [M].sup.+.-Eta), 156 (35), 151 (43), 150 (20), 141 (21), 127 (30), 123 (17), 113 (24), 110 (66), 109 (22), 69 (100), 67 (21), 53 (13), 41 (58), 29 (19).

b) Synthesis of ethyl 2-(1-ethyl-2,2-dimethylcyclopentyl)propanoate

(122) According to Example 1 b, starting from ethyl 3-ethyl-2,7-dimethylocta-2,6-dienoate (1.16 g, 5.17 mmol), 0.70 g (57%, purity 96%) of ethyl 2-(1-ethyl-2,2-dimethylcyclopentyl)propanoate was obtained after purification by FC on SiO.sub.2 (hexane/EtOAc 99:1) as a mixture of two diastereomers (ratio 2.1:1) as a colorless oil.

(123) .sup.13C-NMR (CDCl.sub.3, 100 MHz); mixture of two diastereomers: =177.3 (s), 176.6 (s), 59.9 (t), 59.7 (t), 50.8 (s), 50.4 (s), 45.7 (s), 45.4 (s), 44.6 (d), 43.7 (d), 42.2 (t), 41.9 (t), 33.5 (t), 33.3 (t), 26.3 (q), 26.1 (q), 25.4 (q), 24.7 (t), 24.3 (t), 23.8 (q), 20.2 (t), 19.8 (t), 16.2 (q), 14.1 (q), 14.1 (q), 13.7 (q), 11.2 (q), 9.9 (q) ppm.

(124) MS (EI, tR=7.43 min); major isomer: 226 (1, [M].sup.+.), 211 (4), 197 (11), 180 (25, [M].sup.+. EtOH), 155 (8), 141 (18), 125 (25), 124 (20), 123 (25), 109 (26), 102 (100), 95 (38), 83 (31), 74 (13), 69 (48), 55 (38), 41 (28), 29 (23).

(125) MS (EI, tR=7.41 min); minor isomer: 226 (1, [M].sup.+.), 211 (3), 197 (12), 180 (23, [M].sup.+. EtOH), 155 (8), 141 (14), 125 (25), 124 (17), 123 (22), 109 (25), 102 (100), 95 (35), 83 (27), 74 (14), 69 (41), 55 (34), 41 (27), 29 (23).

(126) Odor description: fruity, red fruits, cherry, plumy, slightly woody.

EXAMPLE 9: SYNTHESIS OF ETHYL 2-(1,2-DIMETHYLCYCLOPENTYL)PROPANOATE

(127) Pd/C (5 wt %, 0.2 g) was added to a solution of ethyl 2-(1-methyl-2-methylene-cyclopentyl)propanoate (Example 5a) (1.86 g, 9.46 mmol) in EtOH (40 ml) at 25 C. under Ar. The reaction flask was evacuated and refilled first with Ar then with hydrogen (3). The reaction mixture was stirred at 25 C. under hydrogen (1 atm) for 2 h, filtered through a pad of Celite and washed with EtOH. The filtrate was concentrated and 1.33 g (70%, purity 98%) of ethyl 2-(1,2-dimethylcyclopentyl)propanoate was obtained after purification by FC on SiO.sub.2 (hexane/EtOAc 99:1.fwdarw.98:2) as a mixture of two diastereomers (ratio 8:1) as a colorless oil.

(128) .sup.13C-NMR (CDCl.sub.3, 100 MHz); major isomer: =176.4 (s), 59.8 (t), 47.4 (d), 45.1 (s), 39.9 (d), 36.7 (t), 32.8 (t), 21.4 (t), 18.1 (q), 14.3 (q), 14.3 (q), 12.9 (q) ppm.

(129) MS (EI); major isomer: 198 (1, [M].sup.+.), 183 (2), 153 (5, [M].sup.+.-EtOH), 141 (3), 125 (11), 102 (100), 97 (19), 83 (8), 81 (7), 74 (16), 69 (15), 55 (21), 45 (2), 41 (14), 29 (11).

