Organic compounds

Abstract

The present invention refers to indanone derivatives of formula (I) ##STR00001## wherein R.sup.1 is selected from hydrogen, methyl and ethyl; R.sup.2 is selected from hydrogen, methyl and ethyl, and R is selected from hydrogen and methyl; or R.sup.2 and R.sup.3 form together with the carbon atoms to which they are attached C.sub.3-C.sub.5 cycloalkyl; and R.sup.4 is selected from C.sub.2-C.sub.5 alkyl, C.sub.2-C.sub.5 alkenyl, C.sub.1-C.sub.4 alkoxy, C.sub.3-C.sub.5 cycloalkyl, and C.sub.3-C.sub.6 cycloalkenyl. The invention further refers to perfume compositions and fragrance applications comprising them.

Claims

1. A fragrance composition comprising as odorant a compound of formula (I) ##STR00004## wherein R.sup.1 is selected from hydrogen, methyl and ethyl; R.sup.2 is selected from hydrogen, methyl and ethyl, and R.sup.3 is selected from hydrogen and methyl; or R.sup.2 and R.sup.3 form together with the carbon atoms to which they are attached C.sub.3-C.sub.5 cycloalkyl; R.sup.4 is selected from C.sub.2-C.sub.5 alkyl, C.sub.2-C.sub.5 alkenyl, C.sub.1-C.sub.4 alkoxy, C.sub.3-C.sub.5 cycloalkyl, and C.sub.3-C.sub.6 cycloalkenyl; or a mixture thereof; and a base material.

2. The fragrance composition according to claim 1 wherein the base material is selected from odorant molecules and auxiliary agents.

3. A fragranced article comprising as odorant a compound of formula (I) ##STR00005## wherein R.sup.1 is selected from hydrogen, methyl and ethyl; R.sup.2 is selected from hydrogen, methyl and ethyl, and R.sup.3 is selected from hydrogen and methyl; or R.sup.2 and R.sup.3 form together with the carbon atoms to which they are attached C.sub.3-C.sub.5 cycloalkyl; R.sup.4 is selected from C.sub.2-C.sub.5 alkyl, C.sub.2-C.sub.5 alkenyl, C.sub.1-C.sub.4 alkoxyl, C.sub.3-C.sub.5 cycloalkyl, and C.sub.3-C.sub.6 cycloalkenyl; 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 fine fragrance, household products, laundry products, body care products, cosmetic products and air care products.

5. The fragranced article according to claim 1, comprising 0.00001 weight % to 90 weight % of the compound of formula (I), or a mixture thereof, based on the total weight of the article.

6. The fragranced article according to claim 3 comprising at least one compound of formula (I), or a mixture thereof, and at least one ingredient selected from the group consisting of a carrier material and fragrance ingredients.

7. A method of Improving, enhancing or modifying a consumer product base comprising adding to the consumer product base an olfactory acceptable amount of a compound of formula (I) ##STR00006## wherein R.sup.1 is selected from hydrogen, methyl and ethyl; R.sup.2 is selected from hydrogen, methyl and ethyl, and R.sup.3 is selected from hydrogen and methyl; or R.sup.2 and R.sup.3 form together with the carbon atoms to which they are attached C.sub.3-C.sub.5 cycloalkyl; R.sup.4 is selected from C.sub.2-C.sub.5 alkyl, C.sub.2-C.sub.5 alkenyl, C.sub.1-C.sub.4 alkoxy, C.sub.3-C.sub.5 cycloalkyl, and C.sub.3-C.sub.6 cycloalkenyl; or a mixture thereof.

8. The method according to claim 7, wherein the consumer product base is selected from the group consisting of fine fragrance, household products, laundry products, body care products, cosmetic products and air care products.

9. A compound of formula (I) ##STR00007## wherein R.sup.1 is selected from methyl and ethyl; R.sup.2 is hydrogen, and R.sup.3 is hydrogen; or R.sup.2 and R.sup.3 form together with the carbon atoms to which they are attached C.sub.3-C.sub.5 cycloalkyl; R.sup.4 is selected from C.sub.3-C.sub.5 alkyl, C.sub.2-C.sub.5 alkenyl, C.sub.3-C.sub.4 alkoxy, C.sub.3-C.sub.5 cycloalkyl, and C.sub.3-C.sub.6 cycloalkenyl with the proviso that R.sup.4 is not isopropyl or tert-butyl.

10. The fragranced article according to claim 3, comprising 0.00001 weight % to 90 weight % of the compound of formula (I), or a mixture thereof, based on the total weight of the article.

11. The fragranced article according to claim 3, wherein the compound of formula (I) is at least one selected from the group consisting of: 3-methyl-6-propyl-2,3-dihydro-1H-Linden-1-one; 6-isobutyl-2,3-dihydro-1H-Inden-1-one; 6-isopropyl-2-methyl-2,3-dihydro-1H-inden-1-one; 6-(tert-butyl)-2-methyl-2,3-dihydro-1H-inden-1-one; 2,3-dimethyl-6-propyl-2,3-dihydro-1H-inden-1-one; 2-methyl-6-propyl-2,3-dihydro-1H-inden-1-one; 6-isobutyl-3-methyl-2,3-dihydro-1H-inden-1-one; 6-isobutyl-2,2-dimethyl-2,3-dihydro-1H-inden-1-one; 6-(tert-butyl)-3-methyl-2,3-dihydro-1H-inden-1-one; 6-cyclopropyl-2-methyl-2,3-dihydro-1H-inden-1-one; 6-cyclopentyl-2-methyl-2,3-dihydro-1H-inden-1-one; 2-ethyl-6-isobutyl-2,3-dihydro-1H-inden-1-one; 6-ethyl-2-methyl-2,3-dihydro-1H-inden-1-one; 6-isopentyl-2-methyl-2,3-dihydro-1H-inden-1-one; 6-ethoxy-2-methyl-2,3-dihydro-1H-inden-1-one; 6-isopropoxy-2-methyl-2,3-dihydro-1H-inden-1-one; 2-methyl-6-propoxy-2,3-dihydro-1H-inden-1-one; 6-isobutoxy-2-methyl-2,3-dihydro-1H-Inden-1-one; 4-isobutyl-6a-methyl-1a,6a-dihydrocyclopropa[a]inden-6(1H)-one; 2-methyl-6-(2-methylallyl)-2,3-dihydro-1H-inden-1-one; and 6-butyl-2-methyl-2,3-dihydro-1H-linden-1-one.

12. The fragrance composition according to claim 1, wherein the compound of formula (I) is at least one selected from the group consisting of: 3-methyl-6-propyl-2,3-dihydro-1H-inden-1-one; 6-isobutyl-2,3-dihydro-1H-inden-1-one; 6-Isopropyl-2-methyl-2,3-dihydro-1H-inden-1-one; 6-(tert-butyl)-2-methyl-2,3-dihydro-1H-inden-1-one; 2,3-dimethyl-6-propyl-2,3-dihydro-1H-inden-1-one; 2-methyl-6-propyl-2,3-dihydro-1H-inden-1-one; 6-isobutyl-3-methyl-2,3-dihydro-1H-inden-1-one; 6-isobutyl-2,2-dimethyl-2,3-dihydro-1H-inden-1-one; 6-(tort-butyl)-3-methyl-2,3-dihydro-1H-inden-1-one; 6-cyclopropyl-2-methyl-2,3-dihydro-1H-inden-1-one; 6-cyclopentyl-2-methyl-2,3-dihydro-1H-inden-1-one; 2-ethyl-6-isobutyl-2,3-dihydro-1H-inden-1-one; 6-ethyl-2-methyl-2,3-dihydro-1H-inden-1-one; 6-isopentyl-2-methyl-2,3-dihydro-1H-Inden-1-one; 6-ethoxy-2-methyl-2,3-dihydro-1H-inden-1-one; 6-isopropoxy-2-methyl-2,3-dihydro-1H-inden-1-one; 2-methyl-6-propoxy-2,3-dihydro-1H-inden-1-one; 6-isobutoxy-2-methyl-2,3-dihydro-1H-inden-1-one; 4-isobutyl-6n-methyl-1a,6a-dihydrocyclopropa[a]inden-6(1H)-one; 2-methyl-6-(2-methylallyl)-2,3-dihydro-1H-Inden-1-one; and 6-butyl-2-methyl-2,3-dihydro-1H-inden-1-one.

13. The method according to claim 7, wherein the compound of formula (I) is at least one selected from the group consisting of: 3-methyl-6-propyl-2,3-dihydro-1H-inden-1-one; 6-isobutyl-2,3-dihydro-1H-inden-1-one; 6-isopropyl-2-methyl-2,3-dihydro-1H-inden-1-one; 6-(tert-butyl)-2-methyl-2,3-dihydro-1H-inden-1-one; 2,3-dimethyl-6-propyl-2,3-dihydro-1H-inden-1-one; 2-methyl-6-propyl-2,3-dihydro-1H-inden-1-one; 6-isobutyl-3-methyl-2,3-dihydro-1H-inden-1-one; 6-isobutyl-2,2-dimethyl-2,3-dihydro-1H-inden-1-one; 6-(tert-buty)-3-methyl-2,3-dihydro-1H-inden-1-one; 6-cyclopropyl-2-methyl-2,3-dihydro-1H-inden-1-one; 6-cyclopentyl-2-methyl-2,3-dihydro-1H-inden-1-one; 2-ethyl-6-isobutyl-2,3-dihydro-1H-inden-1-one; 6-ethyl-2-methyl-2,3-dihydro-1H-inden-1-one; 6-isopentyl-2-methyl-2,3-dihydro-1H-inden-1-one; 6-ethoxy-2-methyl-2,3-dihydro-1H-inden-1-one; 6-isopropoxy-2-methyl-2,3-dihydro-1H-inden-1-one; 2-methyl-6-propoxy-2,3-dihydro-1H-inden-1-one; 6-isobutoxy-2-methyl-2,3-dihydro-1H-inden-1-one; 4-isobutyl-6a-methyl-1a,6a-dihydrocyclopropa[a]inden-6(1H)-one; 2-methyl-6-(2-methylallyl)-2,3-dihydro-1H-inden-1-one; and 6-butyl-2-methyl-2,3-hydro-1H-inden-1-one.

