ORGANIC COMPOUNDS

Abstract

Disclosed are cyclopent-2-enone derivatives possessing woody odor profile with some peppery notes.

Claims

1. A method of using a compound of formula (I) or a mixture thereof as a fragrance or flavor ##STR00009## wherein indicates a carbon-carbon single or double bond, R is hydrogen and R.sup.1 is hydrogen or methyl, or R and R.sup.1 form together with the C-atom to which they are attached a vinyl group, R.sup.2 is selected from methyl and ethyl, R.sup.3 and R.sup.4 are hydrogen, or R.sup.3 and R.sup.4 together with the CC bond represent a double bond, or R.sup.2 and R.sup.3 form together a methylene group, R.sup.5 is selected from C.sub.5-C.sub.7 alkyl and C.sub.5-C.sub.7 alkenyl, and R.sup.6 is selected from hydrogen and methyl.

2. The method according to claim 1 wherein the compound of formula (I) is selected from the group consisting of 3-methyl-2-(oct-5-en-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(6-methylhept-5-en-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(6-methylocta-2,5-dien-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(6-methylocta-1,5-dien-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(6-methyloct-5-en-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(octa-2,5-dien-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(octa-1,5-dien-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(nonan-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(non-5-en-2-yl)cyclopent-2-en-1-one; 3,4-dimethyl-2-(6-methylhept-5-en-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(5-methylhept-4-en-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(5-methylheptan-2-yl)cyclopent-2-en-1-one; 2-(4,7-dimethyloct-6-en-2-yl)-3-methylcyclopent-2-en-1-one; 2-(6-methylhept-5-en-2-yl)-3-vinylcyclopent-2-en-1-one; 3-ethyl-2-(6-methylhept-5-en-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(6-methylheptan-2-yl)cyclopent-2-en-1-one; 3-ethyl-2-(6-methylheptan-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(octan-2-yl)cyclopent-2-en-1-one; 3-ethyl-2-(oct-5-en-2-yl)cyclopent-2-en-1-one; 2-(oct-5-en-2-yl)-3-vinylcyclopent-2-en-1-one and mixtures thereof.

3. The method according to claim 1 wherein the indicates a carbon-carbon double bond, and a compound of formula (II) ##STR00010## wherein R.sup.1 is hydrogen or methyl, R.sup.2 is selected from methyl and ethyl, R.sup.3 and R.sup.4 are hydrogen, or R.sup.3 and R.sup.4 together with the CC bond represent a double bond, or R.sup.2 and R.sup.3 form together a methylene group, R.sup.5 is selected from C.sub.5-C.sub.7 alkyl and C.sub.5-C.sub.7 alkenyl, and R.sup.6 is selected from hydrogen and methyl.

4. A fragrance composition comprising a compound of formula (I) or a mixture thereof ##STR00011## wherein indicates a carbon-carbon single or double bond, R is hydrogen and R.sup.1 is hydrogen or methyl, or R and R.sup.1 form together with the C-atom to which they are attached a vinyl group, R.sup.2 is selected from methyl and ethyl, R.sup.3 and R.sup.4 are hydrogen, or R.sup.3 and R.sup.4 together with the CC bond represent a double bond, or R.sup.2 and R.sup.3 form together a methylene group, R.sup.5 is selected from C.sub.5-C.sub.7 alkyl, and C.sub.5-C.sub.7 alkenyl, and R.sup.6 is selected from hydrogen and methyl; and at least one other odorant.

5. The fragrance composition according to claim 4, wherein the compound is selected from the group consisting of 3-methyl-2-(oct-5-en-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(6-methylocta-2,5-dien-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(6-methylocta-1,5-dien-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(6-methyloct-5-en-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(octa-2,5-dien-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(octa-1,5-dien-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(nonan-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(non-5-en-2-yl)cyclopent-2-en-1-one; 3,4-dimethyl-2-(6-methylhept-5-en-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(5-methylhept-4-en-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(5-methylheptan-2-yl)cyclopent-2-en-1-one; 2-(4,7-dimethyloct-6-en-2-yl)-3-methylcyclopent-2-en-1-one; 2-(6-methylhept-5-en-2-yl)-3-vinylcyclopent-2-en-1-one; 3-ethyl-2-(6-methylhept-5-en-2-yl)cyclopent-2-en-1-one; 3-ethyl-2-(6-methylheptan-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(octan-2-yl)cyclopent-2-en-1-one; 3-ethyl-2-(oct-5-en-2-yl)cyclopent-2-en-1-one; 2-(oct-5-en-2-yl)-3-vinylcyclopent-2-en-1-one and mixtures thereof.

6. A fragranced article comprising a) as odorant a compound of formula (I) ##STR00012## wherein indicates a carbon-carbon single or double bond, R is hydrogen and R.sup.1 is hydrogen or methyl, or R and R.sup.1 form together with the C-atom to which they are attached a vinyl group, R.sup.2 is selected from methyl and ethyl, R.sup.3 and R.sup.4 are hydrogen, or R.sup.3 and R.sup.4 together with the CC bond represent a double bond, or R.sup.2 and R.sup.3 form together a methylene group, R.sup.5 is selected from C.sub.5-C.sub.7 alkyl and C.sub.5-C.sub.7 alkenyl, and R.sup.6 is selected from hydrogen and methyl; and b) a consumer product base.

7. The fragranced article according to claim 6 wherein the odorant compound is a compound of formula (I) where indicates a carbon-carbon double bond.

8. The fragranced article according to claim 7 further comprising as odorant a compound of formula (II) ##STR00013## wherein R.sup.1 is hydrogen or methyl, R.sup.2 is selected from methyl and ethyl, R.sup.3 and R.sup.4 are hydrogen, or R.sup.3 and R.sup.4 together with the CC bond represent a double bond, or R.sup.2 and R.sup.3 form together a methylene group, R.sup.5 is selected from C.sub.5-C.sub.7 alkyl and C.sub.5-C.sub.7 alkenyl, and R.sup.6 is selected from hydrogen and methyl.

9. The fragranced article according to claim 6 wherein the consumer product base is selected from fine perfumery, personal care products and fabric care products.

10. 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) or a mixture thereof ##STR00014## wherein indicates a carbon-carbon single or double bond, R is hydrogen and R.sup.1 is hydrogen or methyl, or R and R.sup.1 form together with the C-atom to which they are attached a vinyl group, R.sup.2 is selected from methyl and ethyl, R.sup.3 and R.sup.4 are hydrogen, or R.sup.3 and R.sup.4 together with the CC bond represent a double bond, or R.sup.2 and R.sup.3 form together a methylene group, R.sup.5 is selected from Cs-C.sub.7 alkyl and C.sub.5-C.sub.7 alkenyl, and R.sup.6 is selected from hydrogen and methyl.

11. The method according to claim 10 comprising a mixture comprising a compound of formula (I) and a compound of formula (II) ##STR00015## wherein R is hydrogen, R.sup.1 is hydrogen or methyl, R.sup.2 is selected from methyl and ethyl, R.sup.3 and R.sup.4 are hydrogen, or R.sup.3 and R.sup.4 together with the CC bond represent a double bond, or R.sup.2 and R.sup.3 form together a methylene group, R.sup.5 is selected from C.sub.5-C.sub.7 alkyl, and C.sub.5-C.sub.7 alkenyl, and R.sup.6 is selected from hydrogen and methyl.

12. A compound of formula (I) ##STR00016## wherein indicates a carbon-carbon single or double bond, R is hydrogen and R.sup.1 is hydrogen or methyl, or R and R.sup.1 form together with the C-atom to which they are attached a vinyl group, R.sup.2 is selected from methyl and ethyl, R.sup.3 and R.sup.4 are hydrogen, or R.sup.3 and R.sup.4 together with the CC bond represent a double bond, or R.sup.2 and R.sup.3 form together a methylene group, R.sup.5 is selected from C.sub.5-C.sub.7 alkyl and C.sub.5-C.sub.7 alkenyl, and R.sup.6 is selected from hydrogen and methyl; with the proviso that the compound is not a compound of formula (I) wherein R.sup.2 is methyl, R, R.sup.1, R.sup.3, R.sup.4 and R.sup.6 are hydrogen and R.sup.5 is selected from 3-methyl (but-2-enyl) and 3-methyl (butyl), and is not 3-methyl-2-(6-methylhepta-2,5-dien-2-yl)cyclopent-2-en-1-one.

13. The compound according to claim 12 wherein the compound is selected from the group consisting of 3-methyl-2-(oct-5-en-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(6-methylocta-2,5-dien-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(6-methylocta-1,5-dien-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(6-methyloct-5-en-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(octa-2,5-dien-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(octa-1,5-dien-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(nonan-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(non-5-en-2-yl)cyclopent-2-en-1-one; 3,4-dimethyl-2-(6-methylhept-5-en-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(5-methylhept-4-en-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(5-methylheptan-2-yl)cyclopent-2-en-1-one; 2-(4,7-dimethyloct-6-en-2-yl)-3-methylcyclopent-2-en-1-one; 2-(6-methylhept-5-en-2-yl)-3-vinylcyclopent-2-en-1-one; 3-ethyl-2-(6-methylhept-5-en-2-yl)cyclopent-2-en-1-one; 3-ethyl-2-(6-methylheptan-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(octan-2-yl)cyclopent-2-en-1-one; 3-ethyl-2-(oct-5-en-2-yl)cyclopent-2-en-1-one; 2-(oct-5-en-2-yl)-3-vinylcyclopent-2-en-1-one and mixtures thereof.

14. The fragranced article according to claim 8 wherein the consumer product base is selected from fine perfumery, personal care products and fabric care products.

Description

DETAILED DESCRIPTION

[0037] The present invention is based on the surprising finding that cyclopent-2-enone derivatives of formula (I) possessing powerful woody odor profile with some peppery notes.