(130) Odor description: fruity agrestic, strawberry peppery.

EXAMPLE 10: SYNTHESIS OF VARIOUS NITRILES

a) Synthesis of 2-(1,2,2-trimethylcyclopentyl)acetonitrile

(131) According to Example 1 b, starting from 3,7-dimethylocta-2,6-dienenitrile (14.9 g, 100 mmol), 14.4 g (92%, purity 97%) of 2-(1,2,2-trimethylcyclopentyl)acetonitrile was obtained after purification by distillation (Kugelrohr apparatus, 120 C., 0.07 torr) as a white solid.

(132) .sup.1H NMR (CDCl.sub.3, 400 MHz): =2.30-2.20 (m, 2H), 1.84-1.76 (m, 1H), 1.69-1.60 (m, 4H), 1.58-1.50 (m, 1H), 1.08 (s, 3H), 0.94 (s, 3H), 0.90 (s, 3H) ppm.

(133) .sup.13C-NMR (CDCl.sub.3, 100 MHz): =119.5 (s), 45.0 (s), 43.2 (s), 39.3 (t), 37.1 (t), 25.8 (t), 24.2 (q), 24.0 (q), 21.4 (q), 19.0 (t) ppm.

(134) MS (EI): 151 (2, [M].sup.+.), 150 (14), 136 (76), 122 (30), 111 (21), 109 (30), 108 (61), 96 (19), 95 (57), 94 (40), 83 (21), 82 (17), 81 (17), 70 (50), 69 (72), 67 (23), 56 (35), 55 (100), 41 (70), 39 (33), 29 (11), 27(14).

(135) Odor description: agrestic green bornyl minty, fatty citrus Citral-like.

b) Synthesis of 2-(1,2,2-trimethylcyclopentyl)propanenitrile

(136) According to Example 2b, starting from 2-(1,2,2-trimethylcyclopentyl)acetonitrile (7.56 g, 50.0 mmol), 7.30 g (88%, purity 100%) of 2-(1,2,2-trimethylcyclopentyl)propanenitrile was obtained after purification by distillation (Kugelrohr apparatus, 150 C., 0.06 torr) as a mixture of two diastereomers as a light yellow solid.

(137) .sup.1H NMR (CDCl.sub.3, 400 MHz); mixture of two diastereomers: =2.77 (q, J=7.1 Hz, 1H), 2.63 (q, J=7.1 Hz, 1H), 1.88-1.44 (m, 12H), 1.29 (d, J=7.1 Hz, 3H), 1.28 (d, J=7.3 Hz, 3H), 1.14 (s, 3H), 1.05 (s, 3H), 1.02 (s, 3H), 0.99 (s, 3H), 0.98 (s, 3H), 0.94 (s, 3H) ppm.

(138) .sup.13C-NMR (CDCl.sub.3, 100 MHz); mixture of two diastereomers: =123.2 (s), 122.6 (s), 46.7 (s), 46.5 (s), 43.9 (s), 43.4 (s), 41.9 (t), 40.9 (t), 39.9 (t), 37.2 (t), 33.7 (d), 30.9 (d), 25.0 (q), 24.9 (q), 24.7 (q), 23.6 (q), 19.0 (t), 18.3 (t), 17.9 (2q), 15.3 (q), 14.2 (q) ppm.

(139) MS (EI, tR=6.07 min); major isomer: 165 (2, [M].sup.+.), 164 (6), 150 (52), 123 (21), 111 (27), 108 (91), 95 (57), 82 (21), 70 (42), 69 (88), 67 (20), 56 (24), 55 (100), 41 (58), 39 (24), 29 (10), 27(11).

(140) MS (EI, tR=6.21 min); minor isomer: 165 (2, [M].sup.+.), 164 (6), 150 (47), 123 (20), 111 (40), 108 (83), 95 (51), 82 (19), 70 (38), 69 (93), 67 (19), 56 (24), 55 (100), 53 (18), 41 (56), 39 (23), 29 (10), 27(10).