Description

EXAMPLE 1: 6-ISOBUTYL-2-METHYL-2,3-DIHYDRO-1H-INDEN-1-ONE

(1) Procedure A:

(2) To a 100 mL three-necked flask with a magnetic stirrer under argon atmosphere was added phosphonic acid (85% aqueous solution, 31.6 g, 0.274 mol), Phosphorus pentoxide (20.0 g, 0.141 mol) in small portions over 30 min. The mixture was heated to 180° C. and stirred for 30 min before cooled to 80° C. Then 3-(4-isobutylphenyl)-2-methylpropanoic acid (8.00 g, 0.0363 mol) was added and then stirred for 30 min at 80° C. The reaction mixture was cooled to room temperature and poured into 500 mL ice-water with vigorous stirring. The reaction was extracted MTBE (100 mL×2). The combined organic layer was washed successively with water (100 mL×5), saturated aqueous solution of sodium bicarbonate (30.0 mL) and brine (30.0 mL). The organic layer was dried over anhydrous magnesium sulfate. The solvent was removed by rotary evaporation and the crude product was purified by flash chromatography (iso-Hexane/MTBE=20/1) followed by distillation through Kugelrohr (140° C./0.1 mbar) to give 8-isobutyl-2-methyl-2,3-dihydro-1H-inden-1-one (3.93 g, 19.4 mmol, 49% yield) as a colorless liquid.

(3) Procedure B:

(4) To a 500 mL three-necked flask with a magnetic stirrer under argon atmosphere was added 3-(4-isobutylphenyl)-2-methylpropanoic acid (50.0 g, 0.227 mol) in dichloromethane (200 mL). The reaction was cooled to 0° C. SOCl.sub.2 (24.8 mL, 340 mmol) was added dropwise over 20 min. The reaction was heated and refluxed for 2 h. The reaction mixture was cooed to room temperature. Solvent and excessive SOCl.sub.2 was removed through rotary evaporator to give the crude acid chloride which was dissolved in dichloromethane (50 mL) and used in next step without further purification. To another 500 mL three-necked flask with a magnetic stirrer under argon atmosphere was added aluminum trichloride (33.3 g, 250 mmol) in dichloromethane (300 mL). The reaction was cooled to 0° C. The acid chloride solution in dichloromethane above was added dropwise over 30 min. After completion of the addition, the reaction mixture was stirred overnight at room temperature. The reaction was poured into 500 mL ice-water with vigorous stirring. The reaction was extracted with dichloromethane (100 mL×2). The combined organic layer was washed successively with water (150 mL×2), saturated aqueous solution of sodium bicarbonate (100 mL) and brine (50 mL). The organic layer was dried over anhydrous magnesium sulfate. The solvent was removed by rotary evaporation and the crude product was purified by flash chromatography (iso-Hexane/MTBE=20/1) followed by distillation through Kugelrohr (140° C./0.1 mbar) to give 6-isobutyl-2-methyl-2,3-dihydro-1H-inden-1-one (39.0 g, 193 moil, 85% yield) as a colorless liquid.

(5) Procedure C:

(6) In a 100 mL three-necked round-bottomed flask equipped with a condenser and a dropping funnel was added 6-bromo-2-methyl-2,3-dihydro-1H-inden-1-one (0.300 g, 1.33 mmol), isobutylboronic acid (0.272 g, 2.67 mmol), potassium carbonate (0.553 g, 4.00 mmol) and toluene (20 mL) under argon atmosphere. The result solution was stirred and a mixture of palladium (II) acetate (0.015 g, 0.067 mmol) and 1,3-bis(diphenylphosphino) propane (dppp, 0.033 g, 0,080 mmol) in toluene (8 mL) was added. After addition, the reaction solution was heated to reflux for 2 h. The conversion of the reaction was monitored by GC analysis. After completion of the reaction, the mixture was cooled to 10° C. and the reaction solution was poured into water (30 mL). The organic phase was separated and the aqueous layer was extracted with MTBE (30 mL×2). The combined organic layers was washed with brine (20 mL), dried (MgSO.sub.4), and evaporated in vacuo. The crude oil was purified by silica gel chromatography (iso-Hexane/MTBE=50/1) to give 6-isobutyl-2-methyl-2,3-dihydro-1H-inden-1-one (0.189 g, 70% yield) as a colorless liquid.

(7) .sup.1H NMR (300 MHz, CDCl.sub.3): δ=7.53 (s, 1H), 7.27-7.40 (m, 2H), 3.36 (dd, J=18.0, 9.0 Hz, 1H), 2.65-2.74 (m, 2H), 2.52 (d, J=7.2 Hz, 2H), 1.83-1.92 (m, 1H), 1.31 (d, J=7.2 Hz, 3H), 0.90 (d, J=6.6 Hz, 6H) ppm; .sup.13C NMR (75 MHz, CDCl.sub.3): δ=209.7 (s), 151.1 (s), 141.1 (s), 136.4 (s), 136.0 (d), 126.1 (d), 124.0 (d), 44.9 (t), 42.3 (d), 34.6 (t), 30.2 (q), 22.2×2 (q), 16.3 (q) ppm; GC/MS (EI): m/z (%): 202 (55) [M.sup.+], 187 (11), 159 (100), 145 (29), 131 (23), 91 (14) 77 (6).

(8) Odor description: floral fruity fatty, creamy lactonic like, nectaryl-like, rosy, rose petal, green rose oxide-like.

EXAMPLE 2: 3-METHYL-6-PROPYL-2,3-DIHYDRO-1H-INDEN-1-ONE

(9) The title compound was prepared, following the general procedure A as described in Example 1. Starting from 3-(4-propylphenyl)butanoic acid (5.28 g, 25.6 mml) followed m by distillation through Kugelrohr (140° C./0.10 mbar) to give 3-methyl-6-propyl-2,3-dihydro-1H-inden-1-one as a colorless oil (2.50 g, 61% yield).

(10) Odor description: green, floral, minty, jasmone, jasmine, camonal.

(11) .sup.1H NMR (300 MHz, CDCl.sub.3): δ=7.54 (s, 1H), 7.39-7.46 (m, 2H), 3.37-3.43 (m, 1H), 2.94 (dd, J=18.9, 72 Hz, 1H), 2.64 (t, J=7.6 Hz, 2H), 2.27 (dd, J=18.9, 3.3 Hz, 1H), 1.59-1.72 (m, 2H), 1.39 (d, J=72 Hz, 3H), 0.93 (f, J=7.2 Hz, 3H) ppm; .sup.13C NMR (75 MHz, CDCl.sub.6): δ=206.6 (s), 157.7 (s), 142.2 (s), 136.6 (s), 135.6 (d), 125.0 (d), 122.8 (d), 45.7 (t), 37.5 (t), 32.5 (d), 24.4 (t), 21.4 (q), 13.7 (q) ppm; GC/MS (EI): m/z (%): 188 (70) [M.sup.+], 173 (73), 159 (100), 145 (20), 131 (31), 115 (28), 91 (12).

EXAMPLE 3: 6-ISOBUTYL-2,3-DIHYDRO-1H-INDEN-1-ONE

(12) The title compound was prepared, following the general procedure A as described in Example 1. Starting from of 3-(4-isobutylphenyl)propanoic acid (45.0 g, 218 mmol) followed by distillation through Kugelrohr (140° C./0.14 mbar) to give 6-isobutyl-2,3-dihydro-1H-inden-1-one as a colorless oil (22.0 g, 54% yield).

(13) Odor description: green floral, isobutyl benzoate.

(14) .sup.1H NMR (300 MHz, CDCl.sub.3): δ=7.53 (s, 1H), 7.35-7.41 (m, 2H), 3.10 (t, J=6.0 Hz, 2H), 2.70 (t, J=6.0 Hz, 2H), 2.53 (d, J=7.2 Hz, 2H), 1.80-1.92 (m, 1H), 0.90 (d, J=6.6 Hz, 6H) ppm; .sup.13C NMR (75 MHz, CDCl.sub.3): δ=207.3 (s), 152.9 (s), 141.1 (s), 137.1 (s), 135.9 (d), 126.2 (d), 123.7 (d), 44.9 (t), 36.6 (t), 30.2 (d), 25.4 (t), 22.2×2 (q) ppm: GC/MS (EI): m/z (%): 188 (60) [M.sup.+], 173 (1), 146 (100), 115 (34), 104 (26), 91 (16), 77 (5).

EXAMPLE 4: 6-ISOPROPYL-2-METHYL-2,3-DIHYDRO-1H-INDEN-1-ONE

(15) The title compound was prepared, following the general procedure A as described in Example 1. Starting from of 3-(4-isopropylphenyl)-2-methylpropanoic acid (10.0 g, 48.5 mmol) followed by distillation through Kugelrohr (140° C./0.10 mbar) to give 6-isopropyl-2-methyl-2,3-dihydro-1H-inden-1-one as a colorless oil (6.80 g, 74% yield).

(16) Odor description: green fatty, lactonic fruity, rosy metallic.