[0038] In a first aspect of the invention, there is provided the use as fragrance or flavour of a compound of formula (I) in the form of any one of its stereoisomers or mixture thereof

##STR00003## [0039] wherein [0040] is indicating a carbon-carbon single or double bond [0041] R is hydrogen and R.sup.1 is hydrogen or methyl, or [0042] R and R.sup.1 form together with the C-atom to which they are attached a vinyl group, [0043] R.sup.2 is selected from methyl and ethyl, [0044] R.sup.3 and R.sup.4 are hydrogen, or [0045] R.sup.3 and R.sup.4 together with the CC bond represent a double bond, or [0046] R.sup.2 and R.sup.3 form together a methylene group, [0047] R.sup.5 is selected from C.sub.5-C.sub.7 alkyl, and C.sub.5-C.sub.7 alkenyl, and [0048] R.sup.6 is selected from hydrogen and methyl.

[0049] In one particular embodiment the compound is a compound of formula (I) wherein R.sup.2 is methyl and R.sup.3 and R.sup.4 are hydrogen.

[0050] In another particular embodiment the compound is a compound of formula (I) wherein R.sup.2 is methyl and R.sup.3 and R.sup.4 together with the CC bond represent a double bond.

[0051] In another particular embodiment the compound is a compound of formula (I) wherein R.sup.2 and R.sup.3 form together a methylene group and R.sup.4 is hydrogen.

[0052] In another particular embodiment the compound is a compound of formula (I) wherein is indicating a carbon-carbon double bond.

[0053] In another particular embodiment the compound is a compound of formula (I) wherein R.sup.5 is selected from C.sub.5 to C.sub.7 linear or branched alkenyl (including C.sub.6 alkenyl) comprising one double bond. For example, R.sup.5 is selected from the group consisting of pent-2-enyl, 3-methyl (but-2-enyl), 3-methyl (pent-2-enyl), hex-2-enyl, 2-methyl (but-1-enyl), and 2-methyl (but-2-enyl).

[0054] In another particular embodiment the compound is a compound of formula (I) wherein R.sup.5 is selected from C.sub.5 to C.sub.7 linear or branched alkyl (including C.sub.6 alkyl), such as 2-methyl butyl, 3-methyl butyl, pentyl, and hexyl.

[0055] In another particular embodiment the compound is a compound of formula (I) wherein R.sup.2 is methyl, R.sup.3 and R.sup.4 are hydrogen, and R.sup.5 is selected from C.sub.5 to C.sub.7 linear or branched alkenyl (including C.sub.6 alkenyl) comprising one double bond (e.g. R.sup.5 is selected from the group consisting of pent-2-enyl, 3-methyl (but-2-enyl), 3-methyl (pent-2-enyl), hex-2-enyl, 2-methyl (but-1-enyl), and 2-methyl (but-2-enyl)).

[0056] In another particular embodiment there is provided a compound of formula (I) wherein R.sup.2 is methyl, R.sup.3 and R.sup.4 are hydrogen, and R.sup.5 is selected from C.sub.5 to C.sub.6 hydrocarbon residue comprising up to one double bond.

[0057] One may cite 3-methyl-2-(nonan-2-yl)cyclopent-2-en-1-one possessing peppery, wood odour profile with some floral, green, metallic, rooty, fenugreek odour characteristics.

[0058] As a further specific example one may cite 3-methyl-2-(6-methylhept-5-en-2-yl)cyclopent-2-en-1-one possessing peppery, woody odour profile with some green, floral aspects. It was observed that (R)-3-methyl-2-(6-methylhept-5-en-2-yl)cyclopent-2-en-1-one is about 15 times more powerful than ((S)-3-methyl-2-(6-methylhept-5-en-2-yl)cyclopent-2-en-1-one)-3-methyl-2-(6-methylhept-5-en-2-yl)cyclopent-2-en-1-one. From an olfactory view point the (R) enantiomer was slightly preferred over the(S) enantiomer due to their warm black peppery note, and the patchouli leaves side note.

[0059] In another particular embodiment there is provided a mixture comprising a compound of formula (I) wherein R.sup.2 and R.sup.3 form together a methylene group and a compound of formula (I) wherein R.sup.3 and R.sup.4 together with the CC bond represent a double bond.

[0060] Further non-limiting examples are compounds of formula (I) selected from the group consisting of 3-methyl-2-(oct-5-en-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(6-methylocta-2,5-dien-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(6-methylocta-1,5-dien-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(6-methyloct-5-en-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(octa-2,5-dien-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(octa-1,5-dien-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(non-5-en-2-yl)cyclopent-2-en-1-one; 3,4-dimethyl-2-(6-methylhept-5-en-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(5-methylhept-4-en-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(5-methylheptan-2-yl)cyclopent-2-en-1-one; 2-(4,7-dimethyloct-6-en-2-yl)-3-methylcyclopent-2-en-1-one; 2-(6-methylhept-5-en-2-yl)-3-vinylcyclopent-2-en-1-one; 3-ethyl-2-(6-methylhept-5-en-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(6-methylheptan-2-yl)cyclopent-2-en-1-one; 3-ethyl-2-(6-methylheptan-2-yl)cyclopent-2-en-1-one; 3-methyl-2-(octan-2-yl)cyclopent-2-en-1-one; 3-ethyl-2-(oct-5-en-2-yl)cyclopent-2-en-1-one (including (E)-3-ethyl-2-(oct-5-en-2-yl)cyclopent-2-en-1-one); and 2-(oct-5-en-2-yl)-3-vinylcyclopent-2-en-1-one (including (E)-2-(oct-5-en-2-yl)-3-vinylcyclopent-2-en-1-one).

[0061] The compounds according to the present invention comprise one or more chiral centres and as such may exist as a mixture of stereoisomers, or they may be resolved as isomerically pure forms. Resolving stereoisomers adds to the complexity of manufacture and purification of these compounds and so it is preferred to use the compounds as mixtures of their stereoisomers simply for economic reasons. However, if it is desired to prepare individual stereoisomers, this may be achieved according to methodology known in the art, e.g. preparative HPLC and GC or by stereoselective syntheses.

[0062] The compounds of formula (I) may be used alone, as isomeric mixture thereof, or in combination with known odorant molecules selected from the extensive range of natural products, and synthetic molecules currently available, such as essential oils, alcohols, aldehydes and ketones, ethers and acetals, esters and lactones, macrocycles and heterocycles, and/or in a mixture with one or more ingredients or excipients conventionally used in conjunction with odorants in fragrance compositions, for example, carrier materials, and other auxiliary agents commonly used in the art.

[0063] As used herein, carrier material means a material which is practically neutral from an odorant point of view, i.e. a material that does not significantly alter the organoleptic properties of odorants.

[0064] The term auxiliary agent refers to ingredients that might be employed in a fragrance composition for reasons not specifically related to the olfactive performance of said composition. For example, an auxiliary agent may be an ingredient that acts as an aid to processing a fragrance ingredient or ingredients, or a composition containing said ingredient(s), or it may improve handling or storage of a fragrance ingredient or composition containing same. It might also be an ingredient that provides additional benefits such as imparting color or texture. It might also be an ingredient that imparts light resistance or chemical stability to one or more ingredients contained in a fragrance composition. A detailed description of the nature and type of adjuvants commonly used in fragrance compositions containing same cannot be exhaustive, but it has to be mentioned that said ingredients are well known to a person skilled in the art.

[0065] As used herein, fragrance composition means any composition comprising a compound of formula (I) (which encompasses compounds of formula (Ia)), or a mixture thereof and a base material, e.g. a diluent conventionally used in conjunction with odorants, such as diethyl phthalate (DEP), dipropylene glycol (DPG), isopropyl myristate (IPM), pentane-1,2-diol, triethyl citrate (TEC) and alcohol (e.g. ethanol). Optionally, the composition may comprise an anti-oxidant adjuvant. Said anti-oxidant may be selected from Tinogard TT (BASF), Tinogard Q (BASF), Tocopherol (including its isomers, CAS 59-02-9; 364-49-8; 18920-62-2; 121854-78-2), 2,6-bis(1,1-dimethylethyl)-4-methylphenol (BHT, CAS 128-37-0) and related phenols, hydroquinones (CAS 121-31-9).

