GB2529901A - Organic compounds - Google Patents

Abstract

A compound of Formula (I) is disclosed in which R1 and R2 are H or Me and R3 is H, C1-C6 alkyl, C2-C4 alkylidene, or C3-C5 alkenyl. The compound may be selected from 3-(4-isobutyl-2-methylenecyclohexyl)propanal, 2-methyl-3-(2-methylenecyclohexyl)propanal, 3-(4-methyl-2-methylenecyclohexyl)propanal, 2-methyl-3-(4-methyl-2-methylenecyclohexyl)propanal, 3-(4,4-dimethyl-2-methylenecyclohexyl)propanal, 3-(4,4-dimethyl-2-methylenecyclohexyl)-2-methylpropanal, 3-(4-isobutyl-2-methylenecyclohexyl)-2-methylpropanal, 3-(4-isopropyl-2-methylenecyclohexyl)propanal, 3-(4-isopropyl-2-methylenecyclohexyl)-2-methylpropanal, 2-methyl-3-(2-methylene-4-(prop-1-enyl)cyclohexyl)propanal, 3-(4-sec-butyl-2-methylenecyclohexyl)propanal, 3-(4-sec-butyl-2-methylenecyclohexyl)-2-methylpropanal, 3-(4-tert-butyl-2-methylenecyclohexyl)propanal, 3-(4-tert-butyl-2-methylenecyclohexyl)-2-methylpropanal. Use of the compound as a fragrance is further disclosed. A fragrance composition comprising the compound with an odorant and a fragranced article comprising the compound with a consumer product base are also claimed.

Description

Organic Compounds The present invention relates to a novel class of 3-(2'-methylenecyclohexypropanal derivatives possessing odour notes useful for perfumery, which are in the floral, watery range. This invention relates furthermore to flavour and fragrance compositions and flavoured or fragranced articles comprising them.

In the fragrance industry there is a constant demand for new compounds that enhance, modify or improve on odour notes. Surprisingly, it has been found that 3-(2'-methylenecyclohexyl)propanal derivatives of formula (I) as defined below constitute very powerful floral watery odorants.

Surprisingly it was found that the compounds of formula (I) as herein below defined possess unexpected strong floral watery odor characteristics with soft aldehydic, Is creamy and green connotations and being less sharp metallic aldehydic and less fatty fruity than cyclohexane-derivatives without an exo-methylene group in ortho position to the propanal side chain.

To the best of our knowledge none of the compounds as defined herein below has been described as flavor or fragrance ingredient nor is there an indication in the literature that these compounds are suitable as fragrance ingredients.

Accordingly, the present invention refers in one of its aspects to the use as flavor or fragrance of a compound of formula (I) R3 (I) wherein R1 and R2 are independently selected from hydrogen and methyl, and R3 is selected from hydrogen, C1 -C6 alkyl, C2 -C4 alkylidene, and C3 -C5 alkenyl.

Non-limiting examples are compounds of formula (I) wherein R1 and R2 are hydrogen and R3 is selected from methyl, ethyl, and linear or branched C3 -C6 alkyl (e.g. propyl, isopropyl, tert-butyl, 1-methylpropyl, isobutyl, and isopentyl).

Further, non-limiting examples are compounds of formula (I) wherein R1 and R2 are hydrogen and R3 is selected from 02 -04 alkylidene (isopropenyl, isobutenyl, ethenyl, propenyl, and butenyl) and C -05 alkenyl (e.g. 2-methylprop-2-en-1 -yl. prop-2-en-1 -yl, and 3-methyl-but-2-enyl) Further, non-limiting examples are compounds of formula (I) wherein R1 and R2 are independently selected from hydrogen and methyl with the proviso that either is hydrogen and the other is methyl, and R3 is selected from methyl, ethyl, and linear or branched 03-06 alkyl (e.g. propyl, isopropyl, te4rt-butyl, 1 -methylpropyl, isobutyl, and isopentyl).

Further, non-limiting examples are compounds of formula (I) wherein R1 and R2 are independently selected from hydrogen and methyl with the proviso that either is is hydrogen and the other is methyl, and R3 is selected from 02-C4 alkylidene (isopropenyl, isobutenyl, ethenyl, propenyl, and butenyl) and C3 -C5 alkenyl (e.g. 2-methylprop-2-en-1 -yl, prop-2-en-1 -yl, and 3-methyl-but-2-enyl).

Further, non-limiting examples are compounds of formula (I) wherein R1 is hydrogen or methyl, Fl2 is hydrogen and R3 is selected from methyl, ethyl, and linear or branched 03-Ce alkyl (e.g. propyl, isopropyl, tert-butyl, 1 -methylpropyl, isobutyl, and isopentyl).

Further, non-limiting examples are compounds of formula (I) wherein R1 is hydrogen or methyl, Fl2 is hydrogen, and Fl3 is selected from 02-04 alkylidene (isopropenyl, isobutenyl, ethenyl, propenyl, and butenyl) and 0 -C5 alkenyl (e.g. 2-methylprop-2-en- 1 -yl, prop-2-en-1 -yl, and 3-methyl-but-2-enyl).

As a further example one may cite 3-(4'-isobutyl-2'-methylenecyclohexyl)propanal (Ex 1), possessing a strong floral watery, soft aldehydic and creamy odor characteristic. 3- (4'-lsobutyl-2'-methylenecyclohexyl)propanal is more powerful with regard to the odor threshold compared to the corresponding cyclohexane-derivative without the exo- methylene group in ortho position to the propanal side chain. Furthermore 3-(4'-isobutyl-2'-methylenecyclohexyl)propanal is more floral watery, soft aldehydic and creamy and does not have the sharp metallic aldehydic and rubbery facets of the corresponding cyclohexane-derivative without the exo-methylene group.

As further examples one may cite 3-(4'-(tert-buty-2'-methylenecyclohexyl)propanal (Ex 14) and 3-(4'-(tert-butyl)-2'-methylenecyclohexyl)-2-methylpropanal (Ex. 15), possessing floral green aldehydic odor notes, which are slightly less powerful and slightly more aldehydic metallic compared to the compounds of formula (I) wherein R3 is isobutyl, isopropyl or sec-butyl.

Further, non-limiting examples are 2-Methyl-3-(2'-methylenecyclohexypropanal (Ex2), 3-(4'-Methyl-2'-methylenecyclohexypropanal (Ex3), 2-Methyl-3-(4'-methyl-2'-methylenecyclohexyl)propanal (Ex4), 3-(4' ,4'-Dimethyl-2'-methylenecyclohexyl)propanal (Ex5), 3-(4' ,4'-Dimethyl-2'-methylenecyclohexyl)-2-methylpropanal (Ex6), 3-(4'-lsobutyl-2'-methylenecyclohexy-2-methylpropanal (Ex7), 3-(4'-lsopropyl-2'-methylenecyclohexyl)propanal (ExB & Ex9), 3-(4'-lsopropyl-2'-methylenecyclohexyl)-2-methylpropanal (Exi 0), 2-Methyl-3-(2'-methylene-4'-(prop-1 -en-2-yl)cyclohexypropanal (Exi 1), 3-(4'-(sec-Butyl)-2'-methylenecyclohexypropanal ([xl 2), and 3-(4'-(sec-Butyl)-2'-methylenecyclohexy-2-methylpropanal (Exi 3).

