WO2012069647A1

WO2012069647A1 - Novel 1h- spiro [naphtalene- 2, 2 ' -oxirane] derivatives

Info

Publication number: WO2012069647A1
Application number: PCT/EP2011/071066
Authority: WO
Inventors: Jerzy A. Bajgrowicz; Christopher Furniss
Original assignee: Givaudan Sa
Priority date: 2010-11-26
Filing date: 2011-11-25
Publication date: 2012-05-31
Also published as: GB201020070D0

Abstract

Compounds of formula (I), wherein R1 is hydrogen, methyl or ethyl, and R2 is methyl or ethyl, having woody and ambery odor notes, their use as fragrance ingredient and perfumed products comprising them.

Description

Organic compounds

The present invention refers to certain spiro[decaline-2,2-oxiranes] having woody and ambery odor notes and their use as odorants. This invention relates furthermore to a method of their production and flavor and fragrance compositions comprising them.

In modern perfumery woody, ambery notes play a decisive role. They form the foundation of a lot of perfumes, and it is difficult to imagine a perfume without any woody or ambery notes. A commercially important compound possessing woody, ambery odor notes is the cyclic ether (A) (3a,6,6,9a-tetramethyldodecahydro- naphtho[2,1-/b]furan, also known under trade names such as Ambrox^®, Ambroxan^®, Ambrofix^® or Cetalox^®) which is regarded as the prototype of ambergris odorants. Winter et al. (Helv. Chim. Acta 2004, 87, 1916) found that the spirocyclic ethers (B) and (C) related to the cyclic ether (A) also evoke the ambergris descriptor but that in particular the spirocyclic ether (C) possesses disturbing camphoraceous, cresolic side notes and is relatively less active. Furthermore, Winter et al. found that for (C) the a

(A) (B) (C) (C) Surprisingly, it has now been found that the methyl- and ethyl-substitution of the oxirane ring of (C) results in compounds possessing the highly appreciated ambergris-type, strong odor, devoid of any negative aspects.

Accordingly, there is provided in a first aspect the use as fragrance or flavor of a compound of formula (I)

wherein R¹ is hydrogen, methyl or ethyl, and R² is methyl or ethyl. The compounds of formula (I) comprise several chiral centers and as such may exist as racemates or any mixture of stereoisomers, or they may be resolved as

enantiomerically pure forms. Resolving enantiomers adds to the complexity of manufacture and purification of these compounds and so it is preferred to use the compounds as racemates or mixtures of their stereoisomers simply for economic reasons. However, if it is desired to prepare individual enantiomers, this may be achieved according to methods known in the art, e.g. preparative HPLC and GC, crystallization or by departing from chiral starting materials, e.g. starting from

enantiomerically pure or enriched raw materials such as sclareol, manool or larixol, and/or by applying stereoselective synthesis.

As a typical example one may cite {4aRS,8aSR)-3',5,5,8a-tetramethyloctahydro-1 H- spiro[naphthalene-2,2'-oxirane] possessing a powerful woody, ambery and gourmand note with slightly buttery and vetiver aspects. The gourmand, slightly buttery and vetiver aspects perfectly complement the woody and ambery main note without any negative effects. Furthermore, this compound has an odor threshold concentration which is 16 times lower when compared with its 3'-unsubstituted oxirane derivative (i.e. 5,5,8a- trimethyIoctahydro-1 H-spiro[naphthalene-2,2'-oxirane], compound C), and of the same order of magnitude as 3a,6,6,9a-tetramethyIdodecahydronaphtho[2,1-b]furan. The odor threshold concentration is defined as the lowest concentration of the vapor of an odorant material in the air which can be detected by smell and can be measured by standard methods known in the art. Further compounds of formula (I) are

S'-ethyl-S.S.Sa-trimethyloctahydro-I H-spiroInaphthalene^^'-oxirane],

1 ,3',5,5,8a-pentamethyloctahydro-1 H-spiro[naphthalene-2,2'-oxirane],

3'-ethyl-1 ,5,5,8a-tetramethyloctahydro-1H-spiro[naphthalene-2,2'-oxirane],

1 -ethyl-3',5,5,8a-tetramethyloctahydro-1 H-spiro[naphthalene-2,2'-oxirane], and

1 ,3'-diethyl-5,5,8a-trimethyloctahydro-1 H-spiro[naphthalene-2,2'-oxirane],

enantiomerically pure, racemates or any mixture of stereoisomers thereof. The compounds of formula (I) may be used alone, as mixtures thereof, 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. As used herein, "fragrance composition" means any composition comprising at least one compound of formula (I) and a base material, e.g. a diluent conventionally used in conjunction with odorants, such as dipropyienegiycol (DPG), isopropylmyristate (IPM), triethylcitrate (TEC) and alcohol (e.g. ethanol), and known odorants. The following list comprises examples of known odorant molecules, which may be combined with the compounds of the present invention:

- essential oils and extracts, e.g. tree moss absolute, basil oil, fruit oils such as bergamot oil and mandarine oil, myrtle oil, palmarose oil, patchouli oil, petitgnain oil, jasmine oil, rose oil, sandalwood oil, wormwood oil, lavender oil or ylang-ylang oil;

- alcohols, e.g. cinnamic alcohol, cis-3-hexenol, citronellol, Ebanol™, eugenol, farnesol, geraniol, Super Muguet™, linalool, menthol, nerol, phenylethyl alcohol, rhodinol, Sandalore™, terpineol or Timberol™;

- aldehydes and ketones, e.g. anisaldehyde, a-amylcinnamaldehyde, Georgywood™, hydroxycitronellal, Iso E^® Super, Isoraldeine^®, Hedione^®, Lilial^®, maltol, Methyl cedryl ketone, methylionone, verbenone or vanillin; - ethers and acetals, e.g. Ambrox™, geranyl methyl ether, rose oxide or

Spirambrene™;

- esters and lactones, e.g. benzyl acetate, Cedryl acetate, γ-decalactone, Helvetolide^®, γ-undeca lactone or Vetivenyl acetate; - macrocycles, e.g. Ambrettolide, Ethylene brassylate or Exaltolide ;

- heterocycles, e.g. isobutylquinoline. The compounds according to formula (I) may be used in a broad range of perfumed products, 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 compounds can be employed in widely varying amounts, depending upon the specific application and on the nature and quantity of other odorant ingredients. The proportion is typically from 0.0001 to 30 weight percent of the application. In one embodiment, compounds of the present invention may be employed in a fabric softener in an amount of from 0.0001 to 0.05 weight percent. In another embodiment, compounds of the present invention may be used in fine perfumery in amounts of from 0.01 to 30 weight percent, more preferably between 0.5 and 20 weight percent.

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, e.g. up to about 50 weight percent based on the perfumed product.

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

Thus, the invention additionally provides a method of manufacturing a perfumed product, 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 a compound of formula (I), which may then be mixed with a consumer product base, using conventional techniques and methods. Through the addition of an olfactorily acceptable amount of at least one compound of the present invention as hereinabove described the odor 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 at least one compound of formula (I).

The invention also provides a fragrance application comprising:

a) as odorant at least one compound of formula (I); and

b) a consumer product base.

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 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 and cosmetics, e.g.

deodorant, vanishing creme. 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 none of the compounds falling within the definition of formula (I) are described in the literature and are thus novel in their own right. Accordingly, the present invention refers in a further aspect to compounds of formula (I)

(I)

wherein R is hydrogen, methyl or ethyl, and R² is methyl or ethyl.

The compounds of formula (I) wherein R¹ is hydrogen may be prepared starting from known 5,5,8a-trimethyloctahydronaphthalen-2(1 H)-one (2a) which is transformed into alkylidenedecalin 3 via the Wittig reaction or other alkenylation method and epoxidised by MCPBA (m-chloroperbenzoic acid) or other suitable epoxidising agent e.g. peracetic acid or hydrogen peroxide. 1-AIkyl derivatives (i.e. compounds of formula (I) wherein R¹ = methyl, or ethyl) may be obtained via alkylation of the intermediate methyl 5,5,8a- trimethyl-2-oxodecahydronaphthalene-1-carboxylate (1a) using alkyl halides ( ¹X wherein X may be selected from I, CI, and Br in the presence of a base e.g. potassium carboxylate, sodium hydride or lithium hexamethyldisilazane. Hydrolysis and decarboxylation of such obtained ketoesters 1 b by e.g. heating in the presence of potassium hydroxide afford 1-alkyl-5,5,8a-trimethyloctahydronaphthalen-2(1 H)-ones 2b which are transformed into 1 -alkyl spirooxiranes I as described above for 1- unsubstituted analogues.

Further particulars as to reaction conditions are provided in the Examples.