(141) Odor description: agrestic fruity, ketonic.

d) Synthesis of 2-(2-ethyl-1,2-dimethylcyclopentyl)acetonitrile

(142) According to Example 1 b, starting from 3,7-dimethylnona-2,6-dienenitrile (4.08 g, 25 mmol), 2.65 g (62%, purity 97%) of 2-(2-ethyl-1,2-dimethylcyclopentyl)acetonitrile was obtained after purification by FC on SiO.sub.2 (hexane/EtOAc 99:1.fwdarw.98:2) as a mixture of two diastereomers (ratio 1:1) as a colorless oil.

(143) .sup.13C-NMR (CDCl.sub.3, 100 MHz); mixture of two diastereomers: =119.6 (s), 119.4 (s), 46.1 (s), 46.1 (s), 46.0 (s), 45.4 (s), 37.5 (t), 37.0 (t), 35.9 (t), 35.5 (t), 28.4 (t), 28.2 (t), 25.8 (t), 25.5 (t), 21.5 (q), 21.3 (q), 20.2 (q), 20.1 (q), 19.0 (t), 18.9 (t), 9.5 (q), 9.4 (q) ppm.

(144) MS (EI, tR=6.50 min); isomer 1: 165 (1, [M].sup.+.), 164 (4), 150 (41), 136 (38), 122 (37), 109 (13), 108 (16), 95 (79), 83 (23), 70 (18), 69 (45), 67 (19), 56 (24), 55 (100), 53 (21), 41 (53), 39 (21), 29 (11), 27(10).

(145) MS (EI, tR=6.52 min); isomer 2: 165 (1, [M].sup.+.), 164 (6), 150 (53), 136 (46), 122 (44), 109 (18), 108 (18), 95 (84), 83 (22), 70 (21), 69 (51), 67 (22), 56 (27), 55 (100), 53 (22), 41 (56), 39 (23), 29 (12), 27(10).

(146) Odor description: citrus green agrestic, minty, fruity.

EXAMPLE 11

a) Synthesis of ethyl 2-(2,2-dimethylcyclopentyl)propanoate

(147) According to Example 1 b, starting from (E)-ethyl 2,7-dimethylocta-2,6-dienoate (prepared from 5-methylhex-4-enal by methods known to the person skilled in the art) (2.66 g, 13.6 mmol), 1.78 g (58%, purity 88%) of ethyl 2-(2,2-dimethylcyclopentyl)propanoate was obtained after purification by FC on SiO.sub.2 (hexane/EtOAc 99:1.fwdarw.98:2) as a mixture of two diastereomers (ratio 9:1) as a colorless oil. Further purification yielded 0.47 g (purity 93%) of the two diastereomers (ratio 15:1) of ethyl 2-(2,2-dimethylcyclopentyl)-propanoate.

(148) .sup.13C-NMR (CDCl.sub.3, 100 MHz); major isomer: =177.0 (s), 59.9 (t), 51.9 (d), 43.8 (t), 42.1 (d), 40.6 (s), 30.1 (t), 30.1 (q), 21.7 (q), 21.1 (t), 17.4 (q), 14.2 (q) ppm.

(149) MS (EI); major isomer: 198 (2, [M].sup.+.), 183 (6, [M].sup.+.CH.sub.3), 152 (55, [M].sup.+.-EtOH), 125 (22), 124 (18), 115 (11), 109 (24), 102 (100), 95 (13), 83 (16), 82 (21), 81 (18), 74 (20), 69 (40), 55 (40), 41 (31), 29 (25).