[0066] The following list comprises examples of known odorant molecules, which may be combined with a compound of formula (I), or a mixture thereof: [0067] essential oils and extracts, e.g. castoreum, costus root oil, oak moss absolute, geranium oil, tree moss absolute, basil oil, fruit oils, such as bergamot oil and mandarine oil, myrtle oil, palmarose oil, patchouli oil, petitgrain oil, jasmine oil, rose oil, sandalwood oil, wormwood oil, lavender oil and/or ylang-ylang oil; [0068] alcohols, e.g. cinnamic alcohol ((E)-3-phenylprop-2-en-1-ol); cis-3-hexenol ((Z)-hex-3-en-1-ol); citronellol (3,7-dimethyloct-6-en-1-ol); dihydro myrcenol (2,6-dimethyloct-7-en-2-ol); Ebanol ((E)-3-methyl-5-(2,2,3-trimethylcyclopent-3-en-1-yl) pent-4-en-2-ol); eugenol (4-allyl-2-methoxyphenol); ethyl linalool ((E)-3,7-dimethylnona-1,6-dien-3-ol); farnesol ((2E,6Z)-3,7,11-trimethyldodeca-2,6,10-trien-1-ol); geraniol ((E)-3,7-dimethylocta-2,6-dien-1-ol); Super Muguet ((E)-6-ethyl-3-methyloct-6-en-1-ol); linalool (3,7-dimethylocta-1,6-dien-3-ol); menthol (2-isopropyl-5-methylcyclohexanol); Nerol (3,7-dimethyl-2,6-octadien-1-ol); phenyl ethyl alcohol (2-phenylethanol); Rhodinol (3,7-dimethyloct-6-en-1-ol); Sandalore (3-methyl-5-(2,2,3-trimethylcyclopent-3-en-1-yl)pentan-2-ol); terpineol (2-(4-methylcyclohex-3-en-1-yl)propan-2-ol); or Timberol (1-(2,2,6-trimethylcyclohexyl)hexan-3-ol); 2,4,7-trimethylocta-2,6-dien-1-ol, and/or [1-methyl-2(5-methylhex-4-en-2-yl)cyclopropyl]-methanol; [0069] aldehydes and ketones, e.g. anisaldehyde (4-methoxybenzaldehyde); alpha amyl cinnamic aldehyde (2-benzylideneheptanal); Georgywood (1-(1,2,8,8-tetramethyl-1,2,3,4,5,6,7,8-octahydronaphthalen-2-yl)ethanone); Hydroxycitronellal (7-hydroxy-3,7-dimethyloctanal); Iso E Super (1-(2,3,8,8-tetramethyl-1,2,3,4,5,6,7,8-octahydronaphthalen-2-yl)ethanone); Isoraldeine ((E)-3-methyl-4-(2,6,6-trimethylcyclohex-2-en-1-yl)but-3-en-2-one); Hedione (methyl 3-oxo-2-pentylcyclopentaneacetate); 3-(4-isobutyl-2-methylphenyl)propanal; maltol; methyl cedryl ketone; methylionone; verbenone; and/or vanillin; [0070] ether and acetals, e.g. Ambrox (3a,6,6,9a-tetramethyl-2,4,5,5a,7,8,9,9b-octahydro-1H-benzo [e][1]benzofuran); geranyl methyl ether ((2E)-1-methoxy-3,7-dimethylocta-2,6-diene); and/or Spirambrene (2,2,3,7,7-pentamethylspiro[bicyclo[4.1.0]heptane-2,5-[1,3]dioxane]); [0071] esters and lactones, e.g. benzyl acetate; cedryl acetate ((1S,6R,8aR)-1,4,4,6-tetramethyloctahydro-1H-5,8a-methanoazulen-6-yl acetate); delta-decalactone (6-pentyltetrahydro-2H-pyran-2-one); Helvetolide (2-(1-(3,3-dimethylcyclohexyl)ethoxy)-2-methylpropyl propionate); delta-undecalactone (5-heptyloxolan-2-one); and/or vetiveryl acetate ((4,8-dimethyl-2-propan-2-ylidene-3,3a,4,5,6,8a-hexahydro-1H-azulen-6-yl) acetate); [0072] macrocycles, e.g. Ambrettolide ((Z)-oxacycloheptadec-10-en-2-one); ethylene brassylate (1,4-dioxacycloheptadecane-5,17-dione); and/or Exaltolide (16-oxacyclohexadecan-1-one); and [0073] heterocycles, e.g. isobutylquinoline (2-isobutylquinoline).

[0074] Thus there is provided in a further aspect of the invention a fragrance composition comprising a compound of formula (I).

[0075] The compounds of formula (I) may be used in a broad range of fragranced articles, e.g. in any field of fine and functional perfumery, such as perfumes, air care products, household products, laundry products, body care products and cosmetics. The compound can be employed in widely varying amounts, depending upon the specific article and on the nature and quantity of other odorant ingredients. The proportion is typically from 0.00001 to 3 weight per cent of the article. In one embodiment, the compound may be employed in a fabric softener in an amount from 0.0001 to 3 weight per cent (e.g. 0.001 to 1 including 0.5, 0.3, and 0.05 weight %). In another embodiment, the compound may be used in fine perfumery in amounts from 0.01 to 30 weight per cent (e.g. up to about 10 or up to 20 weight per cent), more preferably between 0.01 and 5 weight per cent (e.g. 0.01 to 0.1 weight per cent). However, these values are given only by way of example, since the experienced perfumer may also achieve effects or may create novel accords with lower or higher concentrations.

[0076] The compounds of formula (I) may be employed in a consumer product base simply by directly mixing the compound, or a fragrance composition comprising a compound of formula (I), or a mixture thereof, with the consumer product base, or it may, in an earlier step, be entrapped with an entrapment material, for example, polymers, capsules, microcapsules and nanocapsules, liposomes, film formers, absorbents such as carbon or zeolites, cyclic oligosaccharides and mixtures thereof, and then mixed with the consumer product base.

[0077] Thus, the invention additionally provides a method of manufacturing a fragranced article, comprising the incorporation a compound of formula (I), or a mixture thereof as a fragrance ingredient, either by directly admixing to the consumer product base or by admixing a fragrance composition comprising a compound of formula (I), or a mixture thereof, which may then be mixed with a consumer product base, using conventional techniques and methods. Through the addition of an olfactory acceptable amount of a compound of formula (I), or a mixture thereof the odor notes of a consumer product base will be improved, enhanced, or modified.

[0078] Thus, the invention furthermore provides a method for improving, enhancing or modifying a consumer product base by means of the addition thereto of an olfactorily acceptable amount of a compound of formula (I), or a mixture thereof.

[0079] There is provided in a further aspect of the present invention a fragranced article comprising: [0080] a) a compound of formula (I)

##STR00004## [0081] wherein [0082] is indicating a carbon-carbon single or double bond, [0083] R is hydrogen and R.sup.1 is hydrogen or methyl, or [0084] R and R.sup.1 form together with the C-atom to which they are attached a vinyl group, [0085] R.sup.2 is selected from methyl and ethyl, [0086] R.sup.3 and R.sup.4 are hydrogen, or [0087] R.sup.3 and R.sup.4 together with the CC bond represent a double bond, or [0088] R.sup.2 and R.sup.3 form together a methylene group, [0089] R.sup.5 is selected from C.sub.5-C.sub.7 alkyl, and C.sub.5-C.sub.7 alkenyl, and [0090] R.sup.6 is selected from hydrogen and methyl; [0091] and [0092] b) a consumer product base.

[0093] As used herein, consumer product base means a composition for use as a consumer product to fulfill specific actions, such as cleaning, softening, and caring or the like. Examples of such products include fine perfumery, e.g. perfume and eau de toilette; fabric care, household products and personal care products such as cosmetics, laundry care detergents, rinse conditioner, personal cleansing composition, detergent for dishwasher, surface cleaner; laundry products, e.g. softener, bleach, detergent; body-care products, e.g. shampoo, shower gel; air care products (includes products that contain preferably volatile and usually pleasant-smelling compounds which advantageously can even in very small amounts mask unpleasant odors). Air fresheners for living areas contain, in particular, natural and synthetic essential oils such as pine needle oils, citrus oil, eucalyptus oil, lavender oil, and the like, in amounts for example of up to 50% by weight. As aerosols they tend to contain smaller amounts of such essential oils, by way of example less than 5% or less than 2% by weight, but additionally include compounds such as acetaldehyde (in particular, <0.5% by weight), isopropyl alcohol (in particular, <5% by weight), mineral oil (in particular, <5% by weight), and propellants.

[0094] Cosmetic products include: [0095] (a) cosmetic skincare products, especially bath products, skin washing and cleansing products, skincare products, eye makeup, lip care products, nail care products, intimate care products, foot care products; [0096] (b) cosmetic products with specific effects, especially sunscreens, tanning products, de-pigmenting products, deodorants, antiperspirants, hair removers, and shaving products; [0097] (c) cosmetic dental-care products, especially dental and oral care products, tooth care products, cleaners for dental prostheses, adhesives for dental prostheses; and [0098] (d) cosmetic hair care products, especially hair shampoos, hair care products, hair setting products, hair-shaping products, and hair coloring products.

[0099] This list of products is given by way of illustration, and is not to be regarded as being in any way limiting.

[0100] In one particular embodiment the consumer product base is selected form fine perfumery, and personal care products, including deodorants, hair care products, soaps, and the like. In one particular embodiment the consumer product base is a hair care product.

[0101] In a further particular embodiment the consumer product base is selected from fabric care products, including fabric softener, and home care products, including air fresheners, dish washers and the like.

[0102] Whereas certain compounds of formula (I) wherein R.sup.5 is selected from 3-methyl (butyl) and 3-methyl (but-2-enyl) are described in the literature as intermediates for the preparation of insect growth regulators (Liebigs Ann. Chem. 1986, 509-524), most are novel in their own right.

[0103] Thus there is provided in a further aspect of the invention a compound of formula (I)

##STR00005## [0104] wherein [0105] is indicating a carbon-carbon single or double bond, [0106] R is hydrogen and R.sup.1 is hydrogen or methyl, or [0107] R and R.sup.1 form together with the C-atom to which they are attached a vinyl group, [0108] R.sup.2 is selected from methyl and ethyl, [0109] R.sup.3 and R.sup.4 are hydrogen, or [0110] R.sup.3 and R.sup.4 together with the CC bond represent a double bond, or [0111] R.sup.2 and R.sup.3 form together a methylene group, [0112] R.sup.5 is selected from C.sub.5-C.sub.7 alkyl, and C.sub.5-C.sub.7 alkenyl, and [0113] R.sup.6 is selected from hydrogen and methyl; [0114] with the proviso that the compound is not a compound of formula (I) wherein R.sup.2 is methyl, R, R.sup.1, R.sup.3, R.sup.4 and R.sup.6 are hydrogen and R.sup.5 is selected from 3-methyl (but-2-enyl) and 3-methyl (butyl), and is not 3-methyl-2-(6-methylhepta-2,5-dien-2-yl)cyclopent-2-en-1-one.

[0115] The compounds of formula (I) wherein R is hydrogen and R.sup.1 is hydrogen or methyl may, for example, be synthesized by intramolecular aldol condensation of the respective diketone (III) under a base condition (e.g. NaOH) obtaining compounds of formula (I) wherein represents a carbon-carbon double bond, optionally followed by hydrogenation to obtain compounds of formula (I) wherein represents a carbon-carbon single bond, as depicted below.

##STR00006##

[0116] Preparation of the diketones (III) is well known in the art. It may be done, e.g. by 1,4 addition reaction (e.g. Stetter reaction) of the respective aldehyde with the respective , -unsaturated ketone in a base condition (e.g. Cs.sub.2CO.sub.3, TEA, sodium L-ascorbate) catalyzed by a thiazolium salt (e.g. thiamine hydrochloride, 3-Ethyl-5-(2-hydroxyethyl)-4-methylthiazolium bromide).