Scheme 1 :

1b 2b a) KOH, Δ; b) Ph₃P(Br)CH_zR², KO'Bu; c) MCPBA; d) R¹X, base

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 dihydro-p-ionone, and are racemates or mixtures of racemates. Optically pure or enriched stereoisomers (enantiomers or mixtures of diastereomers) may be obtained by resolution of racemates or by asymmetric synthesis methodologies known to one skilled in the art. They may also be prepared using natural substrates e. g. sclareol, manool or larixol.

The reported NMR spectra were measured in CDCI₃ at 400 MHz if not otherwise stated; chemical shifts (δ) are reported in ppm downfield from TMS; coupling constants J in Hz. The GC/MS analyses were run using a DB-5 column. Flash chromatography:

Brunschwig silica gel 60 (32 - 63 mesh). Samples for olfactory evaluation were purified by bulb-to-bulb distillation. All purified products were isolated as colorless oils, the purity of which was measured by GC/MS.

Example 1 : (4aRS,8aSR)-3',5,5,8a-Tetramethyloctahydro-1 H-spiro[naphthalene-2,2'- oxirane] (la)

a) (4af?S,8aSR)-6-Ethylidene-1 ,1 ,4a-trimethyldecahydronaphthalene (3a)

(4aRS,8aSR)-5,5,8a-trimethyloctahydronaphthalen-2(1 H)-one (2a, Mukhopadhyay, S. K.; Dutta, P. C. J. Chem. Soc. C 1967, 1876), obtained from 1a in an analogous way as 2b in Example 2b, (89% pure, 2.5 g, 11 mmol), was dissolved in cyclohexane (25 ml) and stirred under nitrogen. Potassium ferf-butoxide (2 g, 7 mmol) and

ethyltriphenylphosphonium bromide (5.4 g, 14 mmol) were added sequentially and after stirring for 3 h at room temperature the reaction crude was poured onto hot water (60°C, 00 ml). Cyclohexane (50 ml) was added and after brief agitation the phases were separated. The organic phase was washed with 80% aqueous methanol (2 x 100 ml), dried (Na2S0₄) and the solvent removed in vacuo. 2.4 g of yellow oil were obtained which was purified by flash chromatography (hexane). Combination and solvent removal of pure fractions yielded 2.1 g of a colorless oil which was purified further by bulb-to-bulb distillation to afford 3a (1.8 g, >99% pure, 77% yield, 8:5 mixture of E/Z isomers).

Major isomer (4aRS,8aSR,£): ¹H NMR (C₆D₆): 5.13 (qt, J = 6.6, 2.0, 1 H), 2.70 (ddt, J = 13.5, 4.3, 2.0, 1 H), 1.85 (d, J = 12.4, 1 H), 1.72 (dd, J = 12.4, 2.0, 1 H), 1.60 (dt, J = 6.8, 1.6, 3H), 1.69 - 1.53 (m, 3H), 1 .44 - 1.33 (m, 3H), 1.22 - 1 .08 (m, 3H), 0.99 (dd, J = 12.4, 2.5, 1 H), 0.85 (2s, 6H), 0.79 (s, 3H). ¹³C NMR (C₆D₆): δ 137.4 (s), 117.0 (d), 56.0 (t), 54.0 (d), 42.9 (t), 42.3 (t), 36.2 (s), 33.3 (q), 33.2 (s), 29.0 (t), 23.0 (t), 21.6 (q) 19.5 (t), 19.5 (q), 12.8 (q). Minor isomer (4a RS, 8a SR,Z): ¹³C NMR (C₆D₆): δ 137.7 (s), 1 .0 (d), 54.3 (d), 46.9 (t), 42.9 (t), 42.5 (t), 38.2 (t), 36.6 (s), 33.3 (s), 33.3 (q), 24.1 (t), 21.6 (q) 19.6 (t), 19.1 (q), 12.9 (q). MS: Sum of both isomers: 206 (29, M⁺), 137 (100), 121 (28), 109 (34), 95 (61 ), 81 (53), 69 (35), 67 (32), 55 (36), 41 (40). b) (4aRS,8aSR)-3',5,5,8a-Tetramethyloctahydro-1 H-spiro[naphthalene-2,2'-oxirane] (la) (4aRS,8aSR)-6-ethyIidene-1 ,1 ,4a-trimethyldecahydronaphthalene (3a, 1.3 g, 6.3 mmol) was dissolved in dichloromethane (10 ml) and 3-chloroperbenzoic acid (77% pure, 2.1 g, 9.5 mmol) added portionwise with stirring and under nitrogen. Stirring at room temperature continued for 2 h, then 2M sodium hydroxide solution was added to pH of ca. 14. After brief agitation the phases were separated and the aqueous layer extracted with dichloromethane (50 ml). The combined organic phases were washed with 2M sodium hydroxide (50 ml) and water to pH 5 (2 x 50 ml), dried (Na2S0 ) and the solvent removed in vacuo. A pale yellow oil (1.2 g) was obtained which was purified by flash chromatography (hexane/MTBE 9:1 ) to give la (0.9 g, >99% pure, 74:48:3:2 mixture of diastereomers, 64% yield). Major diastereomer (2RS,3'RS,4aSR,8aRS): ¹H NMR (500 MHz, C₆D₆): δ 2.68 (qd, J =