The compound of formula (I) may be used alone, as stereoisomeric mixture, or in combination with a base material. As used herein, the base material' includes all 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 admixture 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.

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 colour 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.

As used herein, fragrance composition' means any composition comprising the compound of formula (I) and a base material, e.g. a diluent conventionally used in conjunction with odorants, such as diethyl phthalate (DEP), dipropylene glycol (DPO), lo isopropyl myristate (1PM), triethyl citrate (TEC) and alcohol (e.g. ethanol).

The following list comprises examples of known odorant molecules, which may be combined with the compound of the present invention: -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 ruaridarine oil, myrtle oil, palrnarose oil, patchouli oil, petitgrain oil, jasmine oil, rose oil, sandalwood oil, wormwood oil, lavender oil or ylang-ylang oil; -alcohols, e.g. cinnamic alcohol, c/s-3-hexenol, citronellol, EbanolTM, eugenol, farnesol, geraniol, Super MuguetTM, linalool, menthol, nerol, phenylethyl alcohol, RhodinolTM, SandaloreTM, terpineol or TimberolTM; -aldehydes and ketones, e.g. Azurone® (7-(3-methylbuty-1,5-benzodioxepin-3-one), anisaldehyde, alpha-amylcinnamaldehyde, GeorgywoodTM, hydroxycitronellal, iso E Super®, Isoraldeine®, Hedione®, 3-(4-isobutyl-2-methylphenypropanal, maltol, methyl cedryl ketone, methylionone, verbenone, or vanillin; -ether and acetals, e.g. Ambrox®, geranyl methyl ether, rose oxide, or Spirambrene®; -esters and lactones, e.g. benzyl acetate, cedryl acetate, y-decalactono, Holvotolido®, y-undecalactone or vetivenyl acetate; -macrocycles, e.g. Anibrettolide, ethylene brassylate or Exaltolide®; and -heterocycles, e.g. isobutyichinoline.

The conpound according to 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 0.0001 to 30 weight per cent of the article. In one embodiment, the compound of the present invention may be employed in a fabric 0 softener in an amount from 0.001 to 3 weight per cent. In another embodiment, the compound of the present invention may be used in fine perfumery in amounts from 0.01 to 30 weight per cent (e.g. up to about 10 weight per cent), more preferably between 0.01 and 5 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.

The compound as described hereinabove may be employed in a consumer product base simply by directly mixing the compound of formula (I), or a fragrance composition 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, or it may be chemically bonded to substrates, which are adapted to release the fragrance molecule upon application of an external stimulus such as light, enzyme, oxygen, or the like, and then mixed with the consumer product base.

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

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 the compound of formula (I).

The invention also provides a fragranced article comprising: a) as odorant the compound of formula (I), or a mixture thereof; and b) a consumer product base.

As used herein, consumer product base' means a composition for use as a consumer product to fulfil 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 odours). 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.

Cosmetic products include: (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; (b) cosmetic products with specific effects, especially sunscreens, tanning products, de-pigmenting products, deodorants, antiperspirants, hair removers, and shaving products; (c) cosmetic dental-care products, especially dental and oral care products, tooth care products, cleaners for dental prostheses, adhesives for dental prostheses; and (d) cosmetic hair care products, especially hair shampoos, hair care products, hair setting products, hair-shaping products, and hair colouring products.

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

To the best of our knowledge the compounds of formula (I) as defined herein above have not been described in literature before. Thus there is provided in a further aspect of the invention a compound of formula (I) R3 _jJ'i' R2 (I) wherein R1 and R2 are independently selected from hydrogen and methyl R3 is selected from hydrogen, C1 -C6 alkyl (e.g. methyl, ethyl, and linear or branched C3 -C6 alkyl, such as propyl, isopropyl, tert-butyl, 1 -methylpropyl, isobutyl, and isopentyl), 02-04 alkylidene (isopropenyl, isobutenyl, ethenyl, propenyl, and butenyl), and C3-C5 alkenyl (e.g. 2-methylprop-2-en-1-yl, prop-2-en-1-yl, and 3-methyl-but-2-is enyl).

The compounds of formula (I) give rise to a number of stercoisomers, and can be resolved into individual enriched or pure enantiomers or diastereomers. As one particular example one may cite (1 4)-trans and (1 4)-c/s derivatives, of which the trans-derivatives are more powerful and possess a more floral watery odor characteristic. Resolving stereoisomers however adds to the complexity of manufacture and purification of these compounds, as does a stereoselective synthetic approach, and thus 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. by preparative HPLC and GC or by stereoselective synthesis.

It may also be noted that the compounds of formula (I) as hereinabove defined may undergo an enzyme-mediated degradation, but the formation of benzoic acid derivatives was not observed.

S

The compounds of formula (I) may be prepared in 3-4 steps as depicted in Scheme 1 below, starting from the corresponding cyclohexanones 2. The latter may be converted into enamines which can be directly alkylated with ethyl acrylate, ethyl methacrylate or acrylonitrile to yield the corresponding ketoesters 3 or ketonitriles 6. A Wittig reaction of the keto-groups of compounds 3 and 6 respectively with methylene-triphenyl- phosphorane gives substituted ethyl-(2'-methylenecyclohexy-propanoates 4 or (2'-methylenecyclohexyl)propanenitriles 7. Whereas the nitriles 7 may directly be converted into the desired aldehydes of formula (I), the esters 4 may be reduced to the alcohols 5 and re-oxidized to yield aldehydes of formula (I) or may also be directly converted to lo aldehydes of formula (I) by methods known in the art.

Scheme 1: a) b) 3.) c) _JJ'T'' d) Os e) b) a) i: pyrrolidine, toluene, H: ethyl acrylate or ethyl methacrylate, EtOH; b) KOtBu, MePPh3Br, THF; c) LiAIH4, Et,O; d) PCCICelite, CH2CI2; e) i: pyrrolidine, toluene, H: acrylonitrile; f) DIBAL-H, CH2CI2; R1, R2 and P3 have the same meaning as given for formula (I) 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.

All products described in the examples were obtained starting from cyclohexanones 2, which are either commercially available (e.g. cyclohexanone, 3-methylcyclohexanone, 3,3-dimethylcyclohexanone) or may be prepared by methods known in the art from 2- cyclohexen-1-one, a Grignard reagent and Cul (e.g. 3-isopropylcyclohexanone, 3-isobutylcyclohexanone, 3-(sec-butyl)cyclohexanone, 3-(prop-1 -en-2-yl)cyclohexanone) or via hydrogenation of the corresponding phenol (e.g. 3-(tert-butyl)cyclohexanone).

The products were purified after work-up by either flash chromatography (EC) using Merck silica gel 60 (particle size 0.040-0.063 mm) or distillation. NMR spectra were measured in ODd3 or C6D6 and are reported relative to TMS as follows: chemical shifts (3 ppm), coupling constants J in Hz. CC-MS analyses were run on a MSD5975C mass spectrometer and are reported as rnlz list (relative intensity).