(17) .sup.1H NMR (300 MHz, CDCl.sub.6): δ=7.63 (s, 1H), 7.46-7.49 (m, 1H), 7.37 (d, J=7.8 Hz 1H), 3.32-4.40 (m, 1H), 2.93-4.02 (m, 1H), 2.65-2.75 (m, 2H), 1.31 (d, J=7.2 Hz, 3H), 1.27 (d, J=8.9 Hz, 6H) ppm; .sup.13C NMR (75 MHz, CDCl.sub.6): δ=209.7 (s), 151.3 (s), 148.5 (s), 136.5 (s), 133.8 (d), 126.4 (d), 121.2 (d), 42.4 (d), 34.6 (t), 33.9 (d), 24.0×2 (q), 16.4 (q) ppm; GC/MS (EI): m/z (%): 188 (43) [M.sup.+], 173 (100), 145 (17), 117 (26), 91 (10), 77 (4)

EXAMPLE 5: 6-(TERT-BUTYL)-2-METHYL-2,3-DIHYDRO-1H-INDEN-1-ONE

(18) The title compound was prepared, following the general procedure A as described in Example 1. Starting from 3-(4-(tert-butyl)phenyl)-2-methylpropenoic acid (10.0 g, 45.4 mmol) followed by distillation through Kugelrohr (140° C./0.14 mbar) to give 6-(tert-butyl)-methyl-2,3-dihydro-1H-inden-1-one as a colorless oil (7.50 g, 82% yield).

(19) Odor description: green fatty, lactonic fruity, slightly fatty cinnamic.

(20) .sup.1H NMR (300 MHz, CDCl.sub.3): δ=7.78 (s, 1H), 7.65-7.68 (m, 1H), 7.39 (d, J=7.8 Hz, 1H), 3.32-3.40 (m, 1H), 2.65-2.75 (m, 2H), 1.34 (s, 9H), 1.31 (d, J=7.5 Hz, 3H) ppm, .sup.13C NMR (75 MHz, CDCl.sub.3): δ=209.8 (s), 150.9 (s), 150.9 (s), 136.3 (s), 132.5 (d), 126.1 (d), 120.3 (d), 42.4 (d), 34.8 (s), 34.5 (t), 31.4×3 (q), 16.4 (q) ppm; GC/MS (EI): m/z (%): 202 (23) [M.sup.+], 187 (100), 159 (15), 131 (19), 115 (10), 91 (6), 77 (2).

EXAMPLE 6: 2,3-DIMETHYL-6-PROPYL-2,3-DIHYDRO-1H-INDEN-1-ONE

(21) The title compound was prepared, following the general procedure A as described in Example 1. Starting from 2-methyl-3-(4-propylphenyl)butanoic acid (8.00 g, 36.3 mmol) followed by distillation through Kugelrohr (140° C./0.10 mbar) to give 2,3-dimethyl-6-propyl-2,3-dihydro-1H-inden-1-one as a colorless oil (1.50 g, 20% yield).

(22) Odor description: green fatty oily, fatty fruity lactonic, metallic rosy.

(23) .sup.1H NMR (300 MHz, CDCl.sub.3): δ=7.54 (s, 1H), 7.28-7.486 (m, 2H), 2.85-2.94 (m, 1H), 2.64 (t, J=7.5 Hz, 2H), 2.19-2.74 (m, 1H), 1.59-1.71 (m, 2H), 1.44 (d, J=7.2 Hz, 3H), 1.31 (d, J=7.5 Hz, 3H), 0.94 (t, J=7.5 Hz, 3H) ppm; .sup.13C NMR (75 MHz, CDCl.sub.3): δ=208.6 (s), 155.5 (s), 142.2 (s), 136.0 (s), 135.5 (d), 124.6 (d), 122.9 (d), 51.8 (d), 41.4 (d), 37.6 (t), 24.5 (t), 19.2 (q), 14.2 (q) 13.7 (q) ppm; GC/MS (EI): m/z (%): 202 (40) [M.sup.+], 187 (100), 173 (24), 145 (14), 115 (15), 91(8), 77 (3).

EXAMPLE 7: 2-METHYL-6-PROPYL-2,3-DIHYDRO-1H-INDEN-1-ONE

(24) The title compound was prepared, following the general procedure A as described in Example 1. Starting from 2-methyl-3-(4-propylphenyl)propanoic acid (6.00 g, 29.1 mmol) followed by distillation through Kugelrohr (160° C./0.20 mbar) to give 2-methyl-6-propyl-2,3-dihydro-1H-inden-1-one as a colorless oil (3.50 g, 64% yield).

(25) Odor description: green, floral, fatty, rosy cinnamic.

(26) .sup.1H NMR (300 MHz, CDCl.sub.3): δ=7.57 (s, 1H) 7.34-7.43 (m, 2H), 3.36 (dd, J=18.0, 9.0 Hz, 1H), 2.81-2.74 (m, 4H), 1.69-1.71 (m, 2H), 1.30 (d, J=7.2 Hz, 3H), 0.93 (t, J=7.2 Hz, 3H) ppm; .sup.13C NMR (75 MHz, CDCl.sub.3): δ=209.7 (s), 151.1 (s), 142.1 (s), 136.5 (s), 135.5 (d), 126.2 (d), 123.3 (d), 42.3 (d), 37.8 (t), 34.6 (t), 24.5 (t), 16.3 (q), 13.7 (q) ppm: GC/MS (EI): m/z (%): 188 (62) [M.sup.+], 173 (70) 159 (100), 145 (19), 131 (31), 91 (16), 77 (7).

EXAMPLE 8: 6-ISOBUTYL-3-METHYL-2,3-DIHYDRO-1H-INDEN-1-ONE

(27) The title compound was prepared, following the general procedure B as described in Example 1. Starting from 3-(4-isobutylphenyl)butanoic acid (25.0 g, 113 mmol) followed by distillation through Kugelrohr (150° C./0.10 mbar) to give 6-isobutyl-3-methyl-2,3-dihydro-1H-inden-1-one as a colorless oil (15.0 g, 65% yield).

(28) Odor description: green rosy, fatty, metallic rosy, fatty fruity floral.

(29) .sup.1H NMR (300 MHz, CDCl.sub.3) δ=7.50 (s, 1H), 7.41 (s, 2H), 3.37-3.43 (m, 1H), 2.93 (dd, J=19.2, 7.5 Hz, 1H), 2.53 (d, J=7.2 Hz, 2H), 2.27 (dd, J=18.9, 27 Hz, 1H), 1.80-1.94 (m, 1H), 1.39 (d, J=72 Hz, 3H), 0.90 (d, J=6.6 Hz, 6H) ppm; .sup.13C NMR (75 MHz, CDCl.sub.3): δ=206.7 (s), 157.7 (s), 141.2 (s), 136.4 (s), 136.1 (d), 124.9 (d), 123.4 (d), 45.7 (t), 44.9 (t), 32.5 (d), 30.2 (d), 222×2 (q), 21.4 (q) ppm; GC/MS (EI): m/z (%): 202 (65) [M.sup.+], 187 (11), 159 (100), 145 (27), 131 (22), 115 (29), 91 (13), 77 (4).

EXAMPLE 9: 6-ISOBUTYL-2,2-DIMETHYL-2,3-DIHYDRO-1H-INDEN-1-ONE

(30) The title compound was prepared, following the general procedure A as described in Example 1. Starting from 3-(4-isobutylphenyl)-2,2-dimethylpropanoic acid (5.36 g, 22.9 mmol) followed by distillation through Kugeltrohr (150° C./0.10 mbar) to give 6-isobutyl-2,2-dimethyl-2,3-dihydro-1H-inden-1-one as a colorless oil (3.50 g, 71% yield).

(31) Odor description: floral fatty, fruity, green, rubbery, muguet.

(32) .sup.1H NMR (300 MHz, CDCl.sub.3): δ=7.54 (s, 1H), 7.31-7.40 (m, 2H), 2.96 (s, 2H), 2.52 (d, J=7.2 Hz, 2H), 1.83-1.92 (m, 1H), 1.23 (s, 6H), 0.90 (d, J=6.6 Hz, H) ppm; .sup.13C NMR (75 MHz, CDCl.sub.3): δ=211.6 (s), 149.8 (s), 141.2 (s), 136.2 (d), 135.3 (s), 126.2 (d), 124.4 (d), 45.8 (s), 45.0 (t), 42.5 (t), 30.2 (d), 253×2 (q), 22.3×2 (q) ppm; GC/MS (EI): m/z (%): 216 (59) [M.sup.+], 201 (100), 173 (87), 159 (21), 115 (17).

EXAMPLE 10: 6-(TERT-BUTYL)-3-METHYL-2,3-DIHYDRO-1H-INDEN-1-ONE

(33) The title compound was prepared, following the general procedure B as described in Example 1. Starting from 3-(4-(tert-buty)phenyl)butanoic acid (4.43 g, 20.1 mmol) followed by distillation through Kugelrohr (150° C./0.10 mbar) to give 6-(tert-buty)-3-methyl-2,3-dihydro-1H-inden-1-one as a colorless oil (2.60 g, 64% yield).

(34) Odor description: fruity, floral.

(35) .sup.1H NMR (300 MHz, CDCl.sub.3): δ=7.75 (d, J=1.8 Hz, 1H), 7.68 (dd, J=8.1, 1.8 Hz, 1H), 7.44 (d, J=8.1 Hz, 1H), 3.36-3.42 (m, 1H), 2.93 (dd, J=18.9, 7.5 Hz, 1H), 2.26 (dd, J=18.9, 3.3 Hz, 1H), 1.39 (d, J=6.6 Hz, 3H), 1.34 (s, 9H) ppm; .sup.13C NMR (75 MHz, CDCl.sub.3): δ=206.6 (s), 157.4 (s), 150.8 (s), 136.3 (s), 132.5 (d), 124.9 (d) 119.6 (d), 46.7 (t), 34.7 (s), 32.3 (d), 31.3×3 (q), 21.3 (q) ppm; GC/MS (EI): m/z (%): 202 (22) [M.sup.+], 187 (100), 159 (19), 145 (21), 91 (6), 77 (4).

