Method for producing oxacyclohexane or oxacyclopentane derivatives

Abstract

The present invention relates to the field of organic synthesis, and more particularly to a process for the preparation of cycloethers of formula (I), comprising the cyclization of compounds of formula (II) in the presence of a heterogeneous acidic catalyst.

Description

[Technical field]

[0001] Technical Field The present invention relates to the field of organic synthesis, and more particularly to a process for the preparation of cycloethers of formula (I) comprising the cyclization of compounds of formula (II) carried out in the presence of a heterogeneous acidic catalyst.

[0002] background Cycloether derivatives represent highly desirable scaffolds and can be used as such or as key intermediates useful for the preparation of more complex compounds in different fields such as fragrance, cosmetics, pharmaceuticals or agrochemicals, among others. Relevant cycloether derivatives in the fragrance industry are, for example, Cetalox® (3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan; manufacturer: Firmenich SA, Geneva, Switzerland) or Ambrox® ((3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan; manufacturer: Firmenich SA, Geneva, Switzerland), which are the main components of natural ambergris. These perfuming ingredients represent some of the most sought-after ingredients in the fragrance industry. Several alternative methods for the preparation of Cetalox® or Ambrox® have been developed, in particular via cyclization of 2-(5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol as the last step. It has been disclosed that cyclization under acidic conditions results in low yields or low selectivity due to isomerization of the double bond of the starting material or formation of undesired diastereoisomers.

[0003] On the other hand, today there is a need to promote sustainable processes using recyclable catalysts, for example heterogeneous catalysts. The cyclization reaction of 2-(5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol in the presence of heterogeneous catalysts to produce Cetalox® or Ambrox® has not been reported so far.

[0004] Therefore, there remains a need to develop a sustainable cyclization process in the presence of small amounts of heterogeneous catalysts while improving conversion and selectivity.

[0005] The present invention makes it possible to solve the above problems by using a heterogeneous acidic catalyst to prepare the cycloethers of formula (I). To the best of the inventors' knowledge, the conditions of the present invention have not been reported in the prior art.

[0006] Summary of the Invention The present invention relates to a novel process which allows the preparation of cycloethers of formula (I) by cyclization of compounds of formula (II) in the presence of small amounts of heterogeneous acidic catalysts, which has not been reported or suggested in the prior art.

[0007] Thus, a first subject of the present invention is a compound of formula (I) [ka] [In the formula, m is 1 or 2; R 1 is a hydrogen atom or C 1~3 represents an alkyl group, Each R 2 , R 3 , R 4 C optionally containing, separately and independently of each other, a hydrogen atom or one or two functional groups selected from among an ether, ester, carbonyl, amine, amide or alcohol group 1~18 Represents an alkyl group; R 1 and R 2 C optionally containing, together, one or two functional groups selected from among ether, ester, carbonyl, amine, amide or alcohol groups; 2~11 represents an alkanediyl group, and / or R 2 and R 3 Together, C 1~11 represents an alkanediyl group, and / or R 3 and R 4 Together, C4~9 represents an alkanediyl group, and / or R 1 and R 4 Together, C 2~9 represents an alkanediyl group; R 5 is a hydrogen atom or C 1~3 The present invention relates to a method for producing a cycloether of the formula (II) [ka] [In the formula, m, R 1 , R 2 , R 3 , R 4 and R 5 has the same meaning as defined above] in the form of any one of its stereoisomers or a mixture thereof in the presence of a heterogeneous acidic catalyst.

[0008] A second subject of the invention is a) at least 95% (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan; b) at most 5% of (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan wherein the percentages are based on the total weight of the composition.

[0009] Description of the Invention Surprisingly, it has now been found that the cyclization of compounds of formula (II) in the presence of small amounts of heterogeneous acidic catalysts allows the preparation of compounds of formula (I) in high yield and with high selectivity. The process of the invention makes it possible to limit or even prevent the isomerization of double bonds at more stable positions, i.e. at terminal positions, while maintaining or improving the formation of the desired isomer, i.e. limiting the formation of undesired diastereoisomers.

[0010] Thus, a first subject of the present invention is a compound of formula (I) [ka] [In the formula, m is 1 or 2; R 1 is a hydrogen atom or C 1~3 represents an alkyl group; Each R 2 , R 3 , R 4 C optionally containing, separately and independently of each other, a hydrogen atom or one or two functional groups selected from among an ether, ester, carbonyl, amine, amide or alcohol group 1~18 Represents an alkyl group; R 1 and R 2 C optionally containing, together, one or two functional groups selected from among ether, ester, carbonyl, amine, amide or alcohol groups; 2~11 represents an alkanediyl group, and / or R 2 and R 3 Together, C 1~11 represents an alkanediyl group, and / or R 3 and R 4 Together, C 4~9 represents an alkanediyl group, and / or R 1 and R 4 Together, C 2~9 represents an alkanediyl group; R 5 is a hydrogen atom or C 1~3 The present invention relates to a method for producing a cycloether of the formula (II) [ka] [In the formula, m, R 1 , R 2 , R 3 , R 4 and R 5has the same meaning as defined above] in the form of any one of its stereoisomers or a mixture thereof in the presence of a heterogeneous acidic catalyst.

[0011] For clarity, the phrase "any one of its stereoisomers or a mixture thereof" or similar phrases means the usual meaning understood by a person skilled in the art, i.e., that the compounds referred to in the present invention may be pure enantiomers or mixtures of enantiomers. In other words, the compounds referred to in the present invention may have at least one stereocenter that may have two different stereochemistries (e.g., R or S), e.g., R 2 The group may contain at least one stereocenter. The compounds may be in the form of pure enantiomers or in the form of a mixture of enantiomers. The compounds referred to in the present invention may be in the form of pure diastereoisomers or in the form of a mixture of diastereoisomers if the compounds have two or more stereocenters. The compounds may be in racemic or scalemic form. Thus, the compounds may be in the form of one stereoisomer or in the form of a composition that includes or consists of various stereoisomers.