Example 1: 3-(4'-lsobutyl-2'-methylenecyclohexyl)propanal a) Pyrrolidine (1.0 mL, 12.4 mmol) was added to 3-isobutylcyclohexanone (1.74 g, 11.3 mmol) in toluene (12 mL). The flask was fitted with a Dean-Stark trap, and the mixture was refluxed at 120 °C for 1 h. The volatiles were removed, the crude enamine was re-dissolved in EtOH (3 mL) and ethyl acrylate (1.8 mL, 16.6 mmol) was added at C. The mixture was stirred at 60 °C for 16 h and at reflux for 1 h after addition of H20 (1.i mL) and AcOH (0.55 mL). The aqueous layer was extracted with MTBE and the organic phases were washed with 2M aq. HCI, dried (MgSO4), and filtered. The filtrate was concentrated and the residue was purified by distillation in the "Kugelrohr" oven (160 C, 0.06 torr) to yield 0.86 g (30%) of ethyl 3-(4'-isobutyl-2'-oxocyclohexyl)-propanoato as a colorless oil.

Potassium t-butylat (3.87 mL, 1 M in THF) was added to a solution of methyltriphenyl-phosphonium bromide (1.32 g, 3.70 mmol) in THE (8 mL) at 0°C. After the yellow suspension was stirred at 25 C for 30 mm, ethyl 3 -(4'-isobutyl-2-oxocyclohexyl)-propanoate (0.86 g, 3.38 mmol) in THF (8 mL) was added, and the mixture was stirred at 70 C for 2 h. After addition of H 20 at 25 t, the aqueous layer was extracted with hexane (2x). The organic phases were washed with MeOH/H20 (4:1; 2x), dried (MgSO4, filtered and the filtrate was concentrated. The residue was purified by distillation in the "Kugelrohr" oven (150, 0.06 torr) to yield 0.48 g (57%) of ethyl 3-(4'-isobutyl-2'-methylenecyclohexyl)propanoate as a colorless oil.

Ethyl 3-(4'-isobutyl-2'-methylenecyclohexyl)propanoate (0.48 g, 1.92 mmol) in Et20 (4 mL) was added to a suspension of LiAIH4 (0.07 g, 1.92 rnrnol) in Et20 (4 mL) at 0 t and the mixture was stirred at 25 °C for 1 h. The reaction was quenched with H20 (0.1 mL), 3M aq NaOH (0.1 mL) and H20 (0.2 mL), and stirred vigorously for 10 mm.

MgSO4 was added and the mixture was stirred for an additional 30 mm. The white solid was removed by filtration and the filtrate was concentrated to afford 0.34 g (85%) of 3- (4'-isobutyl-2'-methylenecyclohexypropan-1 -ol as a colorless oil.

b) A solution of 3-(4'-isobutyl-2'-methylenecyclohexypropan-1 -ol from Example 1 a (0.34 g, 1.62 mmol) in CH2CI2 (4 mL) was added to a suspension of PCC (0.35 g, 1.62 mmol) and Celite (0.35 g) in CH2CI2 (4 mL). The mixture was stirred at 25 °C for 2 h, filtered through a pad of Si02 and washed with CH2CI2. The filtrate was concentrated and the residue was purified by FC on Si02 (hexane/EtOAc 98:2) to yield 0.21 g (62%) of thetitle compound as a colorless oil.

1H NMR (CDCI3, 400 MHz): 6 = 9.79 (t, 1= 1.7 Hz, 1H), 4.73-4.68 (m, 1H), 4.57-4.51 (m, 1H), 2.52-2.48 (m, 2H), 2.32 (ddd, J= 12.5, 3.7, 1.7 Hz, 1H), 2.03-1.92 (m, 1H), 1.91-1.75(m, 3H), 1.70-1.54(m, 3H), 1.52-1.42(m, 1H), 1.13-0.96(m, 4H), 0.86(d, J= 6.6 Hz, 3H), 0.85 (d, J= 6.6 Hz, 3H) ppm.

13C-NMR (CDCI3, 100 MHz): 6 = 202.7 (d), 151.6 (s), 105.1 (t), 46.0 (t), 43.2 (t), 42.3 (d), 42.0 (t), 37.4 (d), 33.4 (t), 32.5 (t), 24.8 (d), 24.2 (t), 22.9 (q), 22.8 (q) ppm.

MS (El): 208 (M, 8), 190 (21), 175 (7), 164 (15), 147 (49), 133 (100), 121 (30), 107 (66), 95(50), 91(56), 79(40), 67(29), 55(27), 41(39), 29(14).

Odour description: floral watery, soft aldehydic, creamy.

Example 2: 2-Methyl-3-(2'-methylenecyclohexyl)propanal According to Example la, the enamine of cyclohexanone was alkylated with ethyl methacrylate to give ethyl 2-methyl-3-(2'-oxocyclohexyl)propanoate (70%, yellow oil), which was further converted into ethyl 2-methyl-3-(2'-methylenecyclohexyl)propanoate (80%, colorless oil) which was reduced to 2-methyl-3-(2'-methylenecyclohexyl)propan- 1-ol (99%, colorless oil).

According to Example 1 b, starting from 2-methyl-3-(2'-methylenecyclohexypropan-1 -ol (13.5g. 80.0 mmol), 6.45 g (48%) of the title compound was obtained as a mixture of two diastereomers (ratio 3:2) after purification by FC on Si02 (hexane/EtOAc 99:1 98:2) as a light yellow oil.

1H NMR (G6D6, 400 MHz); mixture of isomers: 6 = 9.32 (d, J= 1.8 Hz, 1H), 9.31 (d, J= 1.5 Hz, 1H), 4.71 -4.68 (m, 2H), 4.57-4.55 (m, 2H), 2.10-1.86 (m, 8H), 1.60-1.04 (m, 15H), 0.92-0.85(m, 1H), 0.80(d, J= 6.8 Hz, 3H), 0.77(d, J= 7.1 Hz, 3H) ppm.

13C-NMR (C6D6, 100 MHz); mixture of isomers: 6 = 203.7 (d), 203.6 (d), 152.3 (s), 151.9 (s), 107.6 (t), 107.1 (t), 44.6 (d), 44.4 (d), 41.1 (d), 41.0 (d), 35.1 (t), 34.5 (t), 34.4 (t), 34.1 (t), 33.5 (t), 33.3 (t), 29.4 (t), 29.3 (t), 24.4 (t), 24.0 (t), 14.2 (q), 14.0 (q) ppm.

MS (El); sum of isomers: 166 (Mt, 7), 151 (8), 148 (17), 133 (36). 124 (18). 119 (14), 108 (80), 93(100), 81(86), 67(82), 55(45), 41(75), 29(70).

Odour description: creamy floral, soft aldehydic, fresh woody.

Example 3: 3-(4'-Methyl-2'-methylenecyclohexyflpropanal According to Example la, the enamine of 3-methylcyclohexanone was alkylated with ethyl acrylate to give ethyl 3-(4'-methyl-2'-oxocyclohexypropanoate (15%, yellow oil), which was further converted into ethyl 3-(4'-methyl-2'-methylenecyclohexyl)propanoate (60%, colorless oil) which was reduced to 3-(4'-methyl-2'-methylenecyclohexyl)propan- 1-ol (99%, colorless oil).

According to Example 1 b, starting from 3-(4'-methyl-2'-methylenecyclohexypropan-1 -ol (1.36 g, 8.07 mmol), 0.96 g (72%) of the title compound was obtained after purification by EC on SiO2 (cyclohexane/EtOAc 99:1 -* 98:2 -, 95:5) as a colorless oil.