EXAMPLE 11: 6-CYCLOPROPYL-2-METHYL-2,3-DIHYDRO-1H-INDEN-1-ONE

(36) The title compound was prepared, following the general procedure C as described in Example 1. 6-Bromo-2-methyl-2,3-dihydro-1H-inden-1-one (1.50 g, 6.66 mmol), cyclopropylboronic acid (1.15 g, 13.33 mmol), potassium carbonate (2.76 g, 20.0 mmol), palladium (II) acetate (0.075 g, 0.333 mmol) and 1,1-bis(diphenyphosphino)ferrocene (dppf ligand; 0.222 g, 0.400 mmol) in toluene (30 mL) were reacted at reflux under argon atmosphere for 2 h followed by distillation through Kugelrohr (135° C./0.10 mbar) to give 6-cyclopropyl-2-methyl-2,3-dihydro-1H-inden-1-one as a colorless liquid (1.00 g, 81% yield).

(37) Odor description: green, fatty, floral, rosy metallic.

(38) .sup.1H NMR (300 MHz, CDCl.sub.3): δ=7.39 (s, 1H), 7.29-7.36 (m, 2H), 3.33 (dd, J=17.7, 5.7 Hz, 1H) 2.61-2.71 (m, 2H), 1.88-1.97 (m, 1H), 1.28 (d, J=7.2 Hz, 3H), 0.95-1.01 (m, 2H), 0.68-0.73 (m, 2H) ppm: .sup.13C NMR (75 MHz, CDCl.sub.3) δ=209.5 (s), 150.8 (s), 143.7 (s), 136.4 (s), 133.2 (d), 1262 (d), 119.9 (d), 42.3 (d), 34.5 (t), 16.3 (q), 15.1 (d), 9.5×2 (t) ppm; GC/MS (EI): m/z (%): 186 (72) [M.sup.+], 171 (100), 158 (16), 143 (30), 128 (42), 115 (45), 91 (10).

EXAMPLE 12: 6-CYCLOPENTYL-2-METHYL-2,3-DIHYDRO-1H-INDEN-1-ONE

(39) The title compound was prepared, following the general procedure C as described in Example 1. 68-Bromo-2-methyl-2,3-dihydro-1H-inden-1-one (2.00 g, 8.89 mmol), cyclopentylboronic acid (2.03 g, 17.8 mmol), potassium carbonate (3.68 g, 25.7 mmol), palladium (II) acetate (0.080 g, 0,355 mmol) and 1,1′-bis(diphenylphosphino)ferrocene (dppf ligand: 0.246 g, 0.444 mmol) in toluene (20 ml) were reacted at reflux under argon atmosphere for 2 h followed by distillation through Kugelrohr (140° C./0.15 mbar) to give 6-cyclopentyl-2-methyl-2,3-dihydro-1H-inden-1-one as a colorless liquid (0.50 g, 26% yield).

(40) Odor description: fruity fatty floral, peachy, green rosy.

(41) .sup.1H NMR (300 MHz, CDCl.sub.3): δ=7.63 (s, 1H), 7.48 (d, J=7.8 Hz, 1H), 7.35 (d, J=7.8 Hz, 1H), 3.35 (dd, J=18.0, 9.0 Hz, 1H), 2.98-3.10 (m, 1H), 2.64-2.73 (m, 2H), 2.07-2.09 (m, 2H), 1.58-1.81 (m, 6H), 1.30 (d, J=7.5 Hz, 3H) ppm; .sup.13C NMR (75 MHz, CDCl.sub.3): δ=209.7 (s), 151.2 (s), 148.2 (s), 136.4 (s), 134.4 (d), 126.2 (d), 121.8 (d), 45.8 (d), 42.4 (d), 34.7×2 (t), 34.6 (t), 25.5×2 (t), 18.4 (q) ppm; GC/MS (EI): m/z (%): 214 (100) [M.sup.+], 199 (55), 186 (39), 172 (61), 157 (47), 143 (32), 129 (59)<115 (40).

EXAMPLE 13: 2-ETHYL-6-ISOBUTYL-2,3-DIHYDRO-1H-INDEN-1-ONE

(42) To a solution of (E)-2-(4-isobutylbenzylidene)butanal (5.35 g, 24.7 mmol) in toluene (50 mL) was added methanesulfonamide (2.82 g, 29.7 mmol) and iron(III) chloride (0.80 g, 4.9 mmol). The mixture was stirred and heated to 65′C for 16 h. After the aldehyde was completely consumed (monitored by GC) the reaction was cooled to room temperature. Then methanol (30 mL) and a solution of sodium hydroxide (2.47 g, 61.8 mmol) in water (20 mL) was added. The mixture was stirred for 2 h at room temperature. The resulting mixture was then treated with methanol (30 ml) and dropwise with 37% hydrogen chloride (626 ml, 74.2 mmol), heated to 70° C. and stirred overnight. After cooling, water (200 ml) was added and the solution was extracted with MTBE (100.3 mL). The combined organic layers were washed with brine, dried with MgSO.sub.4, filtered and concentrated to give the crude product. The residue was purified by silica gel chromatography (hexane:MTBE=50:1) followed by distillation through Kugelrohr (160° C./0.15 mbar) to give 2-ethyl-6-isobutyl-2,3-dihydro-1H-inden-1-one as colorless oil (2.60 g, 49% yield).

(43) Odor description: floral fatty green, oily cinnamic, nectaryl

(44) .sup.1H NMR (300 MHz, CDCl.sub.3): δ=7.52 (s, 1H), 7.34-7.40 (m, 2H), 3.28 (dd, J=17.1, 7.8 Hz, 1H), 2.78 (dd, J=17.1, 3.9 Hz, 1H), 2.58-2.65 (m, 1H), 2.52 (d, J J=7.2 Hz, 2H), 1.80-2.04 (m, 2H), 1.46-1.60 (m, 1H), 1.01 (t, J=7.5 Hz, 3H), 0.90 (d, J=6.6 Hz, 6H) ppm: .sup.13C NMR (75 MHz, CDCl.sub.3): δ=209.2 (s), 151.5 (s), 141.1 (s), 137.0 (s), 136.0 (d), 126.1 (d), 123.8 (d), 49.2 (d), 44.9 (t), 32.0 (t), 30.2 (d), 24.5 (t), 22.3×2 (q), 11.7 (q) ppm: GC/MS (EI): m/z (%): 216 (7) [M.sup.+], 188 (100), 173 (33), 145 (36), 131 (20), 91 (7), 77 (7).

EXAMPLE 14: 6-ETHYL-2-METHYL-2,3-DIHYDRO-1H-INDEN-1-ONE

(45) The title compound was prepared, following the general procedure described in Example 13, starting from (E)-3-(4-ethylphenyl-2-methylacrylaldehyde (5.0 g, 28.7 mmol), methanesulfonamide (4.09 g, 43.0 mmol) and iron(III) chloride (0.931 g, 5.74 mmol) followed by distillation through Kugelrohr (150° C./0.12 mbar) to give 6-ethyl-2-methyl-2,3-dihydro-1H-inden-1-one as a colorless oil (1.30 g, 26% yield).

(46) Odor description: green minty floral, carvone jasmine fruity.

(47) .sup.1H NMR (300 MHz, CDCl.sub.3): δ=7.58 (s, 1H), 7.34-7.44 (m, 2H), 3.35 (dd, J=18.0, 8.7 Hz, 1H), 2.65-2.73 (m, 4H), 1.22-1.31 (m, 6H) ppm; .sup.13C NMR (75 MHz, CDCl.sub.3): δ=209.6 (s), 151.1 (s), 143.7 (s), 136.5 (s), 135.0 (d), 126.3 (d), 122.8 (d), 42.3 (d), 34.6 (t), 28.5 (t), 16.3 (q), 15.6 (q) ppm; GC/MS (EI): m/z (%): 174 (60) [M.sup.+], 159 (100), 145 (23), 131 (32), 115 (22), 91 (13), 77 (7).

EXAMPLE 15: 6-(SEC-BUTYL)-2-METHYL-2,3-DIHYDRO-1H-INDEN-1-ONE

(48) The title compound was prepared, following the general procedure as described in Example 13. Starting from (E)-3-(4-(sec-buty)phenyl)-2-methylacrylaldehyde (5.00 g, 14.8 mmol), methanesulfonamide (1.89 g, 17.8 mmol) and iron(III) chloride (0.481 g, 2.97 mmol) followed by distillation through Kugelrohr (150° C./0.08 mbar) to give 6-ethyl-2-methyl-2,3-dihydro-1H-inden-1-one as a colorless oil (1.00 g, 33% yield).

(49) Odor description: green rosy metallic, green leathery, fatty floral.