[0117] When following this procedure as described above, one may obtain a mixture comprising compounds of formula (I) and compounds of formula (II)

##STR00007## [0118] wherein [0119] R.sup.1 is hydrogen or methyl, [0120] R.sup.2 is selected from methyl and ethyl, [0121] R.sup.3 and R.sup.4 are hydrogen, or [0122] R.sup.3 and R.sup.4 together with the CC bond represent a double bond, or [0123] R.sup.2 and R.sup.3 form together a methylene group, [0124] R.sup.5 is selected from C.sub.5-C.sub.7 alkyl, and C.sub.5-C.sub.7 alkenyl, and [0125] R.sup.6 is selected from hydrogen and methyl.

[0126] Thus there is provided in a further aspect of the present invention the use as fragrance or flavor of a mixture comprising a compound of formula (I) and a compound of formula (II)

##STR00008## [0127] wherein [0128] R is hydrogen, [0129] R.sup.1 is hydrogen or methyl, [0130] R.sup.2 is selected from methyl and ethyl, [0131] R.sup.3 and R.sup.4 are hydrogen, or [0132] R.sup.3 and R.sup.4 together with the CC bond represent a double bond, or [0133] R.sup.2 and R.sup.3 form together a methylene group, [0134] R.sup.5 is selected from C.sub.5-C.sub.7 alkyl, and C.sub.5-C.sub.7 alkenyl, and [0135] R.sup.6 is selected from hydrogen and methyl.

[0136] In a further aspect of the present invention there is provide a fragrance composition or a fragranced article comprising a mixture comprising a compound of formula (I) and a compound of formula (II), e.g., in a ratio of 99:1 to about 1:99, such as about 90:10 to about 10:90, which includes a ratio of 80:20 to 20:80, 70:30 to 30:70, 95:5 to 85:15.

[0137] Alternatively, the compounds of formula (I) may, for example, be synthesized by in situ addition of 1,3-cyclopentanone with the respective ketone followed by reduction using diethyl 2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate catalyzed by proline. To the thus formed diketone, methanol is added under acidic conditions to form the respective 3-methoxy cyclopentenone derivatives, followed by a Grignard reaction working up under acid conditions.

[0138] The invention is now further described with reference to the following non-limiting examples. These examples are for the purpose of illustration only and it is understood that variations and modifications can be made by one skilled in the art.

Example 1-1: 3-methyl-2-(oct-5-en-2-yl)cyclopent-2-en-1-one

[0139] a) A suspension of 3-methylnona-2,6-dienal (11.0 g, 72 mmol) Lindlar Pd (Palladium, 5% on calcium carbonate, lead poisoned, 0.5 g) and potassium carbonate (10.0 g, 72 mmol) in ethyl estate was stirred under H.sub.2 for 28 h. The mixture was filtered through a short silica gel pad, the solvent was removed and the residue oil was purified by column chromatography on silica gel to get 3-methylnon-6-enal (9.0 g, 58 mmol, yield: 81%, E/Z=9:1) as a light yellow oil. [0140] b) A suspension of triethylamine (2.9 g, 29 mmol) and 3-ethyl-5-(2-hydroxyethyl)-4-methylthizolium bromide (2.9 g, 12 mmol) in ethanol (80 mL) was stirred at room temperature for 10 min, and then but-3-en-2-one (8.2 g, 117 mmol) and 3-methylnon-6-enal (9.0 g, 58 mmol) were added. The mixture was refluxed under argon overnight. Water (80 mL) was added, and extracted with MTBE (80 mL*2). The solvent was removed and the residue oil was purified by column chromatography on silica gel to get 7-methyltridec-10-ene-2,5-dione (9.2 g, 41 mmol, yield: 71%, E:Z=9:1) as a light yellow oil. [0141] c) A solution of 7-methyltridec-10-ene-2,5-dione (8.7 g, 38.8 mmol) in ethanol (80 mL) was added an aqueous NaOH solution (0.5 M, 80 mL), the result solution was heated to reflux overnight. MTBE (50 mL*2) was used to extract the solution, the solvent was removed and the residue oil was purified by column chromatography on silica gel to get 3-methyl-2-(oct-5-en-2-yl)cyclopent-2-en-1-one (5.2 g, 25 mmol, yield: 64%, E/Z isomers, E/Z=9:1) as a colorless oil, and 3-(2-methyloct-5-en-1-yl)cyclopent-2-en-1-one (170 mg, 0.8 mmol, yield: 2%, E:Z=6:1) as a colorless oil. [0142] 3-methyl-2-(oct-5-en-2-yl)cyclopent-2-en-1-one: [0143] .sup.1H NMR (400 MHz, CDCl.sub.3) =5.48-5.20 (m, 2H), 2.74-2.53 (m, 1H), 2.48-2.44 (m, 2H), 2.38-2.25 (m, 2H), 2.04 (s, 3H), 2.01-1.91 (m, 2H), 1.90-1.45 (m, 4H), 1.18-1.09 (m, 3H), 0.94 (t, J=7.5 Hz, 3H) ppm. .sup.13C NMR (101 MHz, CDCl.sub.3, E isomer) =209.5, 169.8, 143.4, 132.1, 129.0, 34.6, 34.0, 31.8, 31.1, 29.8, 25.6, 18.5, 17.5, 13.9 ppm. GC/MS (EI): m/z (%): 206 (11) [M.sup.+], 191 (5), 177 (3), 150 (18), 124 (100), 109 (22), 67 (21), 55 (19). [0144] Odour description: peppery, woody, floral, fruity, green [0145] 3-(2-methyloct-5-en-1-yl)cyclopent-2-en-1-one: [0146] .sup.1H NMR (400 MHz, CDCl.sub.3, mixture of isomers) =5.94 (s, 1H), 5.54-5.29 (m, 2H), 2.66-1.15 (m, 13H), 1.05-0.86 (m, 6H) ppm. .sup.13C NMR (101 MHz, CDCl.sub.3) =210.1, 210.1, 182.1, 182.0, 132.4, 132.0, 130.6, 128.6, 128.5, 41.1, 41.0, 36.9, 36.7, 35.3, 31.7, 31.0, 30.9, 29.9, 25.5, 24.5, 20.5, 19.6, 14.3, 13.9 ppm. GC/MS (EI): m/z (%): 206 (3) [M.sup.+], 191 (5), 177 (3), 163 (4), 149 (14), 123 (100), 110 (61), 96 (35). [0147] Odour description: green, metallic, marine, oyster, oily.

Example 1-2: 3-methyl-2-(6-methylhept-5-en-2-yl)cyclopent-2-en-1-one

[0148] Following the general procedure of Example 1-1, a mixture of 3-methyl-2-(6-methylhept-5-en-2-yl)cyclopent-2-en-1-one and 3-(2,6-dimethylhept-5-en-1-yl)cyclopent-2-en-1-one were obtained from 7,11-dimethyldodec-10-ene-2,5-dione (5.0 g, 22.3 mmol) and sodium hydroxide (0.9 g, 22.3 mmol). 3-Methyl-2-(6-methylhept-5-en-2-yl)cyclopent-2-en-1-one is a colorless liquid (17.4 mmol, 3.6 g, 78% yield) and 3-(2,6-dimethylhept-5-en-1-yl)cyclopent-2-en-1-one is colorless liquid (1.9 mmol, 0.4 g, 9% yield). [0149] 3-Methyl-2-(6-methylhept-5-en-2-yl)cyclopent-2-en-1-one: [0150] .sup.1H NMR (400 MHz, CDCl.sub.3) =5.15-4.96 (t, J=5.6 Hz, 1H), 2.71-2.52 (m, 1H), 2.50-2.41 (m, 2H), 2.34-2.30 (m, 2H), 2.04 (s, 3H), 1.94-1.69 (m, 3H), 1.66 (s, 3H), 1.58-1.43 (m, 4H), 1.14 (d, J=7.1 Hz, 3H) ppm. .sup.13C NMR (101 MHz, CDCl.sub.3) =209.5, 169.8, 143.4, 131.3, 124.6, 34.6, 34.2, 31.7, 29.9, 26.6, 25.7, 18.6, 17.6, 17.4 ppm. GC/MS (EI): m/z (%): 206 (22) [M.sup.+], 191 (3), 150 (15), 137 (21), 124 (100), 109 (23), 67 (22). [0151] Odour description: woody, peppery, green, floral [0152] 3-(2,6-dimethylhept-5-en-1-yl)cyclopent-2-en-1-one: [0153] .sup.1H NMR (400 MHz, CDCl.sub.3) =5.94 (s, 1H), 5.10-5.06 (t, J=5.1 Hz, 1H), 2.66-1.74 (m, 9H), 1.69 (s, 3H), 1.61 (s, 3H), 1.39-1.20 (m, 2H), 0.92 (d, J=6.6 Hz, 3H) ppm. .sup.13C NMR (101 MHz, CDCl.sub.3) =210.1, 182.1, 131.7, 130.7, 124.2, 41.1, 36.9, 35.4, 31.7, 31.1, 25.7, 25.4, 19.7, 17.7 ppm. GC/MS (EI): m/z (%): 206 (4) [M.sup.+], 191 (3), 149 (7), 123 (100), 96 (36). [0154] Odour description: green, citronellic, waxy

Example 1-3: 3-methyl-2-(6-methylocta-2,5-dien-2-yl)cyclopent-2-en-1-one and 3-methyl-2-(6-methylocta-1,5-dien-2-yl)cyclopent-2-en-1- one