1H NMR (CDCI3, 400 MHz): 6 = 9.80 (t, J= 1.7 Hz, 1H), 4.73-4.70 (m, 1H), 4.57-4.55 (m, 1H), 2.55-2.47 (m, 2H), 2.31 (ddd, J = 12.6, 3.8, 2.0 Hz, 1H), 2.02-1.94 (m, 1H), 1.90-1.80 (m, 2H), 1.79-1.74 (m, 1H), 1.68-1.58 (m, 2H), 1.57-1.46 (m, 1H), 1.16-0.98 (m, 2H), 0.92 (d, J= 6.5 Hz, 3H) ppm.

3C-NMR (CDCI3, 100 MHz): 6 = 202.7 (d), 151.6 (s), 105.1 (t), 44.9 (t), 42.0 (t), 41.9 (d), 34.9 (d), 34.4 (t), 33.4 (t), 24.2 (t), 21.9 (q) ppm.

MS (El): 166 (M', 8), 151 (11), 148 (50), 133 (74), 122(45), 107 (100), 93 (67), 79(56), 67 (58), 55 (38), 41(56), 29 (36).

Odour description: creamy, floral green

Example 4: 2-Methyl-3-(4'-methyl-2'-methylenecyclohexyl)propanal According to Example 1 a, the enamine of 3-methylcyclohexanone was alkylated with ethyl methacrylate to give ethyl 2-methyl-3-(4'-methyl-2'-oxocyclohexypropanoate (98%, orange oil), which was further converted into ethyl 2-methyl-3-(4'-methyl-2'- methylenecyclohexyl)propanoate (78%, colorless oil) which was reduced to 2-methyl-3- (4'-methyl-2'-methylenecyclohexyl)propan-1 -ol (99%, colorless oil).

According to Example 1 b, starting from 2-methyl-3-(4'-methyl-2'-methylenecyclohexyl)-propan-1-ol (5.33 g, 29.2 mmol), 2.19 g (42%) of the title compound was obtained as a mixture of two diastereomers (ratio 3:2) after purification by FC on SiO2 (cyclohexane/EtOAc 98:2 -95:5) as a colorless oil.

H NMR (CDCI3, 400 MHz); mixture of isomers: = 9.67-9.57 (m, 2H), 4.74-4.69 (m, 2H), 4.58-4.55 (m, 2H), 2.49 (dqd, J= 13.9, 7.1, 2.0 Hz, 2H), 2.35-2.27 (m, 2H), 2.15- 2.07 (m, 1H), 1.98-1.90 (m, 2H), 1.90-1.82 (m, 2H), 1.81-1.74 (m, 2H), 1.74-1.62 (m, 3H), 1.60-1.48 (m, 3H), 1.28-1.20(m, 1H), 1.17-0.95(m, 1OH), 0.93 (d, J= 6.3 Hz, 3H), 0.92 (d, J= 6.6 Hz, 3H) ppm.

3C-NMR (ODd3, 100 MHz); mixture of isomers: ö = 205.3 (d), 205.2 (d), 152.0 (s), 151.6 (s), 105.3 (t), 105.0 (t), 45.1 (t), 44.8 (t), 44.0 (d), 43.9 (d), 39.7 (d), 39.6 (d), 35.0 (d), 34.9 (ci), 34.4 (t), 34.2 (t), 33.7 (t), 33.3 (t), 33.2 (t), 32.8 (t), 22.0 (q), 21.8 (q), 14.2 (q), 13.7 (q) ppm.

MS (El); sum of isomers: 180 (M'S, 8), 165 (9), 162 (28), 147 (52), 137 (14), 122 (40), 107 (91), 95(100), 81(71), 67(61), 55(44), 41(70), 29(42).

Odour description: green citrus fatty, floral, woody creamy, cedarwood fig. Example 5: 3-(4',4'-Dimethyl-2'-methylenecyclohexyl)propanal According to Example la, the enamine of 3,3-dimethylcyclohexanone was alkylated with ethyl acrylate to give after distillation ethyl 3-(4',4'-dimethyl-2'-oxocyclohexyl)- propanoate (46%. colorless oil), which was further converted into ethyl 3-(4'.4'-dimethyl- 2'-methylenecyclohexyl)-propanoate (60%, colorless oil) which was reduced to 3-(4',4'-dimethyl-2'-methylenecyclohexyl)-propan-l -ol (93%, colorless oil).

According to Example 1 b, starting from 3-(4',4'-dimethyl-2'-niethylenecyclohexyl)-propan-1-ol (3.11 g, 17.1 mmol), 1.85 g (60%) of the title compound was obtained after purification by FC on Si02 (hexane/EtOAc 98:2 -. 95:5) as a colorless oil. I 0

1H NMR (CDCI3, 400 MHz): 6 = 9.78 (t, J= 1.6 Hz, 1H), 4.66-4.62 (m, 2H), 2.48-2.40 (m, 2H), 2.03-1.87 (m, 3H), 1.84-1.78 (m, 1 H), 1.76-1.65 (m, 1 H), 1.65-1.55 (m, 1 H), 1.49-1.40 (m, 1H), 1.33-1.23 (m, 2H), 0.88 (s, 3H), 0.85 (s, 3H) ppm.

13C-NMR (CDCI3, 100 MHz): 6 = 202.6 (d), 149.1 (s), 108.1 (t), 47.4 (t), 42.1 (t), 41.9 (d), 36.7 (t), 32.8 (s), 29.2 (t), 28.4 (q), 28.1 (q), 23.9 (t) ppm.

MS (El): 180 (M, 14), 165 (20), 162 (26), 147 (86), 136 (52), 121 (76), 109 (57), 93 (100), 81(52), 69(62), 55(41), 41(78), 29(42).

Odour description: green resinous, watery floral, soft aldehydic.

Example 6: 3-(4',4'-Dimethyl-2'-methylenecyclohexyl)-2-methylpropanal According to Example la, the enamine of 3,3-dimethylcyclohexanone was alkylated with ethyl methacrylate to give after distillation ethyl 3-(4',4'-dimethyl-2'-oxocyclohexyl)- 2-methylpropanoate (91%, colorless oil), which was further converted into ethyl 3-(4',4'-dimethyl-2'-methylenecyclohexyl)-2-methylpropanoate (71%, colorless oil) which was reduced to 3-(4' ,4'-dimethyl-2'-methylenecyclohexy-2-methylpropan-1 -ol (85%, colorless oil).

According to Example 1 b, starting from 3-(4',4'-dimethyl-2'-methylenecyclohexyl)-2-methylpropan-1-ol (5.77g. 29.4 mmol), 3.21 g (56%) of the title compound was obtained as a mixture of two diastereomers (ratio 1:1) after purification by flash chromatography on SiO2 (hexane/EtOAc 99:1 -98:2 -95:5) as a light yellow oil.