(150) Odor description: fruity, winey, fatty, floral.

b) Synthesis of ethyl 2-(2,2-dimethylcyclopentyl)acetate

(151) According to Example 1b, starting from (E)-ethyl 7-methylocta-2,6-dienoate (prepared from 5-methylhex-4-enal by methods known to the person skilled in the art) (5.51 g, 30.2 mmol), 5.43 g (88%, purity 90%) of ethyl 2-(2,2-dimethylcyclopentyl)acetate was obtained. Purification by FC on SiO.sub.2 (hexane/EtOAc 99:1.fwdarw.98:2) yielded 1.73 g (30%, purity 96%) of ethyl 2-(2,2-dimethylcyclopentyl)acetate as a colorless oil.

(152) .sup.1H NMR (CDCl.sub.3, 400 MHz): =4.12 (q, J=7.2 Hz, 2H), 2.36 (dd, J=14.5, 4.1 Hz, 1H), 2.36 (dd, J=14.6, 10.4 Hz, 1H), 1.98-1.81 (m, 2H), 1.62-1.55 (m, 2H), 1.46-1.39 (m, 2H), 1.38-1.29 (m, 1H), 1.25 (t, J=7.2 Hz, 3H), 0.98 (s, 3H), 0.75 (s, 3H) ppm.

(153) .sup.13C-NMR (CDCl.sub.3, 100 MHz): =174.0 (s), 60.1 (t), 45.9 (d), 41.4 (t), 40.5 (s), 35.5 (t), 30.4 (t), 27.7 (q), 21.7 (q), 21.0 (t), 14.2 (q) ppm.

(154) MS (EI): 184 (2, [M].sup.+.), 169 (6, [M].sup.+.-CH.sub.3), 142 (15), 141 (33), 139 (50), 138 (100, [M].sup.+.-EtOH), 129 (11), 123 (12), 111 (18), 110 (39), 101 (15), 96 (25), 95 (45), 88 (28), 82 (24), 81 (29), 70 (20), 69 (43), 67 (15), 56 (16), 55 (43), 45 (4), 43 (15), 41 (37), 29 (24).

(155) Odor description: fruity red fruits, slightly winey.

c) Synthesis of ethyl 2-(2,2-dimethylcyclopentyl)propanoate

(156) According to Example 2b, starting from ethyl 2-(2,2-dimethylcyclopentyl)acetate (1.72 g, 9.33 mmol), ethyl 2-(2,2-dimethylcyclopentyl)propanoate was obtained as a mixture of two diastereomers (ratio 3.5:1; the major diastereomer of this example corresponds to the minor diastereomer of example 11a.) as a light yellow oil. Olfactive purification by FC on SiO.sub.2 (hexane/EtOAc 99:1.fwdarw.98:2) yielded 1.37 g (65%, purity 88%) and 0.06 g (3%, purity 95%) of the major isomer of ethyl 2-(2,2-dimethylcyclopentyl) propanoate as a colorless oil.

(157) .sup.1H NMR (CDCl.sub.3, 400 MHz); major isomer: =4.16-4.07 (m, 2H), 2.33-2.25 (m, 1H), 1.93-1.85 (m, 1H), 1.75 (td, J=10.6, 8.1 Hz, 1H), 1.59-1.30 (m, 5H), 1.27 (t, J=7.2 Hz, 3H), 1.12 (d, J=7.0 Hz, 3H), 0.91 (s, 3H), 0.84 (s, 3H) ppm.

(158) .sup.13C-NMR (CDCl.sub.3, 100 MHz); major isomer: =177.2 (s), 59.9 (t), 51.7 (d), 43.2 (t), 41.0 (d), 40.5 (s), 29.2 (t), 28.2 (q), 21.6 (q), 20.3 (t), 17.7 (q), 14.1 (q) ppm.

(159) MS (EI); major isomer: 198 (3, [M].sup.+.), 183 (11, [M].sup.+.CH.sub.3), 155 (73), 153 (25), 152 (92, [M].sup.+.-EtOH), 127 (28), 125 (36), 124 (30), 115 (19), 109 (52), 102 (100), 95 (26), 83 (28), 82 (40), 81 (34), 74 (21), 70 (23), 69 (73), 67 (27), 55 (79), 41 (67), 29 (51).