5.6, 0.6, 1 H), 1 .68 (d, J = 12.4, H), 1.65 - 1.46 (m, 4H), 1.36 - 1.23 (m, 3H), 1.12 (d, J = 5.6, 3H), 1.12 (qd, J = 13.1 , 4.8, 1 H), 1 .08 (td, J = 14.4, 4.5, 1 H), 0.98 (td, J = 13.1 , 3.8, 1 H), 0.89 ( dd, J = 12.4, 2.3, 1 H), 0.80 (dd, J = 12.6, 2.8, 1 H), 0.80 (2s, 6H), 0.75 (s, 3H). ¹³C NMR (500 MHz, C₆D₆) δ 60.4 (d), 59.7 (s), 54.0 (t), 52.9 (d), 42.3 (t), 41 .7 (t), 36.2 (s), 33.1 (q), 32.8 (s), 30.1 (t), 21.5 (t), 21.3 (q), 19.5 (q), 18.8 (t), 13.7 (q). MS: 222 (19, M⁺), 207 (97), 123 (64), 109 (100), 95 (79), 81 (84), 69 (87), 67 (66), 55 (91), 43 (82), 41 (83).

Second major diastereomer (2RS,3'SR,4aSR,8aRS): ¹H NMR (500 MHz, C₆D₆): δ 2.65 (qd, J = 5.5, 0.6, 1 H), 1.85 (td, J = 13.3, 4.9, 1 H), 1.54 -1.46 (m, 2H), 1.44 (d, J = 13.1 , 1 H), 1.36 - 1.24 (m, 4H), 1.21 (dd, J = 13.1 , 2.4, 1 H), 1.16 (m, 1 H), 1 .10 (d, J = 5.5, 3H), 1.08 (td, J = 13.7, 4.7, 1 H), 0.98 (td, J = 13.2, 3.5, 1 H), 0.80 (s, 3H), 0.80 (dd, J = 12.5,

2.7, 1 H), 0.76 (2s, 6H). ¹³C NMR (500 MHz, C₆D₆) δ 61.5 (d), 60.4 (s), 53.2 (d), 46.8 (t), 42.5 (t), 42.2 (t), 37.4 (t), 36.2 (s), 33.4 (q), 33.1 (s), 21.8 (t), 21.7 (q), 19.4 (q), 19.1 (t), 15.6 (q). MS: 222 (20, M⁺), 207 (83), 123 (69), 109 (100), 95 (78), 81 (81 ), 69 (88), 67 (64), 55 (93), 43 (88), 41 (86).

Odor: woody, ambery, gourmand, slightly buttery, vetiver.

Example 2 - Comparison Example: (4aSR,8aSR)-1 ,5,5,8a-Tetramethyloctahydro-1 H- spiro[naphthaIene-2,2'-oxirane] (lb)

a) (4aRS,8aRS)-Methyl 1 ,5,5,8a~tetramethyl-2-oxodecahydronaphthalene-1- carboxylate (1 b)