(50) (mixture of two isomers in a ratio of 1:1) .sup.1H NMR (300 MHz, CDCl.sub.3): δ=7.59 (s, 1H), 7.38-7.44 (m, 2H), 3.32-3.41 (m, 1H), 2.66-2.73 (m, 3H), 1.58-1.63 (m, 2H), 1.31 (d, J=7.2 Hz, 3H), 1.25 (d, J=6.9 Hz, 3H), 0.81 (t, J=7.2 Hz, 3H) ppm; .sup.13C NMR (75 MHz, CDCl.sub.3): δ=209.8 (s), 151.3 (s), 147.2 (s), 138.5 (s), 134.4 (d), 134.3 (d), 126.3 (d), 121.9 (d), 121.9 (d), 42.4 (d), 41.4 (d), 34.6 (t), 31.1 (t), 21.9 (q), 16.3 (q), 12.2 (q) ppm; GC/MS (EI): m/z (%): 202 (30) [M.sup.+], 187 (5), 173 (100), 159 (7), 117 (27), 91 (8), 77 (4)

EXAMPLE 16: 6-ISOPENTYL-2-METHYL-2,3-DIHYDRO-1H-INDEN-1-ONE

(51) The title compound was prepared, following the general procedure as described in Example 13. Starting from (E)-3-(4-isopentylphenyl)-2-methylacrylaldehyde (5.00 g, 18.5 mmol), methanesulfonamide (2.11 g, 222 mmol) and iron(III) chloride (0.600 g, 3.70 mmol) followed by distillation through Kugelrohr (162° C./0.10 mbar) to give 6-isopentyl-2-methyl-2,3-dihydro-1H-inden-1-one as a colorless oil (1.30 g, 33% yield).

(52) Odor description: green rosy, fatty lactonic, rosy powdery, cinnamate like.

(53) .sup.1H NMR (300 MHz, CDCl.sub.3): δ=7.57 (s, 1H), 7.32-7.42 (m, 2H), 3.34 (dd, J=18.0, 8.7 Hz, 1H), 2.62-2.70 (m, 4H), 1.46-1.62 (m, 3H), 1.29 (d, J=7.2 Hz, 3H), 0.93 (d, J=6.9 Hz, 6H) ppm; .sup.13C NMR (75 MHz, CDCl.sub.3): δ=209.5 (s), 151.0 (s), 142.5 (s), 136.5 (s), 135.4 (d), 126.3 (d), 123.1 (d) 42.3 (d), 40.8 (t), 34.6 (t), 33.3 (t), 27.5 (d), 22.5×2 (q), 16.3 (q) ppm; GC/MS (EI): m/z (%): 216 (80) [M.sup.+], 201 (30), 187 (1), 159 (98), 132 (100), 118 (55), 104 (55), 91(23), 77 (8).

EXAMPLE 17: 6-ETHOXY-2-METHYL-2,3-DIHYDRO-1H-INDEN-1-ONE

(54) To a solution of 6-hydroxy-2-methyl-2,3-dihydro-1H-inden-1-one (2.00 g, 12.3 mmol) in N,N-Dimethylformamide (30 mL), iodoethane (2.50 g, 16.0 mmol) and potassium carbonate (1.87 g, 13.5 mmol) were added at room temperature. The mixture was heated for 6 h at 55° C. under argon atmosphere. The reaction was cooled to room temperature, quenched with water (60 mL) and extracted with MTE (30 mL×3). The combined organic layer was dried over MgSO.sub.4, filtrated end concentrated. The residue was purified by chromatography on silica gel (iso-Hexane/MTBE=9/1) followed by distillation via Kugelrohr (145° C./010 mbar) to give 6-ethoxy-2-methyl-2,3-dihydro-1H-inden-1-one as a white powder (2.00 g, 85% yield).

(55) Odor description: green, waxy fruity, rosy.

(56) .sup.1H NMR (300 MHz, CDCl.sub.3): δ=7.33 (d, J=9.0 Hz, 1H), 7.16-7.19 (m, 2H), 4.06 (q, J=6.9 Hz, 2H), 3.32 (dd, J=16.5, 7.5 Hz, 1H), 2.70-2.76 (m, 1H), 2.64 (dd, J=16.5, 3.6 Hz, 1H), 1.42 (t, J=6.9 Hz, 3H), 1.31 (d, J=7.5 Hz, 3H) ppm; .sup.13C NMR (75 MHz, CDCl.sub.2): δ=209.5 (s), 158.7 (s), 146.1 (s), 137.4 (s), 127.2 (d), 124.5 (d), 105.8 (d), 63.8 (t), 42.8 (d), 34.3 (t), 16.4 (q), 14.7 (q) ppm; GC/MS (EI): m/z (%): 190 (80) [M.sup.+], 175 (35), 162 (16), 147 (100), 133 (35), 119 (11), 105 (10).

EXAMPLE 18: 6-ISOPROPOXY-2-METHYL-2,3-DIHYDRO-1H-INDEN-1-ONE

(57) The title compound was prepared, following the general as described in Example 17. 6-Hydroxy-2-methyl-2,3-dihydro-1H-inden-1-one (1.00 g, 6.17 mmol), 2-bromopropane (3.41 g, 27.7 mmol) and potassium carbonate (2.81 g, 20.3 mmol) in dimethylformamide (DMF; 30 m) were reacted at 55° C. under argon for 6 h to give 6-isopropoxy-2-methyl-2,3-dihydro-1-inden-1-one as a colorless liquid (0.90 g, 72% yield).

(58) Odor description: green rosy fatty floral, slightly fatty fruity, metallic rosy

(59) .sup.1H NMR (300 MHz, CDCl.sub.3): =7.31-7.40 (m, 1H), 7.13-7.18 (m, 2H), 4.58-4.60 (m, 1H), 3.31 (dd, J=16.5, 7.5 Hz, 1H), 2.60-2.76 (m, 2H), 1.34 (d, J=6.0 Hz, 6H), 1.30 (d, J=7.2 Hz, 3H) ppm: .sup.13C NMR (75 MHz, CDCl.sub.3): δ=209.5 (s), 157.6 (s), 145.9 (s), 137.4 (s), 127.3 (d), 125.6 (d), 107.3 (d), 70.2 (d), 42.8 (d), 34.2 (t), 21.9 (q), 21.9 (q), 16.4 (q) ppm; GC/MS (E): m/z (%): 204 (33) [M.sup.+], 189 (1), 162 (50), 147 (100), 105 (7), 91 (5), 77 (8)

EXAMPLE 19: 2-METHYL-6-PROPOXY-2,3-DIHYDRO-1H-INDEN-1-ONE

(60) The title compound was prepared, following the general as described in Example 17. 6-Hydroxy-2-methyl-2,3-dihydro-1H-inden-1-one (2.00 g, 12.3 mmol), 1-bromo-2-methylpropane (7.60 g, 55.5 mmol) and potassium carbonate (2.36 g, 17.3 mmol) in acetone (30 mL) were refluxed under argon atmosphere for 6 h to give 2-methyl-6-propoxy-2,3-dihydro-1H-inden-1-one as a white powder (1.30 g, 52% yield).

(61) Odor description: waxy, fatty fruity, green floral.

(62) .sup.1H NMR (300 MHz, CDCl.sub.3): δ=7.32 (d, J=9.0 Hz, 1H), 7.17-7.20 (m, 2H), 3.94 (t, J=6.3 Hz, 2H), 3.32 (dd, J=16.5, 7.5 Hz, 1H), 2.70-2.78 (m, 1H), 2.84 (dd, J=16.5, 3.9 Hz, 1H), 1.76-1.87 (m, 2H), 1.30 (d, J=7.5 Hz, 3H), 1.04 (t, J=7.6 Hz, 34) ppm; .sup.13C NMR (75 MHz, CDCl.sub.3): δ=209.5 (s), 158.9 (s), 146.0 (s), 137.4 (s), 127.2 (d), 124.5 (d), 105.9 (d), 69.9 (t), 42.8 (d), 34.3 (t), 22.4 (t), 16.4 (q), 10.5 (q) ppm; GC/MS (EI): m/z (%): 204 (52) [M.sup.+], 189 (1), 162 (42), 147 (100), 134 (25), 115 (10), 91 (10).

EXAMPLE 20: 6-ISOBUTOXY-2-METHYL-2,3-DIHYDRO-1H-INDEN-1-ONE

(63) The title compound was prepared, following the general as described in Example 17, 6-Hydroxy-2-methyl-2,3-dihydro-1H-inden-1-one (2.00 g, 12.3 mmol), 1-bromo-2-methylpropane (7.60 g, 55.5 mmol) and potassium carbonate (5.62 g, 40.7 mmol) in DMF (30 mL) were reacted at 55° C. under argon atmosphere for 6 h to give 6-isobutoxy-2-methyl-2,3-dihydro-1H-inden-1-one (1.90 g, 71% yield) as a colorless liquid.

(64) Odor description: floral fruity fatty, green anisic.

(65) .sup.1H NMR (300 MHz, CDCl.sub.3): δ=7.33 (d, J=8.1 Hz, 1H), 7.17-7.21 (m, 2H), 3.75 (d, J=6.6 Hz, 2H), 3.32 (dd, J=16.5, 7.5 Hz, 1H), 2.70-2.79 (m, 1H), 2.64 (dd, J=16.5, 3.6 Hz, 1H), 2.02-2.16 (m, 1H), 1.31 (d, J=7.2 Hz, 3H), 1.02 (d, J=6.6 Hz, 6H) ppm; .sup.13C NMR (75 MHz, CDCl.sub.3): δ=209.5 (s), 159.0 (s), 148.0 (s), 137.4 (s), 127.2 (d), 124.5 (d), 105.9 (d), 74.8 (t), 42.8 (d), 34.3 (t), 28.1 (d), 19.2×2 (q), 16.4 (q) ppm; GC/MS (EI): m/z (%): 218 (41) [M.sup.+], 203 (1), 162 (70), 147 (100), 134 (28), 115 (11), 91 (8).