(160) .sup.13C-NMR and MS data for minor isomer see Example 11a above.

(161) Odor description (major isomer): fruity red fruits, strawberry, rosy physalis, slightly winey.

EXAMPLE 12

a) Synthesis of ethyl 2-(2,2-dimethylcyclohexyl)propanoate

(162) Hydrogen chloride (2M in H.sub.2O, 5.3 ml, 10.5 mmol) was added to a solution of 1-methoxy-6-methylhepta-1,5-diene (prepared from 5-methylhex-4-enal by methods known to the person skilled in the art) (14.7 g, 105 mmol) in THF (250 ml) at 0 C. and the reaction mixture was stirred at 0 C. for 7 h. After addition of 2M aq. NaOH-solution, the aq. layer was extracted with MTBE. The org. phases were washed with H.sub.2O and brine, dried (MgSO.sub.4), filtered and the filtrate was concentrated to yield 15.9 g (83%, purity 69%) of 6-methylhept-5-enal as a yellow oil.

(163) Ethyl 2-(diethoxyphosphoryl)propanoate (1.98 g, 8.33 mmol) in DME/NMP (4 ml, 3:1) was added to a suspension of sodium hydride (50% wt, 0.38 g, 7.88 mmol) in DME (3 ml) at 25-50 C. After the yellow suspension was stirred at 25 C. for 30 min, 6-methylhept-5-enal (0.95 g, 7.50 mmol) in DME (1 ml) was added at 15-20 C. The reaction mixture was stirred at 25 C. for 1 h, water was added and the aq. layer was extracted with MTBE (2). The org. phases were washed with H.sub.2O and brine, dried (MgSO.sub.4), filtered and the filtrate was concentrated to yield 1.77 g (quant., purity 90%) of ethyl 2,8-dimethylnona-2,7-dienoate (mixture of E/Z-isomers; ratio 2.2:1).

(164) According to Example 1 b, starting from purified (E)-ethyl 2,8-dimethylnona-2,7-dienoate (0.50 g, 2.38 mmol), 0.49 g (79%, purity 81%) of ethyl 2-(2,2-dimethylcyclohexyl)propanoate was obtained as a mixture of two diastereomers (ratio 12:1). An olfactive pure sample was obtained by purification by FC on SiO.sub.2 (Biotage Isolera, hexane/EtOAc 100:0.fwdarw.9:1) as a colorless oil.

(165) .sup.13C-NMR (CDCl.sub.3, 100 MHz); major isomer: =176.4 (s), 59.8 (t), 52.2 (d), 43.3 (t), 39.2 (d), 34.4 (s), 30.9 (q), 27.3 (t), 24.0 (t), 22.3 (t), 19.8 (q), 19.0 (q), 14.1 (q) ppm.

(166) MS (EI); major isomer: 212 (1, [M].sup.+.), 197 (1, [M].sup.+.CH.sub.3), 167 (5, [M].sup.+.-EtO.sup..), 151 (4), 139 (3), 123 (9), 111 (5), 102 (100), 95 (9), 83 (11), 74 (14), 69 (20), 55 (17), 41 (19), 29 (17).

(167) Odour description: fruity, red fruits, woody ambery, plumy, orris, irone effect.

b) Synthesis of ethyl 2-(1,2,2-trimethylcyclohexyl)acetate

(168) Ethyl 2-(diethoxyphosphoryl)acetate (4.61 g, 20.6 mmol) in DME/NMP (12 ml, 3:1) was added to a suspension of sodium hydride (50% wt, 0.93 g, 19.5 mmol) in DME (9 ml) at 25-50 C. After the yellow suspension was stirred at 25 C. for 30 min, 7-methyloct-6-en-2-one (prepared from 6-methylhept-5-enal by methods known to the person skilled in the art) (2.60 g, 18.5 mmol) in DME (3 ml) was added at 25 C. The reaction mixture was stirred at 25 C. for 1 h, water was added and the aq. layer was extracted with MTBE (2). The org. phases were washed with H.sub.2O and brine, dried (MgSO.sub.4), filtered and the filtrate was concentrated. Purification by distillation (Kugelrohr apparatus, 150 C., 0.07 torr) yielded 2.25 g (47%, purity 81%) of ethyl 3,8-dimethylnona-2,7-dienoate (mixture of E/Z-isomers; ratio 2.1:1; the impurity corresponds to (E/Z)-ethyl 3,8-dimethylnona-3,7-dienoate).