Sodium hydride 60% in mineral oil (1.6 g, 39 mmol) was suspended in

dimethylformamide (225 ml). The suspension was stirred under nitrogen while

(1 RS, 4a SR,8aSR)-m ethyl 5,5,8a-trimethyl-2-oxodecahydronaphthalene-1-carboxylate (1a, 10 g, 39 mmol), obtained according to Laube, T.; Schroeder, J.; Stehle, R.; Seifert, K. Tetrahedron 2002, 58, 4299, was added over 20 min. Once hydrogen formation ceased, methyl iodide (12.4 g, 86 mmol) was added in one portion and the reaction heated to 60°C. After stirring for 72 h the reaction mixture was cooled and poured onto ice-water (400 ml). Diethyl ether (400 ml) was added and the suspension stirred until the phases became clear. The phases were separated and the aqueous layer extracted with diethyl ether (200 ml). The combined organic phases were washed with water (2 x 200 ml), dried (Na₂S0 ) and the solvent removed in vacuo. 1 b was obtained as a mixture (46%) with starting material (yellow oil, 9.5 g, 42% yield). 3C NMR δ 210.1 (s), 171.5 (s), 66.5 (s), 51.5 (q), 44.2 (d), 41.7 (t), 41.7 (s), 37.1 (t), 34.1 (t), 34.1 (q), 33.6 (s), 22.2 (q), 21.7 (t), 19.1 (q), 18.6 (q), 18.3 (t). MS: 266 (3, M⁺), 137 (100), 123 (89), 109 (83), 95 (87), 88 (61 ), 81 (89), 69 (75), 67 (60), 55 (94), 41 (91). b) (1 RS,4aSR,8aSR)-1 ,5,5,8a-Tetramethyloctahydronaphthalen-2(1 H)-one (2b)

Potassium hydroxide (23.7 g, 420 mmol) was dissolved in water (200 ml) and the crude (4aRS,8a RS)-methyl 1 ,5,5, 8a-tetramethyl-2-oxodecahyd rona phtha le ne-1 -ca rboxylate (1 b, 32 g, ca. 40% pure, 48 mmol) added as a solution in ethanol (200 ml). The reaction mixture was heated to 120°C with stirring and under nitrogen. After stirring for 60 h at this temperature the reaction was cooled and poured onto ice. The product was extracted twice with MTBE and the organic phases washed with water and brine, dried (MgS0₄), concentrated in vacuo and purified by flash chromatography (hexane/MTBE 20:1 ) to give 2b (6.2 g, 76% pure, 47% yield).

The analytical data of 2b are identical with those reported in the literature: Tatee, T.; Tsuyuki, T.; Aoyagi, R; Takahashi, T. Bull. Chem. Soc. Japan 1974, 47, 3158. c) (4aRS,5SR,8aSR)-1 ,1 ,4a,5-Tetramethyl-6-methylenedecahydronaphthalene (3b) Potassium ferf-butoxide (2.5 g, 22 mmol) and methyltriphenylphosphonium bromide (6.3 g, 17 mmol) were added sequentially, under nitrogen, to a stirred solution of (1 RS,4aSR,8aSR)-1 ,5,5,8a-tetramethyloctahydronaphthalen-2(1 H)-one (2b, 76%, 3g, 11 mmol) in cyclohexane (60 ml). After an additional 30 min. stirring at room

temperature the reaction mixture was poured onto hot water (60°C, 100 ml) and extracted with hexane (50 ml). The organic phase was washed with 80% aqueous methanol (50 ml), dried (Na₂S0₄) and the solvent removed in vacuo to give 3 g of crude product. Purification by flash chromatography (hexane/MTBE 20:1) yielded 3b

(colorless oil, 2.1 g, 98% pure, 93% yield). H NMR: δ 4.71 (tdd, J = 2.0, 1.8, 0.5, 1 H), 4.51 (q, J = 1.8, 1 H), 2.13 (ddd, J = 12.9, 4.3, 2.3, 1 H), 2.05 (td, J = 13.2, 5.5, 1 H), 1 .81 (td, J = 7.2, 6.9, 1 H), 1 .73 - .82 (m, 2H), 1.55 (qt, J = 13.4, 3.3, 1 H), 1.49 - 1.43 (m, 1 H), 1.40 (m, 1 H), 1.31 (td, J = 12.9, 4.4, 1 H), 1.19 (td, J = 13.3, 3.9, 1 H), 1.11 (dd, J = 12.6, 2.8, 1 H), 1.04 (td, J = 12.9, 4.0, 1 H), 0.89 (d, J = 6.8, 3H), 0.88 (s, 3H), 0.82 (s, 3H), 0.67 (s, 3H). ³C NMR: δ 151.8 (s), 105.7 (t), 55.3 (d), 50.3 (d), 42.2 (t), 39.4 (t), 38.8 (s), 37.4 (t), 33.6 (q), 33.5 (s), 23.9 (t), 21.8 (q), 19.3 (t), 13.3 (q), 10.4 {q). MS: 206 (19, M÷), 191 (31), 137 (100), 123 (33), 109 (36), 95 (65), 81 (54), 69 (38), 67 (35), 55 (31 ), 41 (36). d) (4aRS,8aRS)-1 ,5,5,8a-Tetramethyloctahydro-1H-spiro[naphthalene-2,2'-oxirane] (lb) Using experimental conditions analogous to those given in Example 1 b, 3b (1.9 g, 9 mmol) was converted to lb (1.5 g, >99% pure, 23:1 :1 diastereomer mixture, 73% yield).