1H NMR (ODd3, 400 MHz); mixture of isomers: 6 = 9.65 (d, J = 2.0 Hz, 1 H), 9.63 (d, J= 2.2 Hz, 1H), 4.70-4.66 (m, 4H), 2.48-2.37 (m, 2H), 2.18-2.12 (m, 2H), 2.01-1.98 (m, 2H), 1.87-1.81 (m, 2H), 1.80-1.71 (m, 3H), 1.64-1.56 (m, 1 H), 1.50-1.42 (m, 2H), 1.34- 1.26 (m, 4H), 1.22-1.18 (m, 1 H), 1.10 (d, J= 7.1 Hz, 3H), 1.09 (d, J = 7.1 Hz, 3H), 0.99- 0.97 (m, 1 H), 0.89 (s, 3H), 0.88 (s, 3H), 0.88 (s, 3H), 0.86 (s, 3H) ppm.

13G-NMR (ODd3, 100 MHz); mixture of isomers: 3 = 205.2 (d), 205.2 (d), 149.5 (s), 149.1 (s), 108.5 (t), 108.0 (t), 47.9 (t), 47.1 (t), 44.2 (d), 44.0 (d), 39.8 (d), 39.7 (d), 36.9 (t), 36.4 (t), 32.9 (2s), 32.8 (1), 32.6 (t), 29.5 (t), 29.1 (t), 28.8 (q), 28.5 (q), 28.0 (q), 27.7 (q), 13.9 (q), 13.6 (q) ppm.

MS (El); sum of isomers: 194 (M, 15), 179(19), 176(17), 161 (71), 152(11), 136 (41), 121 (78), 109 (68), 105 (51), 93(100), 81(62), 69(50), 55(41), 41(80), 29(36).

Odour description: sweet green, slightly fatty, leathery.

Example 7: 3-(4'-lsobutyl-2'-methylenecyclohexyD-2-methylpropanal According to Example 1 a, the enamine of 3-isobutylcyclohexanone was alkylated with ethyl methacrylate to give after distillation ethyl 3-(4'-isobutyl-2'-oxocyclohexyl)-2- methylpropanoate (74%, colorless oil), which was further converted into ethyl 3-(4'-isobutyl-2'-methylenecyclohexyl)-2-methylpropanoate (84%. colorless oil) which was reduced to 3-(4'-isobutyl-2'-methylenecyclohexyl)-2-methylpropan-1 -ol (87%, colorless oil).

According to Example 1 b, starting from 3-(4'-isobutyl-2'-methylenecyclohexyl)-2-methylpropan-1 -ol (1.35g. 6.02 mmol), 0.77 g (58%) of the title compound was obtained as a mixture of two diastereomers (ratio 3:2) after purification by FC on Si02 (hexane/EtOAc 98:2 -95:5) as a colorless oil.

1H NMR (CDCI3, 400 MHz); mixture of isomers: 3 = 9.64 (d, J = 2.0 Hz, 1 H), 9.60 (d, J= 2.1 Hz, 1H), 4.74-4.70 (m, 2H), 4.59-4.52 (m, 2H), 2.55-2.44 (m, 2H), 2.37-2.28 (m, 2H), 2.11 (dt, J= 13.9, 7.0 Hz, 1 H), 2.01-1.90 (m, 2H), 1.90-1.83 (m, 2H), 1.82-1.77 (m, 2H), 1.76-1.53(m, 7H), 1.52-1.42(m, 2H), 1.24(dt, J= 13.9, 6.9 Hz, 1H), 1.12-0.98(m, 13H), 0.86 (dd, J= 6.6, 1.0 Hz, 6H), 0.85 (dd, J = 6.6, 1.0 Hz, 6H) ppm.

13C-NMR (CDCI3, 100 MHz); mixture of isomers: 3 = 205.2 (d), 205.2 (d), 152.0 (s), 151.7 (s), 105.3 (t), 104.9 (t), 46.1 (t), 45.9 (t), 44.0 (d), 43.9 (d), 43.4 (t), 43.1 (t), 40.1 (d), 40.0 (d), 37.5 (d), 37.4 (d), 33.7 (1), 33.4 (t), 33.3 (1), 32.9 (t), 32.6 (t), 32.3 (t), 24.8 (2d), 22.9 (2q), 22.8 (2q), 14.2 (q), 13.7 (q) ppm.

MS (El); sum of isomers: 222 (M', 6), 204 (14), 189 (8), 161 (25), 147 (58), 124 (34), 107 (80), 95 (100), 79(56), 67(42), 55(41), 41(83), 29(33).

Odour description: floral watery, metallic marine, coriander leaf.

Example 8: 3-(4'-lsopropyl-2'-methylenecyclohexyl)propanal According to Example la, the enamine of 3-isopropylcyclohexanone was alkylated with ethyl acrylate to give after distillation 3-(4'-isopropyl-2'-oxocyclohexyl)-propanoate (35%, colorless oil), which was further converted into ethyl 3-(4'-isopropyl-2'- methylenecyclohexyl)propanoate (75%, colorless oil) which was reduced to 3-(4'-isopropyl-2'-methylenecyclohexypropan-1 -ol (90%, colorless oil).

According to Example 1 b, starting from 3-(4'-isopropyl-2'-methylenecyclohexyl)propan- 1-ol (1.68g, 8.56 mmol), 0.19g (11%) of the rac-(1',4')-trans-isomer of the title compound was obtained after purification by FC on Si02 (hexane/EtOAc 98:2) as a colorless oil.

Data for rac-(1,4')-trans-3-(4'-lsopropyl-2'-methylenecyclohexyl)propanal: 1H NMR (CDCI3, 400 MHz): S = 9.80 (t, J= 1.7 Hz, 1H), 4.73-4.71 (m, 1H), 4.56-4.55 (m, 1 H), 2.54-2.49 (m, 2H), 2.34-2.30 (m, 1 H), 2.02-1.94 (m, 1 H), 1.92-1.69 (m, 4H), 1.65-1.56(m, 1H), 1.51-1.43(m, 1H), 1.23-1.12(m, 2H), 1.04-0.94(m, 1H), 0.88(d, J= 6.8 Hz, 3H), 0.87 (d, J= 6.6 Hz, 3H) ppm.

13C-NMR (ODd3, 100 MHz): S = 202.7 (d), 152.1 (s), 104.8 (t), 46.4 (d), 42.2 (d), 42.0 (t), 40.2 (t), 33.8 (t), 32.4 (d), 29.3 (t), 24.3 (t), 19.8 (q), 19.7 (q) ppm.

MS (El): 194 (Mt, 5), 176 (12), 161 (8), 151 (19), 133 (100), 123 (8), 107 (80), 95(29), 91(52), 82(27), 79(35), 67(23), 55(21), 41(36), 29(14).

Odour description: floral green, soft aldehydic, creamy, slightly anisic.

Example 9: 3-(4'-lsopropyl-2'-methylenecyclohexyl)propanal According to Example la, the enamine of 3-isopropylcyclohexanone was alkylated with ethyl acrylate (in contrast to Example 8 at 25 t and not at 60 t) to give after distillation 3-(4'-isopropyl-2'-oxocyclohexy-propanoate (53%, colorless oil), which was further converted into ethyl 3-(4'-isopropyl-2'-methylenecyclohexyl)propanoate (65%, colorless oil) which was reduced to 3-(4'-isopropyl-2'-methylenecyclohexypropan-1 -ol (98%, colorless oil).

According to Example 1 b, starting from 3-(4'-isopropyl-2'-methylenecyclohexyl)propan- 1-al (2.36 p, 12.0 mmol), 1.45 g (62%) of a mixture of the rac-(1'.4')-trans-and rac- (1,4)-c/s-isomer (ratio 10:1) of the title compound was obtained after purification by FC on Si02(hexane/EtOAc 199:1 -i 99:1) as a colorless oil.