(169) According to Example 1 b, starting from further purified ethyl 3,8-dimethylnona-2,7-dienoate (0.61 g, 2.78 mmol), 0.43 g (53%, purity 73%) of ethyl 2-(1,2,2-trimethylcyclohexyl)acetate was obtained after purification by FC on SiO.sub.2 (Biotage Isolera, hexane/EtOAc 100:0.fwdarw.9:1) as a colorless oil.

(170) .sup.13C-NMR (CDCl.sub.3, 100 MHz): =173.4 (s), 59.8 (t), 41.2 (t), 38.3 (s), 37.1 (t), 35.8 (s), 33.3 (t), 24.6 (q), 24.1 (q), 22.1 (2t), 20.5 (q), 14.3 (q) ppm.

(171) MS (EI): 212 (3, [M].sup.+.), 197 (2, [M].sup.+.CH.sub.3), 167 (25), 166 (36, [M].sup.+.-EtOH), 151 (37), 125 (100), 124 (50), 109 (49), 95 (18), 88 (47), 83 (28), 69 (74), 55 (57), 41 (59), 29 (53).

(172) Odour description: fruity, red fruits, agrestic, piney.

c) Synthesis of ethyl 2-(1,2,2-trimethylcyclohexyl)propanoate

(173) According to Example 2b, starting from ethyl 2-(1,2,2-trimethylcyclohexyl)acetate (0.30 g, purity 68%, 0.96 mmol), 0.31 g (78%, purity 55%) of ethyl 2-(1,2,2-trimethylcyclohexyl)propanoate was obtained as a mixture of two diastereomers. Purification by FC on SiO.sub.2 (Biotage Isolera, hexane/EtOAc 100:0.fwdarw.9:1) yielded 0.13 g (41%, purity 69%) of ethyl 2-(1,2,2-trimethylcyclohexyl)propanoate a mixture of two diastereomers (ratio 1.5:1) as a colorless oil.

(174) .sup.13C-NMR (CDCl.sub.3, 100 MHz); mixture of two diastereomers: =177.5 (s), 177.0 (s), 59.8 (t), 59.7 (t), 45.3 (d), 44.1 (d), 40.7 (s), 40.3 (s), 39.0 (t), 38.8 (t), 36.9 (s), 36.8 (s), 33.1 (t), 32.7 (t), 26.6 (q), 26.2 (q), 23.5 (q), 22.6 (q), 22.1 (t), 22.1 (2t), 21.7 (t), 17.1 (q), 15.7 (q), 15.4 (q), 14.2 (q), 14.1 (q), 14.0 (q) ppm.

(175) MS (EI); mixture of two diastereomers: 226 (3, [M].sup.+.), 211 (3, [M].sup.+.CH.sub.3), 180 (9, [M].sup.+. EtOH), 125 (27), 123 (11), 109 (13), 102 (100), 97 (11), 83 (22), 81 (10), 74 (12), 69 (53), 67 (12), 57 (17), 56 (10), 55 (31), 43 (12), 41 (32), 29 (28).

(176) Odour description: fruity agrestic, woody ambery, myraldyl effect.