Major diastereomer (1 RS,2RS,4aSR,8aSR): H NMR: δ 2.72 (ddd, J = 4.6, 2.0, 0.5, 1 H), 2.50 (dd, J = 4.6, 0.8, 1 H), .89 (m, 1 H), 1.78 (m, 1 H), 1.66 - 1.37 (m, 6H), 1.64 (q, J = 7.1 , 1 H), 1.18 (td, J = 13.5, 4.5, 1 H), 1.06 - 0.95 (m, 1 H), 1.03 (dd, J = 12.6, 2.8, 1 H), 0.90 (s, 3H), 0.85 (s, 3H), 0.81 (s, 3H), 0.60 (d, J = 7.1 , 3H). ¹³C NMR: 5 59.2 (s), 54.8 (d), 50.9 (t), 47.9 (d), 42.0 (t), 39.3 (t), 38.9 (s), 35.9 (t), 33.5 (q), 33.0 (s), 21.8 (q), 21.7 (t), 18.7 (t), 13.6 (q), 5.7 (q). MS : 222 (16, M⁺), 137 (50), 123 (65), 109 (95), 95 (100), 81 (91 ), 79 (44), 69 (83), 67 (63), 55 (82), 41 (72).

Odor: woody, ambery, slightly iso E super.

Example 3: (4aSR,8aSR)-1 ,3',5,5,8a-Pentamethyloctahydro-1 H-spiro[naphthalene-2,2'- oxirane] (lc)

a) (4aRS,5Sf?,8aSR,£)-6-Ethylidene-1 ,1 ,4a,5-tetramethyldecahydronaphthalene (3c) Using experimental conditions analogous to those given in Example 1a, 2b (76% pure, 3 g, 11 mmol) was converted to 3c (2.1 g, 97% pure, 84% yield).

¹H NMR (C₆D₆): δ 5.02 (qt, J = 6.6, .5, 1 H), 2.76 (m, 1 H), 5.02 (q, J = 7.0, 1 H), 1.73 - 1.42 (m, 5H), 1.61 (dt, J = 6.7, 1.5, 3H), 1.39 (m, 1 H), 1.31 - 1.14 (m, 2H), 1.11 (dd, J = 12.9, 2.8, 1 H), 1.03 (td, J = 12.9, 4.5, 1 H), 0.88 (s, 3H), 0.84 (d, J = 6.8, 3H), 0.81 (s, 3H), 0.62 (s, 3H). ¹³C NMR (C₆D₆): δ 141.5 (s), 113.9 (d), 55.9 (d), 51.2 (d), 42.6 (t), 39.7 (t), 39.3 (s), 33.7 (q), 33.5 (s), 29.9 (t), 23.6 (t), 22.0 (q)_r 19.7 (t), 13.5 (q), 13.0 (q), 10.6 (q). MS: 220 (17, M⁺), 137 (100), 136 (25), 123 (25), 109 (27), 95 (47), 81 (42), 69 (22), 67 (30), 55 (26), 41 (26). b) (4aSR,8aSR)-1 ,3',5,5,8a-Pentamethyloctahydro-1 H-spiro[naphthalene-2,2'-oxirane3 (Ic)

Using experimental conditions analogous to those given in example 1 b, 3c (1.9 g, 9 mmol) was converted to lc (1.7 g, >99% pure, 36:1 :1 diastereomer mixture, 84% yield).