Spectral data of rac-(1,4')-trans-3-(4'-isopropyl-2'-methylenecyclohexyl)propanal are reported in Example 8. I 0

Data for rac-(1,4')-cis-3-(4'-isopropyl-2'-methylenecyclohexypropanal: 1H NMR (C6D6, 600 MHz): ö = 9.37 (t, J= 1.3 Hz, 1 H), 4.70-4.69 (m, 1H), 4.60-4.59 (m, 1 H), 2.03 (dd, J= 13.4, 3.2 Hz, 1 H), 2.01-1.97 (m, 1 H), 1.92-1.81 (m, 2H), 1.71-1.60 (m, 2H), 1.47-1.44 (m, 2H), 1.37-1.27 (m, 3H), 1.13-1.04 (m, 2H), 0.82 (d, J= 6.8 Hz, 3H), 0.82 (d, J= 6.6 Hz, 3H) ppm.

13C-NMR (C6D6, 150 MHz): ö = 200.3 (d), 150.7 (s), 108.8 (t), 46.2 (d), 42.7 (d), 42.3 (1), 35.0 (t), 32.7(d), 32.3(t), 24.4 (t), 24.1 (t), 19.9(q), 19.9 (q) ppm.

MS (El): 194 (Mt, 5), 176(11), 161 (7), 151 (20), 133 (95), 107 (100), 95(45), 91(71), 82(45), 81(38), 79(52), 67(44), 55(62), 41(67), 29(14).

Odour description: floral, fruity aldehydic, citrus.

Example 10: 3-(4'-lsopropyl-2'-methylenecyclohexyl)-2-methylpropanal According to Example la, the enamine of 3-isopropylcyclohexanone was alkylated with ethyl methacrylate to give ethyl 3-(4'-isopropyl-2'-oxocyclohexy-2-methylpropanoate (94%, orange oil), which was further converted into ethyl 3-(4'-isopropyl-2'- methylenecyclohexyl)-2-methylpropanoate (81%, colorless oil) which was reduced to 3- (4'-isopropyl-2'-methylenecyclohexyl)-2-methylpropan-1 -ol (90%, colorless oil).

According to Example lb, starting from 3-(4'-isopropyl-2'-methylenecyclohexy-2-methylpropan-1-ol (6.10 g, 29.0 mmol), 3.32 g (55%) of the title compound was obtained as a mixture of two diastereomers (ratio 3:2) after purification by FC on SiO2 (cyclohexane/EtOAc 99:1 -÷ 98:2) as a light yellow oil.

1H NMR (CDCI3, 400 MHz); mixture of isomers: ö = 9.64 (d, J = 2.0 Hz, 1 H), 9.61 (d, J= 2.2 Hz, 1H), 4.74-4.70(m, 2H), 4.58-4.53(m, 2H), 2.51 (dqd, 1= 14.3, 7.1, 2.1 Hz, 2H), 2.38-2.29 (m, 2H), 2.11 (ddd, J= 13.9, 7.4, 6.4 Hz, 1H), 1.97-1.86 (m, 4H), 1.83-1.66 (m, 5H), 1.63-1.53 (m, 1H), 1.53-1.41 (m, 2H), 1.29-1.21 (m, 1H), 1.21-1.14 (m, 4H), 1.13(d, J= 7.1 Hz, 3H), 1.11 (d, J= 7.3 Hz, 3H), 1.01-0.91 (m, 2H), 0.89(dd, J= 6.9, 1.7 Hz, 6H), 0.88(dd, J= 6.9, 2.0 Hz, 6H) ppm.

3C-NMR (CDCI3, 100 MHz); mixture of isomers: ö = 205.3 (d), 205.2 (d), 152.5 (s), 152.3 (s), 104.9 (t), 104.7 (t), 46.5 (2d), 44.0 (d), 43.9 (d), 40.4 (t), 40.2 (t), 40.1 (d), 40.0 (d), 34.2 (t), 33.7 (t), 33.4 (t), 32.9 (t), 32.5 (d), 32.3 (d), 29.4 (t), 29.3 (t), 19.8 (q), 19.8 (q), 19.8 (q), 19.7 (q), 14.3 (q), 13.7 (q) ppm.

MS (El); sum of isomers: 208 (Ml 5), 190 (11), 175 (8), 165 (12), 147 (70), 135 (7), 124 (22), 107 (100), 95(67), 82(39), 67(25), 55(25), 41(48), 29(16).

Odour description: floral green, fruity.

Example 11: 2-Methyl-3-(2'-methylene-4'-(prop-1 -en-2-yl)cyclohexyl)propanal According to Example 1 a, the enamine of 3-(prop-1 -en-2-yl)cyclohexanone was alkylated with ethyl methacrylate to give ethyl 2-methyl-3-(2'-oxo-4'-(prop-1-en-2- yl)cyclohexypropanoate (80%, orange oil), which was further converted into ethyl 2-methyl-3-(2'-methylene-4'-(prop-1 -en-2-ycyclohexyl)propanoate (76%, colorless oil) which was reduced to 2-methyl-3-(2'-methylene-4'-(prop-1 -en-2-yl)cyclohexyl)-propan- 1-ol (99%, colorless oil).

According to Example 1 b, starting from 2-methyl-3-(2'-methylene-4'-(prop-1 -en-2-yl)cyclohexy-propan-1-ol (3.74 g, 18.0 mmol), 0.94 g (26%) of the title compound was obtained as a mixture of two diastereomers (ratio 3:2) after purification by FC on SiO2 (cyclohexane/EtOAc 99:1 -÷ 98:2) as a light yellow oil.

1H NMR (CDCI3, 400 MHz); mixture of isomers: ö = 9.65 (d, J = 2.0 Hz, 1 H), 9.61 (d, J= 2.4 Hz, 1H), 4.79-4.71 (m, 6H), 4.61-4.58 (m, 2H), 2.60-2.44 (m, 2H), 2.43-2.34 (m, 2H), 2.12 (ddd, J= 13.9, 7.6, 6.4 Hz, 1H), 2.07-1.90 (m, 8H), 1.89-1.81 (m, 2H), 1.78- 1.66 (m, 7H), 1.64-1.54(m, 1H), 1.44-1.35(m, 2H), 1.31-1.22(m, 1H), 1.14 (d, J= 7.1 Hz, 3H), 1.12(d, J= 7.1 Hz, 3H), 1.12-0.93 (m, 2H) ppm.

13C-NMR (CDCI3, 100 MHz); mixture of isomers: 3 = 205.1 (d), 205.1 (d), 151.8 (s), 151.6 (s), 149.6 (s), 149.5 (s), 108.7 (t), 108.6 (t), 105.4 (t), 105.3 (t), 47.6 (2d), 43.9 (d), 43.8 (d), 42.2 (t), 42.1 (t), 39.8 (d), 39.7 (d), 34.2 (1), 33.7 (t), 33.3 (t), 32.8 (t), 31.5 (t), 31.5(t), 20.8 (2q), 14.4 (q), 13.7(q) ppm.