[0155] Following the general procedure described in Example 1-1, 7,11-Dimethyltrideca-6,10-diene-2,5-dione was obtained from 3,7-dimethylnona-2,6-dienal (10.0 g, 60.2 mmol) and but-3-en-2-one (4.2 g, 60.2 mmol) as light yellow liquid (13.1 mmol, 3.1 g, 22% yield). A mixture of 3-methyl-2-(6-methylocta-1,5-dien-2-yl)cyclopent-2-en-1-one and 3-methyl-2-(6-methylocta-2,5-dien-2-yl)cyclopent-2-en-1-one were obtained from 7,11-dimethyltrideca-6,10-diene-2,5-dione (3.0 g, 12.7 mmol) and sodium hydroxide (0.5 g, 12.7 mmol). 3-Methyl-2-(6-methylocta-1,5-dien-2-yl)cyclopent-2-en-1-one is colorless liquid (2.4 mmol, 0.5 g, 19% yield, two isomers: 5:7) and 3-methyl-2-(6-methylocta-2,5-dien-2-yl)cyclopent-2-en-1-one is colorless liquid (0.7 g, 3.3 mmol, 26% yield, 4 isomers). [0156] 3-methyl-2-(6-methylocta-1,5-dien-2-yl)cyclopent-2-en-1-one: [0157] .sup.1H NMR (400 MHz, CDCl.sub.3, mixture of isomers) =5.20 (s, 1H), 5.11-4.98 (m, 1H), 4.79 (s, 1H), 2.60-2.29 (m, 6H), 2.08 (s, 3H), 2.05-1.89 (m, 4H), 1.65, 1.55 (s, 3H), 1.00-0.89 (m, 3H) ppm. .sup.13C NMR (101 MHz, CDCl.sub.3, mixture of isomers) =207.9, 207.9, 171.5, 142.2, 142.2, 141.8, 141.7, 137.2, 137.0, 123.5, 122.3, 115.6, 35.5, 35.3, 34.6, 32.2, 31.7, 26.3, 26.0, 24.7, 22.8, 18.0, 18.0, 15.9, 12.7 ppm. GC/MS (EI): m/z (%): 218 (3) [M.sup.+], 189 (8), 161 (96), 121 (29), 91 (51), 55 (100). [0158] Odour description: woody, peppery, fruity [0159] 3-methyl-2-(6-methylocta-2,5-dien-2-yl)cyclopent-2-en-1-one: [0160] .sup.1H NMR (400 MHz, CDCl.sub.3, mixture of isomers) =5.47-4.81 (m, 2H), 2.83-2.24 (m, 6H), 2.05-1.41 (m, 11H), 0.96-0.73 (m, 3H) ppm. GC/MS (EI): m/z (%): 218 (16) [M.sup.+], 203 (11), 189 (15), 161 (34), 121 (29), 148 (58), 123 (52), 91 (100). [0161] Odour description: woody, fatty, green, floral, woody.

Example 1-4: 3-methyl-2-(6-methyloct-5-en-2-yl)cyclopent-2-en-1-one

[0162] Following the general procedure described in Example 1-1, [0163] a) 7,11-dimethyltridec-10-ene-2,5-dione (E/Z=4:3) was obtained from 3,7-dimethylnon-6-enal (14.5 g, 86.2 mmol) and but-3-en-2-one (30.2 g, 430.8 mmol) as light yellow liquid (8.1 mmol, 1.9 g, 9% yield, E/Z=4:3). [0164] b) 3-Methyl-2-(6-methyloct-5-en-2-yl)cyclopent-2-en-1-one was obtained from 7,11-dimethyltridec-10-ene-2,5-dione (1.8 g, 7.4 mmol) and sodium hydroxide (0.3 g, 7.4 mmol) as colorless liquid (3.1 mmol, 0.7 g, 42% yield, E/Z=4:3). [0165] .sup.1H NMR (400 MHz, CDCl.sub.3, mixture of E/Z isomers) =5.08-5.01 (m, 1H), 2.65-2.59 (m, 1H), 2.47-2.45 (m, 2H), 2.33-2.31 (m, 2H), 2.04 (s, 3H), 1.98-1.69 (m, 5H), 1.65, 1.54 (s, 3H), 1.58-1.44 (m, 1H), 1.15-1.13 (m, 3H), 0.98-0.91 (m, 3H) ppm. .sup.13C NMR (101 MHz, CDCl.sub.3, mixture of E/Z isomers) =209.5, 209.5, 169.7, 143.5, 137.1, 137.1, 136.8, 136.8, 124.2, 124.2, 123.0, 123.0, 34.6, 34.6, 34.3, 32.3, 31.7, 29.9, 29.9, 26.4, 26.1, 24.7, 22.9, 18.6, 17.5, 17.4, 15.9, 12.8 ppm. GC/MS (EI): m/z (%): E isomer: 220 (11) [M.sup.+], 205 (2), 191 (1), 150 (10), 137 (21), 124 (100), 109 (21), 55 (44); Z isomer: 220 (9) [M.sup.+], 205 (1), 191 (1), 150 (11), 137 (22), 124 (100), 109 (21), 55 (43). [0166] Odour description: woody, peppery, waxy, green

Example 1-5: 3-methyl-2-(octa-2,5-dien-2-yl)cyclopent-2-en-1-one and 3-methyl-2-(octa-1,5-dien-2-yl)cyclopent-2-en-1-one

[0167] Following the general procedure described in Example 1-1, [0168] a) 7-methyltrideca-6,10-diene-2,5-dione was obtained from 3-methylnona-2,6-dienal (15.5 g, 101.8 mmol) and but-3-en-2-one (14.3 g, 203.6 mmol) as light yellow liquid (2.9 g, 13.0 mmol, 13% yield). [0169] b) A mixture of 3-methyl-2-(octa-2,5-dien-2-yl)cyclopent-2-en-1-one and 3-methyl-2-(octa-1,5-dien-2-yl)cyclopent-2-en-1-one was obtained from 7-methyltrideca-6,10-diene-2,5-dione (400 mg, 1.8 mmol) and sodium hydroxide (72 mg, 1.8 mmol). 3-Methyl-2-(octa-2,5-dien-2-yl)cyclopent-2-en-1-one is a colorless liquid (71 mg, 19% yield, mixture of isomers) and 3-methyl-2-(octa-1,5-dien-2-yl)cyclopent-2-en-1-one is a colorless liquid (68 mg, 18% yield, mixture of isomers, E/Z=8:1). [0170] 3-Methyl-2-(octa-2,5-dien-2-yl)cyclopent-2-en-1-one (mixture of isomers): [0171] .sup.1H NMR (400 MHz, CDCl.sub.3, mixture of isomers) 5.64-5.11 (m, 3H), 2.91-2.35 (m, 6H), 2.11-1.92 (m, 5H), 1.85-1.76 (m, 3H), 1.02-0.89 (m, 3H). GC/MS (EI): m/z (%): 204 (31) [M.sup.+], 189 (20), 175 (35), 161 (35), 147 (55), 135 (55), 119 (55), 105 (70), 91 (100), 77 (70). [0172] Odour description: woody, oily green floral, fruity (peach) [0173] 3-Methyl-2-(octa-1,5-dien-2-yl)cyclopent-2-en-1-one (mixture of isomers, E/Z=8:1): [0174] .sup.1H NMR (400 MHz, CDCl.sub.3, mixture of E/Z) 5.44-5.23 (m, 2H), 5.17-5.08 (m, 1H), 4.81-4.65 (m, 1H), 2.48 (br d, J=4.1 Hz, 2H), 2.42-2.24 (m, 4H), 2.12-1.84 (m, 7H), 0.87 (t, J=7.4 Hz, 3H) ppm. .sup.13C NMR (400 MHz, CDCl.sub.3, E isomer) 208.0, 171.5, 142.3, 141.5, 132.3, 128.3, 115.7, 35.2, 34.6, 31.7, 30.9, 25.5, 18.0, 13.8 ppm. GC/MS (EI): m/z (%): 204 (20) [M.sup.+], 189 (18), 175 (45), 161 (100), 147 (45), 135 (50), 121 (45), 91 (95), 77 (80). [0175] Odour description: woody, peppery, green floral, fruity

Example 1-6: 3-methyl-2-(nonan-2-yl)cyclopent-2-en-1-one

[0176] a) 3-Methyldeca-2,6-dienal was prepared from 1,1-diethoxy-3-methylbut-2-ene (70.0 g, 389 mmol) and hex-2-en-1-ol (50.7 g, 506 mmol) according to the procedure reported in literature (Helv. Chim. Acta 2017, 100, e1700200) as colorless liquid (33.3 g, 200 mmol, 51% yield). [0177] b) Following the general procedure described in Example 1-1 (step b), 7-methyltetradeca-6,10-diene-2,5-dione was obtained from 3-methyldeca-2,6-dienal (30.0 g, 180 mmol) and but-3-en-2-one (25.3 g, 361 mmol) as light yellow liquid (6.8 g, 29.0 mmol, 16% yield). [0178] c) 7-methyltetradeca-6,10-diene-2,5-dione (4.4 g, 18.6 mmol, 1.0 equiv) and Pd/C (10%, 200 mg) in methanol (50 mL) was hydrogenated for 16h and give 7-methyltetradecane-2,5-dione as light yellow liquid (3.5 g, 14.6 mmol, 78% yield). [0179] d) Following the general procedure described in Example 1-1 (step c), 3-methyl-2-(nonan-2-yl)cyclopent-2-en-1-one was obtained from 7-methyltetradecane-2,5-dione (3.4 g, 14.1 mmol) and sodium hydroxide (0.6 g, 14.1 mmol as colourless liquid (7.3 mmol, 1.6 g, 51% yield). [0180] .sup.1H NMR (400 MHz, CDCl.sub.3) =2.67-2.52 (m, 1H), 2.50-2.40 (m, 2H), 2.36-2.25 (m, 2H), 2.05 (s, 3H), 1.69-1.65 (m, 1H), 1.54-1.40 (m, 1H), 1.32-1.10 (m, 14H), 0.87 (t, J=6.9 Hz, 3H) ppm. .sup.13C NMR (101 MHz, CDCl.sub.3) =209.4, 169.4, 143.7, 34.5, 34.3, 31.9, 31.7, 30.3, 29.6, 29.3, 28.2, 22.6, 18.6, 17.5, 14.1 ppm. GC/MS (EI): m/z (%): 222 (17) [M.sup.+], 207 (100), 193 (6), 151 (23), 137 (46), 124 (97). [0181] Odour description: peppery, woody, green, metallic, rooty, jasmone, fenugreek.