EXAMPLE 13: PREPARATION OF A FEMININE FLORAL FINE FRAGRANCE

(177) TABLE-US-00001 parts by weight Compound/Ingredient 1/1000 2-Methyl-1-phenylpropan-2-yl acetate (Dimethyl benzyl 100 carbinyl acetate) (E)-2-benzylideneoctanal (Hexyl cinnamic aldehyde) 200 cis-3-Hexenyl benzoate 2 3,7-Dimethyloct-6-en-1-ol (Citronellol) 110 6-Pentyltetrahydro-2H-pyran-2-one (Decalactone delta) 4 (at 10% in DEP) 3-(3-Isopropylphenyl)butanal (Florhydral) 2 3,7-Dimethyloct-6-en-1-yl formate (Citronellyl formate) 10 cis-3-Hexenol 10 Indole (at 1% in TEC) 60 3-(4-(tert-Butyl)phenyl)-2-methylpropanal (Lilial) 60 3,7-Dimethylocta-1,6-dien-3-ol (Linalool) 80 6-Methylhept-5-en-2-one 2 Hexyl 2-hydroxybenzoate (Hexyl Salicylate) 50 (E)-4-Methyldec-3-en-5-ol (Undecavertol) 120 Methyl-2-((3-(4-(tert-butyl)phenyl)-2-methylprop-1-en-1- 10 yl)amino)benzoate (Verdantiol) Dipropylene glycol (DPG) 150 Ethyl 2-(1,2,2-trimethylcyclopentyl)propanoate (Example 1b) 30 Total: 1000

(178) This soft floral accord with a clear linden blossom character is best to be assessed at 5 weight % in alcohol. The addition of ethyl 2-(1,2,2-trimethylcyclopentyl)propanoate impacts the top note by providing a fresh fruity effect. Ethyl 2-(1,2,2-trimethylcyclopentyl)propanoate combines well with the watery muguet elements and adds a soft fruity watermelon aspect.

EXAMPLE 14: PREPARATION OF A UNISEX MUSK ACCORD

(179) TABLE-US-00002 parts by weight Compound/Ingredient 1/1000 Geranyl acetate 10 Phenyl ethyl alcohol 60 Ambermax* (at 10% in TEC) 50 (3aR,5aS,9aS,9bR)-3a,6,6,9a-Tetramethyldodecahydro- 10 naphtho[2,1-b]furan (Ambrofix) 1,4-Dioxacycloheptadecane-5,17-dione (Brassylate 320 Ethylene) 3,7-Dimethylocta-2,6-dienal (Citral Lemarome N) 1 (E)-1-(2,6,6-Trimethylcyclohexa-1,3-dien-1-yl)but- 2 2-en-1-one (Damascenone) 4,6,6,7,8,8-Hexamethyl-1,3,4,6,7,8-hexahydro- 250 cyclopenta[g]isochromene (Galaxolide) Methyl 2-(3-oxo-2-pentylcyclopentyl)acetate 60 (Hedione) (1-Methyl-2-[(-1,2,2-trimethylbicyclo[3.1.0]hexan- 5 3-yl)methyl]cyclopropyl)methanol (Javanol) 3-Methyl-5-phenylpentan-1-ol (Mefrosol) 50 4-Methyl-2-(2-methylprop-1-enyl)tetrahydro-2H-pyran 2 (Rose Oxide CO) (at 10% in DEP) Oxacyclohexadecan-2-one (Thibetolide) 150 Ethyl 2-(1,2,2-trimethylcyclopentyl)propanoate 30 (Example 1b) Total: 1000 *Ambermax (mixture of 2-(1,1,5,5-tetramethyl-1,3,4,5,6,7-hexahydro-2H-2,4a- methanonaphthalen-8-yl)propan-1-ol and 2-(1,1,5,5-tetramethyl-1,3,4,5,6,8a-hexahydro-2H-2,4a-methanonaphthalen-8-yl)propan-1-ol)

(180) This soft musky rosy accord with a strong dry woody ambery facet is best to be assessed at 5 weight % in alcohol. The addition of ethyl 2-(1,2,2-trimethylcyclopentyl)-propanoate covers the impacting dry ambery note. Ethyl 2-(1,2,2-trimethylcyclopentyl)-propanoate combines well with the rose to provide a bright fruity effect with appR1 and plum facets.