EXAMPLE 21: 4-ISOBUTYL-6A-METHYL-1A,6A-DIHYDROCYCLOPROPA[A]INDEN-6(1H)-ONE

(66) In a 250 mL three-necked round-bottomed flask was added 4-isobutyl-6a-methyl-1,1a,6,6a-tetrahydrocyclopropa[a]inden-6-ol (0.40 g, 1.85 mmol) in dichloromethane (50 mL) to give a colorless solution, pyridinium chlorochromate (1.00 g, 4.62 mmol) was added. The reaction mixture was stirred at room temperature for 2 h until completion of the conversion. The reaction was diluted by iso-hexane (100 ml) and then filtered through a small pad of silica gel. The silica gel was rinsed with dichloromethane and iso-hexane. The combined filtrate was concentrated to give a yellow residue which was further purified by column chromatography (iso-Hexane/MTBE=20/1) to give 4-isobutyl-6a-methyl-1a,6a-dihydrocyclopropa[a]inden-6(1H)-one (60 mg, 15% yield) as a tight yellow liquid.

(67) Odor description: fatty, fruity, green, floral, with some rubbery facets.

(68) .sup.1H NMR (300 MHz, CDCl.sub.3): δ=7.34 (s, 1H), 7.12-7.21 (m, 2H), 2.58-2.61 (m, 1H), 2.38 (d, J=6.9 Hz, 2H), 1.70-1.79 (m, 1H), 1.44 (s, 3H), 1.29-1.31 (m, 2H), 0.79 (d, J=6.9 Hz, 6H) ppm; .sup.13C NMR (75 MHz, CDCl.sub.3): δ=205.0 (s), 152.2 (s) 140.4 (s), 134.6 (d), 133.6 (s) 125.0 (d), 123.7 (d), 44.9 (t), 39.8 (t), 33.1 (s), 30.2 (d), 28.2 (d) 22.2×2 (q), 13.6 (q) ppm; GC/MS (EI): m/z (%): 214 (37) [M.sup.+], 199 (2), 171 (100), 158 (18), 128 (40), 115 (13).

EXAMPLE 22: 2-METHYL-6-(2-METHYLALLYL)-2,3-DIHYDRO-1H-INDEN-1-ONE

(69) Cesium carbonate (3.26 g, 10.0 mmol) was placed in 100 mL three-necked reaction flask equipped with a condenser. Palladium (II) acetate (0.075 g, 0.333 mmol) and triphenylphosphine (0.35 g, 1.33 mmd) were added in the reaction flask. The flask was then filled with argon. Toluene (35 mL), 3-isopropyl-2,5-dimethylhex-5-en-3-ol (1.36 g, 8.00 mmol) and 6-bromo-2-methyl-2,3-dihydro-1H-indenone (1.50 g, 6.66 mmol) were sequentially added at room temperature. The resulting mixture was heated at reflux for 2 h. After the mixture was cooled to room temperature, it was filtered through a short silica gel pad, and washed with MTBE (100 mL). Remove the solvent by rotary evaporate, and the residue was purified by silica gel chromatography (iso-Hexane/MTBE=50/1) to give 2-methyl-6-(2-methylallyl)-2,3-dihydro-1H-inden-1-one (1.20 g, 90% yield) as alight yellow oi.

(70) Odor description: fatty, fruity, green, floral, cinnamic cinnamate like.

(71) .sup.1H NMR (300 MHz, CDCl.sub.3): δ=7.58 (s, 1H), 7.36-7.45 (m, 2H), 4.83 (s, 1H), 4.74 (s, 1H), 3.36 (s, 2H), 3.32-3.41 (m, 1H), 2.66-2.75 (m, 2), 1.66 (s, 3H), 1.31 (d, J=7.2 Hz, 3H) ppm; .sup.13C NMR (75 MHz, CDCl.sub.3): δ=209.6 (s), 151.6 (s) 144.4 (s), 139.3 (s), 136.6 (s), 135.7 (d), 126.3 (d), 124.0 (d), 112.5 (t), 44.2 (t), 42.4 (d), 34.7 (t), 22.0 (q), 16.3 (q) ppm; GC/MS (EI): m/z (%): 200 (29) [M.sup.+], 185 (100), 172 (57), 157 (75), 144 (73), 129 (85), 115 (60).

EXAMPLE 23: 6-BUTYL-2-METHYL-2,3-DIHYDRO-1H-INDEN-1-ONE

(72) The title compound was prepared, following the general procedure C as described in Example 1. 6-Bromo-2-methyl-2,3-dihydro-1H-inden-1-one (4.00 g, 17.8 mmol), butylboronic acid (3.62 g, 35.5 mmol), potassium carbonate (3.68 g, 26.7 mmol), palladium (II) acetate (0.160 g, 0.711 mmol) and 1,1′-bis(diphenylphosphino)ferrocene (dppf ligand; 0.394 g, 0.711 mmol) in toluene (30 mL) were reacted at reflux under argon atmosphere for 2 h followed by distillation through Kugelrohr (145° C./0.10 mbar) to give 6-butyl-2-methyl-2,3-dihydro-1H-inden-1-one as a colorless liquid (0.67 g, 18% yield).

(73) Odor description green fatty floral: rosy, peach, green rubbery slightly leathery isobutyl salicylate

(74) .sup.1H NMR (300 MHz, CDCl.sub.3): δ=7.57 (s, 1H), 7.42 (d, J=7.1 Hz, 1H), 7.35 (d, J=7.1 Hz, 1H), 3.36 (dd, J=18.0, 9.0 Hz, 1H), 2.64-2.74 (m, 4H), 1.56-1.66 (m, 2H), 1.26-1.38 (m, 5H), 0.92 (t, J=7.5 Hz, 3H) ppm. .sup.13C NMR (75 MHz, CDCl.sub.3): δ=209.7 (s), 151.1 (s), 142.4 (s), 136.5 (s), 135.5 (d), 126.2 (d), 123.3 (d), 42.3 (d), 35.2 (t), 34.6 (t), 33.6 (t), 22.2 (t), 16.4 (q), 13.9 (q) ppm; GC/MS (EI): m/z (%): 202 (58) [M.sup.+], 187 (56), 159 (100), 145 (17), 131 (25), 115 (25), 104 (9).

COMPARISON EXAMPLE 1: 5-ISOBUTYL-2-METHYL-2,3-DIHYDRO-1H-INDEN-1-ONE

(75) The title compound was prepared, following the general procedure C as described in Example 1. 7-Bromo-2-methyl-2,3-dihydro-1H-inden-1-one and 5-bromo-2-methyl-2,3-dihydro-1H-inden-1-one (mixture of two isomers, ratio=15:85, 4.00 g, 17.77 mmol), isobutylboronic acid (3.63 g, 35.5 mmol), potassium carbonate (7.37 g, 53.3 mmol), palladium (II) acetate (0.140 g, 0.533 mmol) and 1,1′-bis(diphenylphosphino)ferrocene (dppf ligand: 0.369 g, 0.666 mmol) in toluene (100 mL) were reacted at reflux under argon atmosphere for 2 h to give 5-isobutyl-2-methyl-2,3-dihydro-1H-inden-1-one as a colorless liquid (2.67 g, 74% yield) and 7-isobutyl-2-methyl-2,3-dihydro-1-inden-1-one as a colorless liquid (0.54 g, 15% yield).

(76) Odor description: fruity fatty citrus green, fruity citral green, soapy

(77) .sup.1H NMR (300 MHz, CDCl.sub.3): δ=7.65 (d, J=7.8 Hz, 1H), 7.21 (s, 1H), 7.14 (d, J=7.8 Hz, 1H), 3.35 (dd, J=18.0, 8.7 Hz, 1H), 2.65-2.71 (m, 2H), 2.54 (d, J=7.2 Hz, 2H), 1.86-1.95 (m, 1H), 1.29 (d J=7.2 Hz, 3H), 0.92 (d, J=6.6 Hz, 6H) ppm; .sup.13C NMR (75 MHz, CDCl.sub.3): δ=208.9 (s), 153.8 (s), 149.5 (s), 134.3 (s), 128.6 (d), 126.9 (d), 123.6 (d), 45.7 (t), 42.1 (d), 34.8 (t), 30.2 (d), 22.312 (q), 16.3 (q) ppm; GC/MS (EI): m/z (%): 202 (75) [M.sup.+], 187 (55), 160 (100), 146 (65), 115 (31), 91 (17).

COMPARISON EXAMPLE 2: 2-METHYL-5-PROPYL-2,3-DIHYDRO-1H-INDEN-1-ONE AND 2-METHYL-7-PROPYL-2,3-DIHYDRO-1H-INDEN-1-ONE

(78) The title compound was prepared, following the general procedure C as described in Example 1. 7-Bromo-2-methyl-2,3-dihydro-1H-inden-1-one and 5-bromo-2-methyl-2,3-dihydro-1H-inden-1-one (mixture of two isomers, ratio=15:85, 4.00 g, 17.77 mmol), propyboronic acid (3.63 g, 35.5 mmol), potassium carbonate (7.37 g, 53.3 mmol), palladium (II) acetate (0.140 g, 0.533 mmol) and dppf (0.369 g, 0.666 mmol) in toluene (100 mL) were reacted at reflux under argon atmosphere for 2 h to give 2-methyl-5-propyl-2,3-dihydro-1H-inden-1-one as a colorless liquid (2.30 g, 69% yield) and 2-methyl-7-propy-2,3-dihydro-1-inden-1-one as a colorless liquid (0.60 g, 18% yield).