Example 1-7: 3-methyl-2-(non-5-en-2-yl)cyclopent-2-en-1-one

[0182] Following the general procedure described in Example 1-1, [0183] a) 3-methyldec-6-enal was obtained from 3-methyldeca-2,6-dienal (5.6 g, 33.7 mmol) as colorless liquid (30.0 mmol, 5.0 g, 80% yield, E/Z isomers, E/Z=6:1). [0184] b) 7-methyltetradec-10-ene-2,5-dione was obtained from 3-methyldec-6-enal (4.9 g, 29.1 mmol) and but-3-en-2-one (4.1 g, 58.2 mmol) as light yellow liquid (17.0 mmol, 4.1 g, 59% yield, E/Z isomers, E/Z=3:1). [0185] c) The title compound was obtained from 7-methyltetradec-10-ene-2,5-dione (4.0 g, 16.8 mmol) and sodium hydroxide (0.7 g, 16.8 mmol) as colorless liquid (1.3 g, 6.0 mmol, 36% yield, mixture of E/Z isomers: E/Z=10:1). [0186] .sup.1H NMR (400 MHz, CDCl.sub.3, mixture of E/Z isomers) =5.47-5.26 (m, 2H), 2.68-2.54 (m, 1H), 2.51-2.43 (m, 2H), 2.35-2.28 (m, 2H), 2.05, 2.04 (s, 3H), 1.98-1.72 (m, 5H), 1.62-1.48 (m, 1H), 1.41-1.27 (m, 2H), 1.17-1.10 (m, 3H), 0.92-0.84 (m, 3H) ppm. .sup.13C NMR (101 MHz, CDCl.sub.3, mainly Z isomer) =209.4, 169.7, 143.4, 130.3, 130.2, 129.8 (Z), 129.7 (Z), 34.7, 34.6, 34.0, 31.7, 31.1, 29.8, 22.7, 18.5, 17.5, 13.6 ppm. GC/MS (EI): m/z (%): 220 (8) [M.sup.+], 205 (3), 177 (2), 150 (16), 124 (100), 55 (27). [0187] Odour description: woody, green, metallic, rooty, jasmone, fenugreek, peppery, pepperwood

Example 1-8: 3,4-dimethyl-2-(6-methylhept-5-en-2-yl)cyclopent-2-en-1-one

[0188] Following the general procedure described in Example 1-1, [0189] a) 3,7,11-trimethyldodec-10-ene-2,5-dione was obtained from 3,7-dimethyloct-6-enal (10.0 g, 64.8 mmol) and 3-methylbut-3-en-2-one (8.2 g, 97.2 mmol) as light yellow liquid (17.0 mmol, 4.1 g, 27% yield, mixture of isomers: 1:1). [0190] b) 3,4-dimethyl-2-(6-methylhept-5-en-2-yl)cyclopent-2-en-1-one was obtained from 3,7,11-trimethyldodec-10-ene-2,5-dione (4.0 g, 16.8 mmol) and sodium hydroxide (0.7 g, 16.8 mmol) as colorless liquid (10.0 mmol, 2.3 g, 62% yield, mixture of isomers: 1:1). [0191] .sup.1H NMR (400 MHz, CDCl.sub.3 mixture of isomers) =5.07 (t, J=9.8 Hz, 1H), 2.74-2.45 (m, 3H), 2.02-1.96 (m, 3H), 1.96-1.69 (m, 4H), 1.68-1.63 (m, 3H), 1.57-1.46 (m, 4H), 1.19-1.10 (m, 6H) ppm. .sup.13C NMR (101 MHz, CDCl.sub.3, mixture of isomers) =208.5, 208.5, 173.8, 173.7, 142.9, 142.8, 131.3, 131.3, 124.6, 124.6, 43.5, 43.4, 37.2, 34.2, 34.2, 30.1, 29.9, 26.6, 26.5, 25.7, 19.0, 17.7, 17.6, 15.0, 14.9 ppm. GC/MS (EI): m/z (%): 220 (46) [M.sup.+], 205 (2), 177 (5), 164 (8), 151 (20), 138 (82), 123 (100). [0192] Odour description: green, mushroom, milky, woody, cedarwood.

Example 2-1: 3-methyl-2-(5-methylhept-4-en-2-yl)cyclopent-2-en-1-one

[0193] a) A solution of 2-methylfuran (7.4 g, 90.0 mmol) in THF (100 mL) was added butyllithium (75 mmol, 1.6 M in hexane, 50 mL) dropwise at 78 C., and stirred for another hour, and then the reaction solution was warmed up and stirred at r.t. for 4 h. Cool down to 78 C., and 2,5-dimethylhept-4-enal (9.5 g, 67.5 mmol) was added dropwise. The mixture was allowed to warm to rt. in 1 hour after addition and stirred at rt. overnight. The reaction was quenched by diluted NH.sub.4Cl solution (150 mL) at 0 C., and extracted by MTBE (100 mL*2). The combined organic phase was dried over MgSO.sub.4, the solvent was removed by rotary evaporation and the residue oil was purified by column chromatography on silica gel to get 2,5-dimethyl-1-(5-methylfuran-2-yl) hept-4-en-1-ol (10.7 g, 48 mmol, yield: 71%) [0194] b) To a solution of 2,5-dimethyl-1-(5-methylfuran-2-yl) hept-4-en-1-ol (10.5 g, 47.2 mmol) in DCE (200 mL) was added zinc (II) iodide (22.6 g, 70.8 mmol) and sodium cyanoborohydride (22.3 g, 354.2 mmol) at 10 C. The result mixture was stirred at rt. for 1 h. MTBE (200 mL) was used to dilute the reaction mixture, the whole mixture was filtered, and the solvent was removed by rotary evaporation and the residue oil was purified by column chromatography on silica gel to get 2-(2,5-dimethylhept-4-en-1-yl)-5-methylfuran (5.6 g, 27 mmol, yield: 58%, mixture of E/Z isomers, E/Z=7:5) as a colorless liquid. [0195] c) The mixture of 2-(2,5-dimethylhept-4-en-1-yl)-5-methylfuran (5.5 g, 26.7 mmol) and acetic acid (24.0 g, 399.8 mmol) was added 0.2 g con. H.sub.2SO.sub.4. The result solution was heated to reflux for 3 h. Cool down to room temperature and water (50 mL) was added. The result solution was extracted by MTBE (50 mL*2), the combined organic solution was washed with sat. NaHCO.sub.3 solution (30 mL) and brine (20 mL), and dried over MgSO.sub.4. Remove the solvent by rotary evaporation, and the residue oil was purified by column chromatography on silica gel to get 7,10-dimethyldodec-9-ene-2,5-dione and 7,10-dimethyldodec-10-ene-2,5-dione (3.3 g, 14 mmol, 54%) as a brown liquid. [0196] d) A solution of 7,10-dimethyldodec-9-ene-2,5-dione and 7,10-dimethyldodec-10-ene-2,5-dione (2.0 g, 8.9 mmol) and sodium hydroxide (0.4 g, 8.9 mmol) in ethanol (60 mL) was heated to reflux overnight. Cool to room temperature, and water (30 mL) was added, extract by MTBE (60 mL*2), remove the solvent by rotary evaporation and the residue oil was purified by column chromatography on silica gel to get 3-methyl-2-(5-methylhept-4-en-2-yl)cyclopent-2-en-1-one and 3-methyl-2-(5-methylhept-5-en-2-yl)cyclopent-2-en-1-one (1.3 g, 6.1 mmol, yield: 69%) as a colorless oil. [0197] GC/MS (EI): m/z (%): 206 (19) [M.sup.+], 178 (2), 164 (8), 136 (8), 124 (100), 109 (10), 95 (9), 83 (19), 67 (18), 55 (48) ppm. [0198] Odour description: woody, green, rooty, jasmone, aromatic, coniferous, piney.

Example 2-2: 3-methyl-2-(5-methylheptan-2-yl)cyclopent-2-en-1-one

[0199] a) 7,10-dimethyldodecane-2,5-dione was obtained via hydrogenation of 7,10-dimethyldodec-9-ene-2,5-dione and 7,10-dimethyldodec-10-ene-2,5-dione (1.0 g, 4.4 mmol) catalyzed by Pd/C (10%, 100 mg) in EA (50 mL) as light yellow liquid (0.9 g, 3.9 mmol, 88% yield, mixture of isomers, 1:1). [0200] b) Following the general procedure described in Example 2-1 (step d), 3-methyl-2-(5-methylheptan-2-yl)cyclopent-2-en-1-one was obtained from 7,10-dimethyldodecane-2,5-dione (0.9 g, 4.0 mmol) and sodium hydroxide (0.2 g, 4.0 mmol) as colorless liquid (1.5 mmol, 0.3 g, 39% yield, mixture of isomers: 1:1). [0201] .sup.1H NMR (400 MHz, CDCl.sub.3, mixture of two isomers) =2.58-2.52 (m, 1H), 2.49-2.45 (m, 2H), 2.36-2.27 (m, 2H), 2.05 (s, 3H), 1.77-1.37 (m, 2H), 1.37-0.80 (m, 14H) ppm. .sup.13C NMR (101 MHz, CDCl.sub.3, mixture of two isomers) =209.5, 169.5, 169.5, 143.8, 143.7, 35.1, 35.0, 34.5, 34.4, 34.4, 31.8, 31.7, 31.7, 30.6, 30.5, 29.5, 29.3, 19.3, 19.2, 18.7, 18.6, 17.5, 11.4, 11.3 ppm. GC/MS (EI): m/z (%): 208 (5) [M.sup.+], 193 (19), 179 (5), 151 (42), 125 (100), 109 (31), 79 (29). [0202] Odour description: woody, green, rooty, jasmony, waxy.