Major diastereomer (1 RS,2RS,3'RS,4aSR,8aSR): ¹H NMR (C₆D₆, 500 MHz): δ 2.76 (q, J = 5.5, 1 H), 1.68 - 1.60 (m, 2H), 1 .58 (q, J = 7.1 , 1 H), 1.56 - 1 .40 (m, 3H), 1.37 - 1.30 (m, 2H), 1.17 {m, 1 H), 1.1 1 (d, J = 5.5, 3H), 1.10 -1.02 (m, 1 H), 0.88 - 0.75 (m, 1 H), 0.84 (dd, J = 12.8, 3.0, 1 H), 0.82 (s, 3H), 0.79 (s, 3H), 0.67 (d, J = 7.1 , 3H), 0.64 (s, 3H). ¹³C NMR (C₆D₆, 500 MHz): δ 61.6 (s), 55.2 (d), 53.9 (d), 49.7 (d), 42.2 (t), 39.1 (t), 38.9 (s), 33.6 (q), 33.3 (s), 31 .4 (t), 21.9 (q), 21.8 (t), 19.1 (t), 13.5 (q), 13.3 (q), 5.7 (q). MS : 236 (8, M⁺), 123 (67), 109 (100), 107 (57), 95 (99), 81 (95), 79 (52), 69 (93), 67 (69), 55 (86), 41 (79). Odor: woody, ambery, powdery, sawdust. Example 4: (4af?S,8aSR)-3'-Ethyl-5,5,8a-trimethylocta ydro-1H-spiro[naphthalene- 2,2'-oxirane] (Id)

a) (4af?S,8aSR)-1,1 ,4a-Trimethyl-6-propy!idenedecahydronaphthaiene (3d)

Using experimental conditions analogous to those given in Example 1a, and

propyltriphenylphosphonium bromide (5.6 g, 14 mmol) instead of

ethyltripheny!phosphonium bromide, 2a (2.5 g, 89% pure, 11 mmol) was converted to 3d (2.1 g, >99% pure, 7:3 mixture of EfZ isomers, 83% yield) Major isomer (£): ¹³C NMR δ 136.0 (s), 124.7 (d), 55.6 (t), 54.0 (d), 42.7 (t), 42.1 (t),

36.0 (s), 33.2 (q), 33.1 (s), 29.1 (t), 23.0 (t), 21.5 (q), 20.4 (t), 19.2 (t), 19.2 (q), 14.9 (q). MS: 220 (30, M⁺), 137 (100), 123 (31), 109 (31 ), 95 (55), 81 (55), 69 (32), 67 (34), 55 (41), 41 (40). Minor isomer (Z): ³C NMR δ 136.2 (s), 124.7 (d), 54.2 (d), 46.9 (t), 42.7 (t), 42.3 (t),

37.8 (t), 36.1 (s), 33.2 (q), 33.2 (s), 23.8 (t), 21 .5 (q), 20.4 (t), 19.2 (t), 19.1 (q), 14.7 (q). MS: 220 (31 , M⁺), 137 (100), 123 (36), 109 (33), 95 (59), 81 (59), 69 (36), 67 (38), 55 (48), 41 (48). b) (4af?S,8aSf?)-3'-Ethyl-5,5,8a-trimet yloctahydro-1 H-spiro[naphthalene-2,2'-oxirane] (Id)

Using experimental conditions analogous to those given in example 1 b, 3d (1.4 g, 6 mmol) was converted to Id (1.0 g, >99% pure, 44:13:1 :1 mixture of diastereomens, 64% yield).

Major diastereomer (2RS,3'RS,4aS/?,8aRS): ¹H NMR (C₆D₆): δ 2.57 (t, J = 6.3, 1 H), 1.69 (d, J = 12.4, H), 1.67 - 1.36 (m, 6H), 1.36 - 1.24 (m, 3H), 1.17 (m, 1 H), 1.08 (m, 1 H), 0.97 (m, 1 H), 0.94 (t, J = 7.6, 3H), 0.93 (dd, J = 12.4, 2.0, 1 H), 0.85 (s, 3H), 0.82 (dd, J = 13.9, 2.8, 1 H), 0.80 (s, 3H), 0.75 (s, 3H). ¹³C NMR: δ 67.4 (d), 61.1 (s), 53.8 (t), 53.2 (d), 42.4 (t), 41.8 (t), 36.5 (s), 33.2 (q), 33.0 (s), 30.0 (t), 21.9 (t), 21.7 (t), 21.4 (q), 19.6 (q), 18.6 (t), 10.6 (q). MS: 236 (15, M⁺), 221 (68), 123 (69), 109 (100), 95 (88), 81 (83), 69 (96), 67 (64), 57 (76), 55 (96), 41 (93). Second major diastereomer: ¹³C NMR: δ 68.5 (d), 61.8 (s), 53.3 (d), 46.9 (t), 42.3 (t), 42.1 (t), 37.1 (t), 36.1 (s), 33.3 (q), 33.0 (s), 22.8 (t), 21.5 (t), 21.5 (q), 19.5 (q), 18.8 (t), 10.9 (q). MS: 236 (14, M⁺), 221 (48), 123 (70), 109 (94), 95 (85), 81 (79), 69 (97), 67 (60), 57 (80), 55 (100), 41 (99).