(79) 2-methyl-7-propyl-2,3-dihydro-1H-inden-1-one: .sup.1H NMR (300 MHz, CDCl.sub.3): δ=7.40-7.45 (m, 1H), 7.24 (d, J=7.5 Hz, 1H), 7.10 (d, J=7.5 Hz, 1H), 3.28-3.37 (m, 1H), 2.99-3.05 (m, 2H), 2.62-2.72 (m, 2H), 1.58-1.67 (m, 2H), 1.29 (d, J=6.9 Hz, 3H), 0.97 (t, J=7.2 Hz, 3H) ppm; .sup.13C NMR (75 MHz, CDCl.sub.3): δ=209.9 (s), 154.3 (s), 143.9 (s), 133.9 (d), 133.3 (s), 128.3 (d), 123.9 (d), 42.3 (d), 34.6 (t), 33.6 (t), 24.1 (t), 16.3 (q), 14.0 (q) ppm; GC/MS (EI): m/z (%): 188 (70) [M.sup.+], 173 (100), 160 (55), 145 (39), 128 (17), 115 (30), 91 (17).

(80) Odor description (7-propyl): floral, rose, metallic

(81) 2-methyl-5-propyl-2,3-dihydro-1H-inden-1-one: .sup.1H NMR (300 MHz, CDCl.sub.3): δ=7.66 (d, J=7.8 Hz, 1H), 7.24 (s, 1H), 7.17 (d, J=7.8 Hz, 1H), 3.31-3.40 (m, 1H), 2.63-2.72 (m, 4H), 1.61-1.73 (m, 2H), 1.30 (d, J=7.2 Hz, 3H), 0.96 (t, J=7.2 Hz, 3H) ppm; .sup.13C NMR (75 MHz, CDCl.sub.3): δ=208.9 (s), 153.9 (s), 150.5 (s), 134.3 (s), 128.1 (d), 126.3 (d), 123.8 (d), 42.1 (d), 38.4 (t), 34.9 (t), 24.4 (t), 16.4 (q), 13.8 (q) ppm; GC/MS (EI): m/z (%): 188 (48) [M.sup.+], 173 (100), 159 (28), 145 (19), 131 (20), 115 (20), 91 (12).

(82) Odor description (5-propyl): green, waxy, fatty.

COMPARISON EXAMPLE 3: 2-METHYL-4-PROPYL-2,3-DIHYDRO-1H-INDEN-1-ONE

(83) The title compound was prepared, following the general procedure C as described in Example 1. 4-Bromo-2-methyl-2,3-dihydro-1H-inden-1-one (1.50 g, 3.66 mmol), propylboronic acid (1.17 g, 13.3 mmol), potassium carbonate (2.76 g, 20.0 mmol), palladium (II) acetate (0.075 g, 0.333 mmol) and dppf (0.222 g, 0.400 mmol) in toluene (30 mL) were reacted at reflux under argon atmosphere for 2 h to give 2-methyl-4-propyl-2,3-dihydro-1H-inden-1-one as a colorless liquid (1.05 g, 84% yield).

(84) Odor description: very weak, fruity, floral.

(85) .sup.1H NMR (300 MHz, CDCl.sub.3): δ=7.59 (d, J=7.5 Hz, 1H), 7.39 (d, J=7.2 Hz, 1H), 7.27-7.32 (m, 1H), 3.34 (dd, J=16.5, 7.2 Hz, H), 2.59-2.72 (m, 4H) 1.60-1.73 (m, 2H), 1.31 (d, J=7.5 Hz, 3H), 0.99 (t, J=7.2 Hz, 3H) ppm; .sup.13C NMR (75 MHz, CDCl.sub.3): δ=209.7 (s), 151.9 (s), 140.2 (s), 136.2 (s), 134.3 (d), 127.6 (d), 121.4 (d), 41.8 (d), 34.0 (t), 33.5 (t), 23.0 (t), 18.3 (q), 14.0 (q) ppm; GC/MS (EI): m/z (%): 188 (73) [M.sup.+], 173 (100), 159 (80), 145 (35), 131 (28), 115 (35), 91 (25).

COMPARISON EXAMPLE 4: 2-METHYL-5-(2-METHYLALLYL)-2,3-DIHYDRO-1H-INDEN-1-ONE AND 2-METHYL-7-(2-METHYLALLYL)-2,3-DIHYDRO-1H-INDEN-1-ONE

(86) Using similar procedure as described in Example 22, Cesium carbonate (7.60 g, 23.3 mmol), palladium (II) acetate (0.175 g, 0.78 mmol), triphenylphosphine (0.82 g, 3.11 mmol), 3-Isopropyl-2,5-dimethylhex-5-en-3-ol (318 g, 18.7 mmol) and 7-bromo-2-methyl-2,3-dihydro-1H-inden-1-one and 5-bromo-2-methyl-2,3-dihydro-1H-inden-1-one (mixture of two isomers, ratio=15: 85, 3.50 g: 15.6 mmol) in toluene (80 mL) were reacted at reflux under argon atmosphere for 2 h to give 2-methyl-5-(2-methylallyl)-2,3-dihydro-1H-inden-1-one (222 g, 71% yield, colorless liquid) and 2-methyl-7-(2-methylallyl)-2:3-dihydro-1H-inden-1-one (0.41 g, 13% yield, colorless liquid).

(87) 2-Methyl-5-(2-methylallyl)-2,3-dihydro-1H-inden-1-one: .sup.1H NMR (300 MHz, CDCl.sub.3): δ=7.88 (d, J=1.8 Hz, 1H), 7.27 (s, 1H), 7.21 (d, J=7.8 Hz, 1H), 4.86 (s, 1H), 4.77 (s, 1H), 3.39 (s, 2H), 3.33-3.41 (m, 1H), 2.67-2.73 (m, 2H), 1.69 (s, 3H), 1.31 (d, J=7.2 Hz, 4H) ppm; .sup.13C NMR (75 MHz, CDCl.sub.6): δ=209.1 (s), 154.0 (s), 147.5 (s), 144.2 (s), 134.7 (s), 128.5 (d), 126.7 (d), 123.9 (d), 112.8 (t), 45.0 (t), 42.2 (d), 34.9 (t) 22.1 (q), 16.4 (q) ppm; GC/MS (EI): m/z (%): 200 (55) [M.sup.+], 185 (100), 172 (48), 15(71), 143 (72), 129 (60), 115 (53), 91 (17).

(88) Odor description: fatty fruity citrus floral, “citral myraldyl”-like, soapy.

(89) 2-methyl-7-(2-methylallyl)-2,3-dihydro-1H-inden-1-one: .sup.1H NMR (300 MHz, CDCl.sub.3): δ=7.47 (dd, J=7.5, 7.5 Hz, 1H), 7.29 (d, J=7.5 Hz, 1H), 7.15 (d, J=7.5 Hz, 1H), 4.79 (s, 1H), 4.57 (s, 1H), 3.75-3.91 (m, 2H), 3.30-3.39 (m, 1H), 2.63-2.72 (m, 2H), 1.75 (s, 3H), 1.29 (d, J=7.2 Hz, 3H) ppm; .sup.13C NMR (75 MHz, CDCl.sub.3): δ=209.9 (s), 154.2 (s), 144.9 (s), 140.6 (s), 134.0 (d), 133.6 (s), 128.8 (d), 124.3 (d), 111.7 (t), 42.4 (d), 38.6 (t), 34.5 (t) 22.7 (q), 16.3 (q) ppm; GC/MS (EI): m/z (%): 200 (30) [M.sup.+], 185 (100), 167 (11), 143 (10), 115 (22), 91 (7).

(90) Odor description: green, wax, slightly minty.

COMPARISON EXAMPLE 5: 2-METHYL-4-(2-METHYLALLYL)-2,3-DIHYDRO-1H-INDEN-1-ONE

(91) The title compound was prepared, following the general as described in Example 22. Cesium carbonate (3.26 g, 10.0 mmol), palladium (II) acetate (0.075 g, 0.33 mmol), triphenylphosphine (0.35 g, 1.33 mmol), 3-isopropyl-2,5-dimethylhex-5-en-3-ol (1.36 g, 8.00 mmol) and 4-bromo-2-methyl-2,3-dihydro-1H-inden-1-one (1.50 g, 6.66 mol) in toluene (35 mL) were reacted at reflux under argon atmosphere for 2 h to give 2-methyl-4-(2-methylallyl)-2,3-dihydro-1H-inden-1-one as a colorless liquid (1.12 g, 84% yield).

(92) .sup.1H NMR (300 MHz, CDCl.sub.3): δ=7.65 (d, J=7.5 Hz, 1H), 7.41 (d, J=7.5 Hz, 1H), 7.34 (dd, J=7.5, 7.5 Hz, 1H), 4.85 (s, 1H), 4.63 (s, 1H), 3.38 (s, 2H), 3.30-3.38 (m, 1H), 2.68-2.74 (m, 1H), 2.62 (dd, J=17.1, 3.9 Hz, 1H), 1.73 (s, 3H), 1.31 (d, J=7.5 Hz, 3H) ppm; .sup.13C NMR (75 MHz, CDCl.sub.3): δ=209.8 (s), 152.7 (s), 143.1 (s), 137.2 (s), 136.4 (s), 135.2 (d), 127.7 (d), 122.0 (d), 112.4 (t), 41.9 (d), 40.7 (t), 33.5 (t), 22.4 (q), 16.4 (q) ppm; GC/MS (EI): m/z (%): 200 (100) [M.sup.+], 185 (65), 157 (60), 143 (42), 115 (47), 91 (13).

(93) Odor description: fruity floral metallic, myradyl-like.