Example 3: 2-(4,7-dimethyloct-6-en-2-yl)-3-methylcyclopent-2-en-1-one

[0203] a) To a solution of 2-methylfuran (5.0, 60.9 mmol) in THF (100 mL) was added butyllithium (60.9 mmol, 38 mL, 1.6M in hexane) dropwise over 30 min at 78 C. And after 1 h, the solution was warmed up to rt. and stirred overnight. Then 8-bromo-2,5,7-trimethyloct-2-ene (12.9 g, 55.4 mmol) was added dropwise at 0 C., and then the mixture was stirred at rt. overnight. Water (60 mL) was added to quench the reaction, the mixture was extracted by MTBE (50 mL*2), and the combined organic phase was dried over MgSO.sub.4. The solvent was removed, and the residue was purified by column chromatography on silica gel to get 2-methyl-5-(2,4,7-trimethyloct-6-en-1-yl) furan (6.7 g, 29.0 mmol, yield: 52%) as a light yellow liquid. [0204] b) A solution of 2-methyl-5-(2,4,7-trimethyloct-6-en-1-yl) furan (6.0 g, 25.6 mmol) in 36 mL 75% acetic acid solution (75 g acetic acid and 25 g water and 0.6 g con.H.sub.2SO.sub.4), and then the mixture was heated to reflux for 3 h. After it was cooled to room temperature, water (50 mL) was added, the solution was extracted by MTBE (50 mL*3), and the organic layer was washed with sat. NaHCO.sub.3 solution (20 mL). The solvent was removed by rotary evaporation and the residue oil was purified by column chromatography on silica gel to get 7,9, 12-trimethyltridec-11-ene-2,5-dione (3.5 g, 14.0 mmol, yield: 54%, mixture of two isomers, 1:1) as a light yellow liquid. [0205] c) A solution of 7,9,12-trimethyltridec-11-ene-2,5-dione (3.5 g, 14.0 mmol) and aqueous sodium hydroxide solution (0.6 g, 14.0 mmol) in ethanol (28 mL) was heated to reflux overnight. Water (70 mL) was added to the cooled reaction mixture, MTBE (50 mL*2) was used to extract the solution, the solvent was removed by rotary evaporation and the residue oil was purified by column chromatography on silica gel to get 2-(4,7-dimethyloct-6-en-2-yl)-3-methylcyclopent-2-en-1-one (1.9 g, 8.1 mmol, 58%) as a colorless oil. [0206] .sup.1H NMR (400 MHz, CDCl.sub.3, mixture of two isomers) =5.19-4.97 (m, 1H), 2.87-2.64 (m, 1H), 2.54-2.38 (m, 2H), 2.36-2.26 (m, 2H), 2.05 (s, 3H), 2.01-1.04 (m, 14H), 0.85-0.80 (m, 3H) ppm. .sup.13C NMR (101 MHz, CDCl.sub.3, mixture of two isomers) =209.5, 209.5, 169.5, 169.2, 144.1, 143.5, 132.0, 132.0, 123.3, 123.1, 41.3, 41.3, 35.8, 35.0, 34.6, 34.5, 32.0, 31.7, 31.7, 31.7, 27.7, 27.7, 25.8, 25.8, 19.7, 19.4, 19.3, 18.5, 17.8, 17.8, 17.5 ppm. GC/MS (EI): m/z (%): 234 (10) [M.sup.+], 219 (4), 165 (22), 123 (100), 110 (59), 67 (28), 55 (30). [0207] Odour description: woody, green, metallic, fatty, rooty, jasmone, peach, floral, -ionone.

Example 4-1: 2-(6-methylhept-5-en-2-yl)-3-vinylcyclopent-2-en-1-one

[0208] a) A mixture of cyclopentane-1,3-dione (20.0 g, 204 mmol), L-proline (1.76 g,15 mmol), diethyl 2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate (56.8 g, 224 mmol) and 6-methylhept-5-en-2-one (38.6 g, 306 mmol) in 1,2-dichloroethane (200 mL) was heated to reflux for 48 h. The solvent was removed by rotary evaporation, and the residue was purified by column chromatography on silica gel to get 3-hydroxy-2-(6-methylhept-5-en-2-yl)cyclopent-2-en-1-one (21.0 g, 101 mmol, yield: 49%) as a light yellow solid. [0209] b) A mixture of 2-(6-methylhept-5-en-2-yl)cyclopentane-1,3-dione (8.60 g, 41 mmol), methanol (39.7 g) and 4-methylbenzenesulfonic acid hydrate (0.78 g, 4 mmol) in toluene (150 mL) was refluxed in the presence of a dean-stark to remove water overnight. The mixture was concentrated by rotary evaporation, and the residue was purified by column chromatography on silica gel to get 3-methoxy-2-(6-methylhept-5-en-2-yl)cyclopent-2-en-1-one (7.2 g, 32 mmol, yield: 78%) as a colorless liquid. [0210] c) To a solution of vinylmagnesium bromide (1M in THF, 40 mL) was added 3-methoxy-2-(6-methylhept-5-en-2-yl)cyclopent-2-en-1-one (3.0 g, 13 mmol) in THF (80 mL) dropwise at 0 C. The resulting mixture was stirred at rt. for 3 h. 1.6 M HCl solution (100 mL) was added to quench the reaction at 0 C. The mixture was stirred at rt. for 2 h and extracted with MTBE (50 mL*2). The organic layer was dried over MgSO.sub.4, the solvent was removed and the residue oil was purified by column chromatography on silica gel to get 2-(6-methylhept-5-en-2-yl)-3-vinylcyclopent-2-en-1-one (1.5 g, 6.9 mmol, 53%) as a colorless liquid. [0211] .sup.1H NMR (400 MHz, CDCl.sub.3) =6.97 (dd, J=10.8, 17.4 Hz, 1H), 5.72 (dd, J=1.1, 17.3 Hz, 1H), 5.47 (dd, J=1.0, 10.8 Hz, 1H), 5.06-5.02 (m, 1H), 2.80-2.71 (m, 1H), 2.65-2.61 (m, 2H), 2.47-2.31 (m, 2H), 1.90-1.72 (m, 3H), 1.69-1.60 (m, 3H), 1.60-1.45 (m, 4H), 1.18 (d, J=7.0 Hz, 3H) ppm. .sup.13C NMR (101 MHz, CDCl.sub.3) =209.5, 163.3, 144.5, 131.4, 131.3, 124.4, 120.6, 34.3, 34.1, 29.9, 26.5, 25.7, 24.8, 18.9, 17.6 ppm. [0212] Odour description: peppery, woody, green, metallic, fresh citrus, linalool, bergamot.

Example 4-2: 3-ethyl-2-(6-methylhept-5-en-2-yl)cyclopent-2-en-1-one

[0213] Following the general procedure described in Example 4-1, the title compound was obtained from 3-methoxy-2-(6-methylhept-5-en-2-yl)cyclopent-2-en-1-one (3.0 g, 13.5 mmol) and ethylmagnesium bromide (20 mL, 1.0 M) as colorless liquid (0.5 g, 2.0 mmol, 20% yield). [0214] .sup.1H NMR (400 MHz, CDCl.sub.3) =5.04-4.89 (m, 1H), 2.62-2.47 (m, 1H), 2.46-2.29 (m, 4H), 2.29-2.19 (m, 2H), 1.84-1.39 (m, 10H), 1.08-1.04 (m, 6H) ppm. .sup.13C NMR (101 MHz, CDCl.sub.3) =209.9, 175.0, 142.7, 131.3, 124.6, 34.6, 34.2, 30.0, 28.5, 26.7, 25.7, 24.3, 18.8, 17.6, 12.2 ppm. GC/MS (EI): m/z (%): 220 (25) [M.sup.+], 205 (2), 191 (12), 163 (4), 138 (100), 123 (22), 109 (29). [0215] Odour description: woody, peppery, green, rooty, stale water, orris.

Example 4-3: 3-methyl-2-(6-methylheptan-2-yl)cyclopent-2-en-1-one

[0216] Following the general procedure described in Example 4-1, [0217] a) 2-(6-methylheptan-2-yl)cyclopentane-1,3-dione was obtained from 2-(6-methylhept-5-en-2-yl)cyclopentane-1,3-dione (10.0 g, 48.0 mmol) as light yellow solid (47.5 mmol, 10.0 g, 99% yield). [0218] b) 3-Methoxy-2-(6-methylheptan-2-yl)cyclopent-2-en-1-one was obtained from 2-(6-methylheptan-2-yl)cyclopentane-1,3-dione (10.0 g, 47.6 mmol) as light yellow liquid (38.4 mmol, 8.6 g, 81% yield). [0219] c) 3-Methyl-2-(6-methylheptan-2-yl)cyclopent-2-en-1-one was obtained from 3-methoxy-2-(6-methylheptan-2-yl)cyclopent-2-en-1-one (1.50 g, 6.7 mmol) and methylmagnesium bromide (4.5 mL, 3.0 M) as colorless liquid (2.0 mmol, 0.42 g, 30% yield). [0220] .sup.1H NMR (400 MHz, CDCl.sub.3) =2.68-2.52 (m, 1H), 2.50-2.42 (m, 2H), 2.38-2.27 (m, 2H), 2.05 (s, 3H), 1.68-1.63 (m, 1H), 1.52-1.43 (m, 2H), 1.25-1.04 (m, 7H), 0.83 (q, J=6.6 Hz, 6H) ppm. .sup.13C NMR (101 MHz, CDCl.sub.3) =209.5, 169.5, 143.7, 38.9, 34.5, 34.5, 31.7, 30.2, 27.8, 25.9, 22.7, 22.5, 18.6, 17.5 ppm. GC/MS (EI): m/z (%): 208 (25) [M.sup.+], 193 (41), 165 (25), 151 (18), 137 (52), 124 (100), 109 (30). [0221] Odour description: woody, green, jasmone, straw, anisic, metallic, rooty.

Example 4-4: 3-ethyl-2-(6-methylheptan-2-yl)cyclopent-2-en-1-one

[0222] Following the general procedure described in Example 4-1, 3-ethyl-2-(6-methylheptan-2-yl)cyclopent-2-en-1-one was obtained from 3-methoxy-2-(6-methylheptan-2-yl)cyclopent-2-en-1-one (3.0 g, 13.4 mmol) and ethylmagnesium bromide (20 mL, 20.1 mmol, 1.0 M) as colorless liquid (2.5 mmol, 0.56 g, 19% yield). [0223] .sup.1H NMR (400 MHz, CDCl.sub.3) =2.59-2.55 (m, 1H), 2.49-2.43 (m, 4H), 2.36-2.27 (m, 2H), 1.72-1.59 (m, 1H), 1.49-1.46 (m, 2H), 1.22-1.04 (m, 10H), 0.83 (dd, J=6.6, 3.0 Hz, 6H) ppm. .sup.13C NMR (101 MHz, CDCl.sub.3) =209.9, 174.7, 143.0, 38.9, 34.6, 34.5, 30.4, 28.5, 27.9, 26.0, 24.3, 22.7, 22.6, 18.8, 12.2 ppm. GC/MS (EI): m/z (%): 222 (33) [M.sup.+], 207 (3), 193 (100), 179 (6), 151 (28), 138 (57), 123 (19), 109 (18). [0224] Odour description: woody, green, oily, stale water.