MS (El); sum of isomers: 206 (Mt, 1), 188 (20), 173 (19), 159 (9), 145 (49), 133 (36), 121 (23), 105 (100), 93(71), 79(44), 67(25), 55(22), 41(42), 29(19).

Odour description: green, soft aldehydic, coriander, vegetable.

Example 12: 3-(4'-(sec-Butylj-2'-methylenecyclohexyl)propanal According to Example 1 a, the enamine of 3-(sec-butycyclohexanone was alkylated with ethyl acrylate to give after distillation ethyl 3-(4'-(sec-butyl)-2'-oxocyclohexyl)- propanoate (11%, yellow oil), which was further converted into ethyl 3-(4'-(sec-butyl)-2'- methylenecyclohexyl)propanoate (79%, light yellow oil) which was reduced to 3-(4'- (sec-butyl)-2'-methylenecyclohexyl)propan-l -ol (92%, colorless oil).

According to Example ib, starting from 3-(4'-(sec-butyl)-2'-methylenecyclohexyl)-propan-1 -ol (1.14 g, 5.43 mmol), 0.72 g (63%) of the title compound was obtained as a mixture of two diastereomers after purification by EC on SiC2 (cyclohexane/EtOAc 99:1 -÷ 98:2) as a colorless oil.

1H NMR (CDCI3, 400 MHz); mixture of isomers: 3 = 9.80 (t, J= 1.6 Hz, 2H), 4.72 (d, J= 1.1 Hz, 2H), 4.55 (br. s, 2H), 2.56-2.47 (m, 4H), 2.30-2.22 (m, 2H), 2.02-1.93 (m, 2H), 1.92-1.86 (m, 2H), 1.85-1.68 (m, 6H), 1.65-1.56 (m, 2H), 1.47-1.08 (m, 1OH), 1.06-0.92 (m, 2H), 0.87 (t, J= 7.1 Hz, 6H), 0.84 (d, J= 6.6 Hz, 3H), 0.84 (d, J= 6.9 Hz, 3H) ppm.

13C-NMR (CDCI3, 100 MHz); mixture of isomers: 3 = 202.7 (d), 202.7 (d), 152.4 (s), 152.3 (s) 104.8 (t), 104.7 (1), 44.6 (2d), 42.3 (2d), 42.0 (2t), 41.0(t), 39.2 (t), 39.0 (2d), 34.0 (t), 33.9 (t), 30.1 (t), 28.2 (t), 26.7 (t), 26.6 (t), 24.3 (t), 24.3 (t), 15.6 (q), 15.6 (q) 11.8(2q), ppm.

MS (El); sum of isomers: 208 (M, 4), 190 (10), 175 (2), 164 (6), 161 (15), 151 (17), 133 (100), 123 (37), 107 (60), 91(47), 79(27), 67(17), 55(22), 41(28), 29(20).

Odour description: floral green, sapy privet, glycolierral.

Example 13: 3-(4'-(sec-Butyfl-2'-methylenecyclohexyfl-2-methylpropanal According to Example 1 a, the enamine of 3-(sec-butyl)cyclohexanone was alkylated with ethyl methacrylate to give ethyl 3-(4'-(sec-butyl)-2'-oxocyclohexy-2- methylpropanoate (84%. orange oil), which was further converted into ethyl 3-(4'-(sec-butyl)-2'-methylenecyclohexyl)-2-methylpropanoate (75%, colorless oil) which was reduced to 3-(4'-(sec-butyl)-2'-methylenecyclohexyl)-2-methylpropan-1 -ol (93%, colorless oil). According to Example ib, starting from 3-(4'-(sec-butyl)-2'-methylenecyclohexyl)-2-methylpropan--ol (6.70 g, 29.9 mmol). 3.78 g (57%) of the title compound was obtained as a mixture of four diastereomers after purification by FC on Si02 (cyclohexane/EtOAc 99:1 -÷98:2) as a light yellow oil.

1H NMR (CDCI3, 400 MHz); mixture of isomers: ö = 9.64 (d, J = 2.0 Hz, 1 H), 9.64 (d, J= 2.2 Hz, 1H), 9.62 (ci, J= 1.7 Hz, 1H), 9.60(d, J= 2.5 Hz, 1H), 4.73-4.71 (m, 2H), 4.70- 4.69 (m, 1H), 4.68-4.67 (m, 1H), 4.66-4.64 (m, 1H), 4.63-4.61 (m, 1H), 4.57-4.54 (m, 2H), 2.57-2.46(m, 3H), 2.42-2.34(m, 2H), 2.30-2.23 (m, 3H), 2.15-2.04 (m, 3H), 1.93- 1.65(m, 16H), 1.61-1.53(m, 3H), 1.50-1.13(m, 22H), 1.12(d, J= 7.1 Hz, 3H), 1.11 (d, J= 7.3 Hz, 3H), 1.10(d, J= 7.1 Hz, 3H), 1.10 (d, J= 7.1 Hz, 3H), 1.06-0.93 (m, 4H), 0.89-0.83 (m, 24H) ppm.

MS (El); sum of isomers: 222 (Mt, 4), 204 (12), 189 (5), 175 (16), 165 (14), 147 (100), 124 (19), 107 (78), 95(48), 91(51), 79(33), 67(20), 55(26), 41(39), 29(24).

Odour description: floral green, cyclal aspect, watery, creamy.

Example 14: 3-(4'-(tert-Butyl)-2'-methylenecyclohexyl)propanal According to Example la, the enamine of 3-(tert-butyl)cyclohexanone was alkylated with ethyl acrylate to give after distillation ethyl 3-(4'-(tert-butyl)-2'-oxocyclohexy- propanoate (32%, light pink oil), which was further converted into ethyl 3-(4'-(tert-butyl)- 2'-methylenecyclohexyl)-propanoate (75%, colorless oil) which was reduced to 3-(4'- (tert-butyl)-2'-methylenecyclohexypropan-1 -ol (87%, colorless oil). According to Example lb. starting from 3-(4'-(tert-buty-2'-methylenecyclohexyl)propan-1 -ol (3.39 g, 16.1 mmol), 2.16 g (64%) of the title compound was obtained after purification by FC on SiO2 (hexane/EtOAc 98:2 -, 95:5) as a colorless oil.

1H NMR (CDCI3, 400 MHz): 6 = 9.80 (t, J= 1.7 Hz, 1 H), 4.74-4.70 (m, 1 H), 4.55-4.54 (m, 1 H), 2.59-2.45(m, 2 H), 2.41-2.35(m, 1 H), 2.02-1.89(m, 2 H), 1.86-1.76(m, 2 H), 1.73-1.67 (m, 1 H), 1.65-1.55 (m, 1 H), 1.22-1.08 (m, 2 H), 1.02-0.98 (m, 1 H), 0.86 (s, 9 H) ppm.

13C-NMR (CDOI3, 100 MHz): ö = 202.7 (d), 152.6 (s), 104.5 (t), 50.5 (d), 42.1 (d), 41.9 (t), 38.3 (t), 34.2 (t), 32.4 (s), 27.4 (3q), 27.3 (t), 24.3 (1) ppm.

MS (El): 208 (Me, 5), 190 (8), 175(5), 164 (4), 151 (36), 133 (100), 19(14), 107 (38), 91(56), 79(31), 67(19), 57(70), 41(45), 29(18).