COMPARISON EXAMPLE 6: 5-CYCLOPROPYL-2-METHYL-2,3-DIHYDRO-1H-INDEN-1-ONE, AND 7-CYCLOPROPYL-2-METHYL-2,3-DIHYDRO-1H-INDEN-1-ONE

(94) The title compound was prepared, following the general procedure C as described in Example 1. 7-Bromo-2-methyl-2,3-hydro-1H-inden-1-one and 5-bromo-2-methyl-2,3-dihydro-1H-inden-1-one (mixture of two isomers, ratio=15:85, 3.00 g, 13.33 mmol), cyclopropylboronic acid (2.29 g, 26.7 mmol), potassium carbonate (5.53 g, 40.0 mmol), palladium (II) acetate (0.120 g, 0.533 mmol) and 1,1′-bis(diphenylphosphino)ferrocene (dppf ligand, 0.389 g, 0.666 mmol) in toluene (100 ml) were reacted at reflux under argon atmosphere for 2 h followed by distillation through Kugelrohr to give 5-cyclopropyl-2-methyl-2,3-dihydro-1H-inden-1-one (140° C./0.11 mbar) as a colorless liquid (2.02 g, 81% yield) and 7-cyclopropyl-2-methyl-2,3-dihydro-1H-inden-1-one (130° C./0.11 mbar) as a colorless liquid (0.300 g, 12% yield).

(95) 5-Cyclopropyl-2-methyl-2,3-dihydro-1H-inden-1-one: .sup.1H NMR (300 MHz, CDCl.sub.3): δ=7.61 (d, J=8.1 Hz, 1H), 7.08 (s, 1H), 7.02 (d, J=7.8 Hz, 1H), 3.27-3.36 (m, 1H), 2.60-2.70 (m, 2H), 1.92-1.97 (m, 1H), 1.28 (d, J=7.2 Hz, 3H), 1.03-1.10 (m, 2H), 1.77-1.80 (m, 2H) ppm: .sup.13C NMR (75 MHz, CDCl.sub.3): δ=208.6 (s), 153.9 (s), 152.4 (s), 134.0 (s), 125.0 (d), 123.8 (d), 122.9 (d), 42.1 (d), 34.8 (t), 16.4 (q), 16.1 (d), 10.6 (t), 10.6 (t) ppm; GC/MS (EI): m/z (%): 186 (50) [M.sup.+], 171 (100), 158 (10), 143 (19), 128 (31), 115 (33).

(96) Odor description: green, creamy, lactonic.

(97) 7-Cyclopropyl-2-methyl-2,3-dihydro-1H-inden-1-one: .sup.1H NMR (300 MHz, CDCl.sub.3) δ=7.36-7.41 (m, 1H), 7.15 (d, J=7.5 Hz, 1H), 6.71 (d, J=7.5 Hz, 1H), 3.25-3.34 (m, 2H), 2.60-2.70 (m, 2H), 1.30 (d, J=7.2 Hz, 3H), 1.05-1.10 (m, 2H), 0.72-0.76 (m, 2H) ppm; .sup.13C NMR (75 MHz, CDCl.sub.3): δ=210.4 (s), 154.0 (s), 146.1 (s), 134.3 (d), 133.5 (s), 122.9 (d), 121.0 (d), 42.4 (d), 34.4 (t), 18.4 (q), 10.7 (t), 10.6 (t), 10.0 (d) ppm; GC/MS (EI): m/z (%): 186 (30) [M.sup.+], 171 (100), 153 (9), 141 (12), 128 (31), 115 (28).

(98) Odor description: green, floral, leathery.

COMPARISON EXAMPLE 7: 4-CYCLOPROPYL-2-METHYL-2,3-DIHYDRO-1H-INDEN-1-ONE

(99) The title compound was prepared, following the general procedure C as described in Example 1. 4-Bromo-2-methyl-2,3-dihydro-1H-inden-1-one (1.50 g, 6.66 mmol), cyclopropylboronic acid (1.15 g, 13.33 mmol), potassium carbonate (2.78 g, 19.99 mmol), palladium (II) acetate (0.075 g, 0.333 mmol) and 1,1′-bis(diphenylphosphino)ferrocene (dppf ligand, 0.222 g, 0.400 mmol) in toluene (30 ml) were reacted at reflux under argon atmosphere for 2 h followed by distillation through Kugelrohr (125° C./0.08 mbar) to give to give 4-cyclopropyl-2-methyl-2,3-dihydro-1H-inden-1-one as a colorless liquid (1.11 g, 89% yield).

(100) .sup.1H NMR (300 MHz, CDCl.sub.3): δ=7.54 (d, J=7.5 Hz, 1H), 7.24-7.29 (m, 1H), 7.09 (d, J=7.5 Hz, 1H), 3.45 (dd, J=17.7, 8.7 Hz, 1H), 2.67-2.76 (m, 2H), 1.88-1.97 (m, 1H), 1.33 (d, J=7.2 Hz, 3H), 0.99-1.05 (m, 2H), 0.71-0.74 (m, 2H) ppm; .sup.13C NMR (75 MHz, CDCl.sub.3): δ=209.7 (s), 152.9 (s), 141.3 (s), 136.9 (s), 129.5 (d), 127.7 (d), 120.9 (d), 41.8 (d), 33.6 (t), 16.4 (q), 11.7 (q), 7.9*2 (t) ppm; GC/MS (EI): m/z (%): 186 (100) [M.sup.+], 171 (71), 157 (29), 143 (85), 128 (91), 115 (65), 91 (11).

(101) Odor description: weak floral.

EXAMPLE 24: DETERMINATION OF GC-ODOR THRESHOLD VALUES

(102) According to standard procedures known to the person skilled in the art, threshold values for volatile perfumery compounds are determined on a gas chromatograph equipped with a sniff port by a panel of trained evaluators. The lowest concentration smelled by each panelist is recorded as the individual threshold value expressed in ng (absolute amount of compound delivered at the sniff port).

(103) Under identical conditions the odor threshold value for the individual compounds was measured. The results are given below.

(104) TABLE-US-00001 odor threshold Compound value [ng] 6-isobutyl-2-methyl-2,3-dihydro-1H-inden-1-one 0.06 5-isobutyl-2-methyl-2,3-dihydro-1H-inden-1-one 1.56 2-methyl-6-propyl-2,3-dihydro-1H-inden-1-one 0.04 2-methyl-5-propyl-2,3-dihydro-1H-inden-1-one 0.98 2-methyl-4-propyl-2,3-dihydro-1H-inden-1-one 6.25 2-methyl-6-(2-methylallyl)-2,3-dihydro-1H-inden-1-one 0.24 2-methyl-7-(2-methylallyl)-2,3-dihydro-1H-inden-1-one 4.96 2-methyl-4-(2-methylallyl)-2,3-dihydro-1H-inden-1-one 6.25 6-Cyclopropyl-2-methyl-2,3-dihydro-1H-inden-1-one 0.46 7-Cyclopropyl-2-methyl-2,3-dihydro-1H-inden-1-one 4.31 4-Cyclopropyl-2-methyl-2,3-dihydro-1H-inden-1-one 31.7

(105) As can be seen from the results above the compounds of the present invention (C-6 substituted indanone derivatives) have an odor threshold value which is at least about 10 times lower compared to the compounds substituted at C-4, C-5 or C-7 position. Based on this, a significant advance is achieved because much smaller amount of the claimed compounds is required to impart the same odor intensity.

EXAMPLE 25: ROSY FRAGRANCE COMPOSITION FOR FINE PERFUMERY

(106) TABLE-US-00002 parts by weight Compound/Ingredient 1/1000 Beta Ionone 1 Linalool 3 2-Cis-3,7-Dimethyl-2,6-Octadien-1-ol (Nerolex) 30 Citronellol 40 Rhodinol ™ 60 Geraniol 80 Phenyl ethyl alcohol 302 3,7-Dimethyl-6-octenal (Citronellal) @ 10% DPG 2 3,7-Dimethylocta-2,6-dienal (Citral Lemarome N) 3 3,7-Dimethyl-6-octen-1-yl acetate (Citronellyl acetate) 5 Neryl acetate (CAS 141-12-8) 5 Geranyl acetate (CAS 105-87-3) 15 Methyl phenyl acetate 2 Benzyl Methyl Ether @ 10% DPG 2 2-Phenylethyl 2-methylbutyrate (Anatolyl ™) 3 2-Phenylethyl 2-phenylacetate 5 2-Phenylethyl acetate 15 3,7-Dimethyl-1,3,6-octatriene (Ocimene) 1 Caryophyllene (CAS 87-44-5) 2 Eugenol 10 n-Octanal (food grade) @10% DPG 1 n-Nonanal (food grade) @ 10% DPG 2 4-Methyl-2-(2-methylprop-1-enyl)tetrahydro-2H-pyran 3 (Rose Oxyde CO) n-Hexyl acetate @ 10% DPG 2 cis-3-Hexenol @ 10% DPG 3 cis-3-Hexenyl acetate @ 10% DPG 4 1-(2,6,6-Trimethyl-1,3-cyclohexadien-1-yl)-2-buten-1-one 7 (Damascenone @ 1% DPG) Beta Damascone @ 1% DPG 7 Dipropylen glycol (DPG) 375 6-isobutyl-2-methyl-2,3-dihydro-1H-inden-1-one (Example 1) 10 Total: 1000

(107) This natural rose, spicy (clove) fresh light and delicate accord with slightly fruity (apple) facets is best to be assessed at 10 weight % in alcohol (85). The addition of 6-isobutyl-2-methyl-2,3-dihydro-1H-inden-1-one results in a much more impact accord, and the character is now fruity peach creamy, with a rose floral freshness. The accord has now more body, and is more long lasting compared to an accord without wherein the compound of formula (I) is replaced by DPG. This accord above is, e.g., suitable for fragrancing a softener.