Odor: Woody, ambery.

Example 5: GC-Odor threshold concentration

Different dilutions of a tested compound were injected into a GC in descending order of concentration until a panelist failed to detect the respective substance at the sniffing port. The panelist smelled in a blind trial and pressed a button upon perceiving an odor.

If the recorded time matched the retention time, the sample was further diluted. The last concentration detected at the correct retention time is the individual odor threshold concentration. The relative concentrations of several compounds are listed in Table 1 below. The value of the odor threshold concentration of the compound possessing the lowest odor threshold has been taken as 1.0.

Table 1 : Relative odor threshold concentration

Example 6: Woodv/amberv muskv perfuminq composition (unisex)

Inaredient parts per weicjht

Cashmeran (1 ,1 ^.S.S-pentamethyl^S.ej-tetrahydro-l H-inden-4(5H)-one) 90

Dihydromyrcenol 45

Ethyl Vanilline @10%DPG 3

Evemyl (methyl 2,4-dihydroxy-3,6-dimethylbenzoate) 30

Fixolide (l-fS.S.S.e.e.S-hexamethyl-S.e.Z.S-tetrahydronaphthalen^-y ethanone) 90

Isoraldeine 40¹⁾ 45

Nirvanolide (13-methy[oxacyclopentadec-10-en-2-one) 75

Pashminol (1-methyl-2-[(2,2,3 trimethylcyclopentyl)methyl]cyclopropanemethanol) 120

Petalia (alpha-cyclohexylidene-2-methyl-benzeneacetonitrile) 13

Raspberry Ketone (4-{4-hydroxyphenyl)butan-2-one) 15

Sandela (4-(5,5,6-trimethylbicyclo[2.2.1]hept-2-yl)cyclohexan-1-ol) 75

Timberol (1 -(2,2,6-trimethylcyclohexyl)hexan-3-ol) 25

Toscanol @10%DPG (1-cyclopropylmethyl-4-methoxybenzene) 4

3',5,5,8a-Tetramethyloctahydro-1 H-spiro[naphthalene-2,2'-oxirane] (la) 65

Dipropvlene Glycol (DPG) 135

TOTAL 000

Addition of 65 parts (ppt) of compound la enhances the woody/ambery facet of the above composition, conferring more texture and warmth of agarwood-type. It boosts the volume and increases substantivity while letting the floral, powdery notes be more present in the dry-down.

1) 3:2 mixture of 1-(2,6,6-trimethylcyclohex-1(2)-en-1-yl)pent-1-en-3-one and

3-methyl-4-(2,6,6-trimethyIcycIohex-1 (2)-en-1-yI)but-3-en-2-one; origin Givaudan, Switzerland

Claims

1 . A compound of formula (I)

wherein R¹ is hydrogen, methyl or ethyl, and

R² is methyl or ethyl.

2. A compound according to claim 1 selected from the list consisting of

S'.S.S.ea-tetramethyloctahydro-I H-spirotnaphthalene^^'-oxirane],

S'-ethyl-S.S.ea-trimethyloctahydro-I H-spirotnaphthalene^^'-oxirane],

1 ,3',5,5,8a-pentamethyloctahydro-1 H-spiro[naphthalene-2,2'-oxirane],

3'-ethyl-1 ,5,5,8a-tetram9thyloctahydro-1 H-spiro[naphthalene-2,2'-oxirane],

1-ethyI-3',5,5,8a-tetramethyloctahydro-1 H-spiro[naphthalene-2,2'-oxirane], and 1 ,3'-diethyl-5,5,8a-trimethy!octahydro-1 H-spiro[naphthalene-2,2'-oxirane].

3. The use as flavor or fragrance of a compound of formula (I)

(I)

wherein R¹ is hydrogen, methyl or ethyl, and

R² is methyl or ethyl.

4. A fragrance composition or a perfumed product comprising at least one compound of formula (I)

wherein R is hydrogen, methyl or ethyl,

R² is methyl or ethyl. A perfumed product according to claim 4 wherein the perfumed product is selected from fine perfumery, fabric care, household products, personal care products, and air care products.

A method of improving, enhancing or modifying a consumer product base comprising the step of adding thereto an olfactorily acceptable amount of at least one compound of formula (I)

wherein R is hydrogen, methyl or ethyl,

R² is methyl or ethyl.