Odour: floral green, soft aldehydic.

Example 15: 3-(4'-(tert-Butyl)-2'-methylenecyclohexyl)-2-methylpropanal According to Example la, the enamine of 3-(tert-butyl)cyclohexanone was alkylated with ethyl methacrylate to give after distillation ethyl 3-(4'-(tert-butyl)-2'-oxocyclohexyl)- 2-methyl-propanoate (87%, light pink oil), which was further converted into ethyl 3-(4'- (tert-butyl)-2'-methylenecyclohexy-2-methylpropanoate (70%, colorless oil) which was reduced to 3-(4'-(tert-butyl)-2'-methylenecyclohexy-2-methyl-propan-1 -ol (95%, colorless oil). According to Example ib, starting from 3-(4'-(tert-butyl)-2'-methylenecyclohexyl)-2-methyl-propan-1 -ol (8.46 g, 37.7 mmol), 5.47 g (65%) of the title compound was obtained as a mixture of two diastereomers (ratio 7:3) after purification by EC on SiO2 (hexane/EtOAc 99:1 -98:2 -* 95:5) as a light yellow oil.

1H NMR (CDCI3, 400 MHz); mixture of isomers: S = 9.64 (d, J = 2.0 Hz, 1 H), 9.60 (d, i= 2.4 Hz, 1H), 4.74-4.71 (ni, 2H), 4.56-4.54 (m, 2H), 2.60-2.45 (m, 2H), 2.41-2.35 (m, 2H), 2.12-2.05(m, 1H), 1.97-1.79(m, 6H), 1.75-1.67 (m, 3H), 1.60-1.50 (m, 1H), 1.28- 1.21 (m, 1H), 1.19-1.08 (m, 4H), 1.12 (d, J= 7.1 Hz, 3H), 1.10 (d, J= 7.1 Hz, 3H), 1.02- 0.89 (m, 2H), 0.87 (s, 9H), 0.86 (s, 9H) ppm.

13C-NMR (CDCI3, 100 MHz); mixture of isomers: S = 205.2 (d), 205.2 (d), 153.0 (s), 152.9 (s), 104.6 (t), 104.5 (t), 50.7 (d), 50.6 (d), 43.9 (d), 43.8 (d), 40.0 (d), 39.9 (d), 38.4 (t), 38.4 (t), 34.7 (t), 34.1 (t), 33.4 (t), 32.8 (t), 32.5 (s), 32.5 (s), 27.4 (3q), 27.4 (3q), 27.3 (t), 27.3 (t), 14.4(q), 13.6 (q) ppm.

MS (El); sum of isomers: 222 (M, 6), 204 (8), 189 (8), 165 (38), 147 (100), 133 (15), 124 (28), 107 (53), 95(48), 91(53), 79(38), 67(22), 57(87), 41(58), 29(25).

Odour description: green, soft aldehydic.

Example 16: Fragrance Composition for shower gel Compound /lngredient parts by weight 1/1 000 Ethyl Linalool 55 8-(sec-Buty-5,6,7,8-tetrahydroquinoline (Bigaryl) (at 1% in DEP) 5 Ethyl 2-(2-methyl-1,3-dioxolan-2-yl)acetate (Fructone) 25 Allyl 2-(cyclohexyloxy)acetate (Cyclogalbanate) 5 Cyclal C (at 10% in TEC) 15 1 0-lsopropyl-2,7-dimethyl-1 -oxaspiro[4.5]deca-3,6-diene (Neocaspirene) (at 1% in DEE') 15 Methyl 2-(3-oxo-2-pentylcyclopentyacetate (Hedione) 220 Benzyl Acetate extra 15 Indole (at 1% in DEP) 15 Methyl Benzoate (at 1% in DEP) 7 (Z)-3-Methyl-2-(pent-2-enyl)cyclopent-2-enone (cis-Jasmone) 3 3-(Benzo[d][1,3]dioxol-5-yl)-2-methylpropanal (Tropional) 20 Galaxolide 150 3-Methylcyclopentadecenone (Muscenone) 10 3,7-Dimethyloct-6-en-1 -ol (Citronellol) 35 Phenyl Ethyl Alcohol 20 4-Allyl-2-methoxyphenol (Eugenol) 5 4-Methyl-2-(2-methylprop-1 -enyl)tetrahydro-2H-pyran (Rose Oxide) (at 10% in DEE') 5 2-(sec-Butycyclohexanone (Freskomenthe) 5 Iso E Super 25 3-Methyl-4-(2,6,6-trimethylcyclohex-2-en-1 -yl)but-3-en-2-one (Isoraldeine 95) 25 Ambrof ix 2 Javanol (at 10% in DEP) 8 Dipropylene glycol (DPG) 250 3-(4'-lsobutyl-2'-methylenecyclohexyDpropanal (Example 1 60 Total: 1000 3-(4'-lsobutyl-2'-methylenecyclohexypropanal reinforces the general floral character of the composition, brings a soft creamy watery aspect and adds thickness and body when assessed on neat and in bloom in water. The composition may be applied at iweight % to e.g. shower gel.

Claims (6)

1. Claims A compound of formula (I) R3 (I) wherein R1 and R2 are independently selected from hydrogen and methyl, and R3 is selected from hydrogen, C1 -C6 alkyl, C2 -C4 alkylidene, and C3 -C5 alkenyl.
2. 2. A compound according to claim 1 selected from the group consisting of 3-(4'-lsobutyl-2'-methylenecyclohexypropanal, 2-Methyl-3-(2'-methylenecyclohexypropanal, 3-(4'-Methyl-2'-methylenecyclohexypropanal, 2-Methyl-3-(4'-methyl-2'-methylenecyclohexyl)propanal, 3-(4' ,4'-Dimethyl-2'-methylenecyclohexyl)propanal, 3-(4' ,4'-Dimethyl-2-methylenecyclohexyl)-2-methylpropanal, 3-(4'-lsobutyl-2'-methylenecyclohexy-2-methylpropanal, 3-(4'-lsopropyl-2'-methylenecyclohexypropanal, 3-(4'-lsopropyl-2'-methylenecyclohexy-2-methylpropanal, 2-Methyl-3-(2'-methylene-4'-(prop-1 -en-2-yl)cyclohexyl)propanal, 3-(4'-(sec-Buty-2'-methylenecyclohexypropanal, 3-(4'-(sec-Buty-2'-methylenecyclohexy-2-methylpropanal, 3-(4'-(tert-butyl)-2'-methylenecyclohexyl)propanal, and 3-(4'-(tert-butyl)-2'-methylenecyclohexyfl-2-methylpropanal.
3. 3. The use as fragrance of a compound of formula (I) R3 (I) wherein R1 and R2 are independently selected from hydrogen and methyl, and R3 is selected from hydrogen, C1 -C6 alkyl, C2 -C4 alkylidene, and C3 -C5 alkenyl.
4. 4. A method of improving, enhancing or modifying a consumer product base by means of the addition thereto of a compound of formula (I) as defined in claim 1 or a mixture thereof.
5. 5. A fragrance composition comprising a. a compound of formula (I) as defined in claim 1, or a mixture thereof, and b. at least one known odorant.
6. 6. A fragranced article comprising a. a compound of formula (I) as defined in claim 1, or a mixture thereof, and b. a consumer product base.