Example 4-5: 3-methyl-2-(octan-2-yl)cyclopent-2-en-1-one

[0225] Following the general procedure described in Example 4-1, [0226] a) 3-hydroxy-2-(octan-2-yl)cyclopent-2-en-1-one was obtained from cyclopentane-1,3-dione (10.0 g, 101.9 mmol) and octan-2-one (39.2 g, 305.8 mmol) as white solid (63.7 mmol, 13.4 g, 63% yield). [0227] b) 3-methoxy-2-(octan-2-yl)cyclopent-2-en-1-one was obtained from 2-(octan-2-yl)cyclopentane-1,3-dione (10.0 g, 47.6 mmol) as light yellow liquid (38.0 mmol, 8.6 g, 81% yield). [0228] c) 3-methyl-2-(octan-2-yl)cyclopent-2-en-1-one was obtained from 3-methoxy-2-(octan-2-yl)cyclopent-2-en-1-one (3.0 g, 13.4 mmol) and methylmagnesium bromide (6.7 mL, 3.0 M) as colorless liquid (2.7 mmol, 0.56 g, 20% yield). [0229] .sup.1H NMR (400 MHz, CDCl.sub.3) =2.67-2.51 (m, 1H), 2.51-2.41 (m, 2H), 2.36-2.27 (m, 2H), 2.05 (s, 3H), 1.75-1.58 (m, 1H), 1.56-1.39 (m, 1H), 1.36-1.02 (m, 11H), 0.86 (t, J=6.9 Hz, 3H) ppm. .sup.13C NMR (101 MHz, CDCl.sub.3) =209.6, 169.6, 143.7, 34.6, 34.3, 31.8, 31.7, 30.3, 29.3, 28.2, 22.7, 18.6, 17.5, 14.1 ppm. GC/MS (EI): m/z (%): 208 (11) [M.sup.+], 193 (88), 179 (7), 165 (8), 151 (22), 137 (45), 124 (100), 109 (26). [0230] Odour description: green, rooty, fiber, vetiver, woody, spicy, peppery, guayil.

Example 4-6: (E)-3-ethyl-2-(oct-5-en-2-yl)cyclopent-2-en-1-one

[0231] Following the general procedure described in Example 4-1, [0232] a) (E)-3-ethyl-2-(oct-5-en-2-yl)cyclopent-2-en-1-one was obtained from cyclopentane-1,3-dione (27.3 g, 278.1 mmol) and (E)-oct-5-en-2-one (27.0 g, 213.9 mmol) as light yellow solid (10.7 g, 46% yield, purity: 90%). [0233] b) (E)-3-methoxy-2-(oct-5-en-2-yl)cyclopent-2-en-1-one was obtained from (E)-2-(oct-5-en-2-yl)cyclopentane-1,3-dione (10.0 g, 48.0 mmol) as light yellow liquid (29.0 mmol, 6.8 g, 61% yield). [0234] c) (E)-3-ethyl-2-(oct-5-en-2-yl)cyclopent-2-en-1-one was obtained from (E)-3-methoxy-2-(oct-5-en-2-yl)cyclopent-2-en-1-one (6.0 g, 27.0 mmol) and ethylmagnesium bromide (54.0 mL, 1.0 M) as colorless liquid (4.8 mmol, 1.1 g, 18% yield). [0235] .sup.1H NMR (400 MHz, CDCl.sub.3) =5.48-5.22 (m, 2H), 2.72-2.54 (m, 1H), 2.46-2.42 (m, 4H), 2.36-2.24 (m, 2H), 2.09-1.91 (m, 2H), 1.91-1.71 (m, 3H), 1.63-1.46 (m, 1H), 1.20-1.07 (m, 6H), 0.94 (t, J=7.5 Hz, 3H) ppm. .sup.13C NMR (101 MHz, CDCl.sub.3) =209.8, 174.8, 142.7, 132.0, 129.0, 34.6, 34.0, 31.1, 29.9, 28.5, 25.6, 24.6, 18.8, 13.9, 12.2 ppm. GC/MS (EI): m/z (%): 220 (11) [M.sup.+], 205 (1), 191 (29), 150 (33), 138 (100), 123 (23), 109 (31) ppm. [0236] Odour description: woody, green, violet leaf, undecavertol, soft, transparent, iso e super, sylvamber, suede peppery.

Example 4-7: (E)-2-(oct-5-en-2-yl)-3-vinylcyclopent-2-en-1-one

[0237] Following the general procedure described in Example 4-1, (E)-2-(oct-5-en-2-yl)-3-vinylcyclopent-2-en-1-one was obtained from (E)-3-methoxy-2-(oct-5-en-2-yl)cyclopent-2-en-1-one (2.5 g, 11.2 mmol) and vinylmagnesium bromide (45.0 mL, 1.0 M) as colorless liquid (6.1 mmol, 1.4 g, 54% yield). [0238] .sup.1H NMR (400 MHz, CDCl.sub.3) =6.96 (dd, J=10.8, 17.4 Hz, 1H), 5.80-5.22 (m, 4H), 2.83-2.61 (m, 3H), 2.42-2.36 (m, 2H), 2.03-1.52 (m, 6H), 1.18 (d, J=7.1 Hz, 3H), 0.94 (t, J=7.4 Hz, 3H) ppm. .sup.13C NMR (101 MHz, CDCl.sub.3) =209.5, 163.3, 144.4, 132.3, 131.3, 128.7, 120.6, 34.2, 31.0, 29.8, 25.6, 24.8, 18.8, 13.9 ppm. GC/MS (EI): m/z (%): 218 (13) [M.sup.+], 203 (20), 189 (26), 149 (82), 136 (91), 121 (75), 91 (100), 77 (71). [0239] Odour description: peppery, woody, green, metallic, rooty, tagetone, jasmine.

Example 5: 3-methyl-2-(6-methylheptan-2-yl)cyclopentan-1-one

[0240] Following the procedure of example 2-2 (step a), 3-methyl-2-(6-methylhept-5-en-2-yl)cyclopent-2-en-1-one (1.5 g, 7.3 mmol) was fully hydrogenated to get 3-methyl-2-(6-methylheptan-2-yl)cyclopentan-1-one (1.2 g, 78% yield) as colorless liquid. [0241] .sup.13C NMR (101 MHz, CDCl.sub.3, mixture of isomers) =221.7, 220.9, 219.9, 219.5, 61.2, 60.8, 59.0, 58.9, 39.3, 39.2, 39.2, 39.0, 35.7, 35.4, 35.4, 35.0, 34.7, 34.4, 33.3, 33.2, 33.0, 32.6, 32.2, 30.2, 30.1, 29.9, 29.8, 28.0, 27.9, 27.9, 25.6, 25.6, 24.7, 24.3, 22.7, 22.7, 22.6, 21.2, 20.5, 17.9, 17.5, 17.0, 16.8, 15.1, 14.9 ppm. GC/MS (EI): m/z (%): 210 (3) [M.sup.+], 195 (1), 181 (1), 125 (12), 98 (50), 83 (100). [0242] Odour description: peppery, woody, green, fruity.

Example 6: Fragrance Accord

TABLE-US-00001 Ingredient parts by weight DECANAL 0.8 DODECANAL 0.4 OCTANAL 0.3 NONANAL 0.3 ALLYL CAPROATE (2-propenyl hexanoate) 2 BENZYL ACETATE 15 BERGAMOT OIL 120 CEPIONATE (methyl 3-oxo- 60 2-pentylcyclopentaneacetate) CITRONELLOL 30 CITRONELLYL ACETATE 10 (3,7-DIMETHYL-6-OCTEN-1-YL ACETATE) CYCLAL C (2,4-dimethyl-3- 0.2 cyclohexene-1-carbaldehyde) A-DAMASCONE(1-(2,6,6-trimethyl- 2 2-cyclohexen-1-yl)-2-buten-1-one) DIHYDRO MYRCENOL 25 (2,6-dimethyl-7-octen-2-ol) DIPROPYLENE 100 GLYCOL (DPG) HEXENOL-3-CIS 0.3 ISO E SUPER 20 ISORALDEINE 15 LEMON OIL 200 LINALOOL 50 LINALYL ACETATE (3,7-dimethyl- 40 1,6-octadien-3-yl acetate) LINDENOL (2-(4-methyl- 12 3-cyclohexen-1- yl)-2-propanol) LITSEA CUBEBA OIL 3 ORANGE OIL 230 PARADISAMIDE (2-ethyl- 2 n-methyl-n-(3- methylphenyl)butanamide) PETALIA (cyclohexylidene- 3 o-tolyl-acetonitrile) PHENYL ETHYL 20 ALCOHOL (2-phenylethanol) RASPBERRY KETONE 1 (4-(4-hydroxyphenyl)-2-butanone) SYLKOLIDE.sup.1 15 TRIETHYL CITRATE 22.68 VANILLIN 0.02 1000

[0243] 1) (E)-2-(3,5-dimethylhex-3-en-2-yloxy)-2-methylpropyl cyclopropanecarboxylate

[0244] The fragrance accord above is a fresh citrus cologne accord, e.g., suitable to be applied in alcohol at a dosage of 10 wt % to ethanol (85% vol) which is recognizes as a refreshing citrus cologne.

[0245] By replacement of 30 parts DPG with 30 parts of 3-methyl-2-(oct-5-en-2-yl)cyclopent-2-en-1-one results in a accord with more depth and long lastingness. The addition of 3-methyl-2-(oct-5-en-2-yl)cyclopent-2-en-1-one softens the citrus lemon top note and brings a woody ambery cedarwood character with a peppery facet.