[0012] The term "optionally" is understood to mean that a group may or may not include a particular functional group.

[0013] The terms "alkyl" and "alkanediyl" are understood to include linear, branched, cyclic or alicyclic alkyl and alkanediyl groups.

[0014] The term "...optionally containing one or two functional groups selected from among ether, ester, carbonyl, amine, amide or alcohol groups" is understood to mean that these groups can either replace a hydrogen atom of an alkyl group and thus be laterally attached to said alkyl group or replace a carbon atom of an alkyl group (if chemically possible) and thus be inserted into the alkyl chain. For example, the -CH2-CH2-CHOH-CH2- group represents a C4 alkyl group containing an alcohol group (substitution of a hydrogen atom), the -CH2-CH2-COO-CH2-CH2-OCO-CH2-CH2- group represents a C6 alkyl group containing two ester groups (substitution of a carbon atom / insertion into the alkyl chain), and similarly the -CH2-CH2-O-CH2-CH2-O-CH2-CH2- group represents a C6 alkyl group containing two ether groups.

[0015] "···R 1 and R 2 Together,...C 2~11 represents an alkanediyl group, and / or R 2 and R 3 Together, C 1~11 represents an alkanediyl group, and / or R 3 and R 4 taken together represent , and / or R 1 and R 4 It is understood that, taken together, the above groups may form a (poly)cyclic alkyl group by "..." or similar expressions. In other words, compound (II) may be acyclic, monocyclic, bicyclic or tricyclic, and compound (I) may be monocyclic, bicyclic, tricyclic or tetracyclic. For example, R 2 and R 3 , and R 3 and R 4 When taken together, the compound of formula (II) contains a bicyclic moiety such as decalin. For example, R 2 , R 3 and R 4 taken together represent an alkanetriyl.

[0016] According to a particular embodiment, the compound of formula (II) is represented by the formula (II) and the formula (II') [ka] [In the formula, m, R 1 , R 2 , R 3 , R 4 and R 5 has the same meaning as defined above]. In particular, the compound of formula (II) may be in the form of a composition comprising a compound of formula (II) and a compound of formula (II'). In particular, the compound of formula (II) may be in the form of a composition comprising at least 50% of the compound of formula (II) and at most 50% of the compound of formula (II'), the percentages being relative to the total weight of the composition. In particular, the compound of formula (II) may be in the form of a composition comprising at least 60% of the compound of formula (II) and at most 40% of the compound of formula (II'). In particular, the compound of formula (II) may be in the form of a composition comprising at least 70% of the compound of formula (II) and at most 30% of the compound of formula (II'). In particular, the compound of formula (II) may be in the form of a composition comprising at least 80% of the compound of formula (II) and at most 20% of the compound of formula (II'). In particular, the compound of formula (II) may be in the form of a composition comprising at least 90% of the compound of formula (II) and at most 10% of the compound of formula (II'). In particular, the compound of formula (II) may be in the form of a composition comprising at least 95% of the compound of formula (II) and at most 5% of the compound of formula (II'). In particular, the compound of formula (II) may be in the form of a composition comprising at least 98% of the compound of formula (II) and at most 2% of the compound of formula (II'). In particular, the compound of formula (II) may be in the form of a composition comprising at least 99% of the compound of formula (II) and at most 1% of the compound of formula (II'). In particular, the compound of formula (II) may be in the form of a composition comprising at least 99.5% of the compound of formula (II) and at most 0.5% of the compound of formula (II'). Even more particularly, the compound of formula (II) does not include the compound of formula (II').

[0017] According to any embodiment of the present invention, the heterogeneous acidic catalyst may be amorphous or crystalline, in particular crystalline.

[0018] According to certain embodiments of the present invention, the heterogeneous acidic catalyst may be an acidic resin.Non-limiting examples of suitable acidic resins may include A-15 dry, A-35 dry, A-36 dry sold by Dupont.

[0019] According to any embodiment of the present invention, the heterogeneous acidic catalyst comprises silicon, tin, zirconium, hafnium or titanium and a second metal selected from the group consisting of aluminum, boron, iron or mixtures thereof. In particular, the heterogeneous acidic catalyst may be an aluminosilicate catalyst. In particular, the aluminosilicate catalyst may be a zeolite or a clay.

[0020] According to any embodiment of the present invention, commercially available clays may contain water. The water may be partially or completely removed before use. Those skilled in the art are familiar with methods of removing water, such as azeotropic distillation, vacuum removal or heating under a stream of nitrogen.

[0021] According to any embodiment of the present invention, the clay may be naturally occurring.In particular, the clay is an acid-treated clay.Non-limiting examples of suitable clays may include F-20X, F20-XLM, F-21X, F-24X, F-22, F-118FF currently sold by EP Minerals, Fulcat-22F and Fulcat-22B sold by Byk, and K-5, K-10-S300, K-20, K-21, K-30, K-41 sold by Clariant.

[0022] According to any embodiment of the present invention, the zeolite is a large pore zeolite.

[0023] The term "large pore zeolite" refers to its usual meaning in the art, ie, a 12-ring zeolite having pore sizes falling within the range between 6.0 Angstroms and 7.5 Angstroms.

[0024] According to any embodiment of the present invention, the zeolite has the FAU, BEA and MOR topology. In particular, the zeolite has the FAU topology.

[0025] According to any embodiment of the invention, the silicon:aluminum ratio is comprised in the range between 2.5:1 and 300:1. In particular, the silicon:aluminum ratio is comprised in the range between 5:1 and 150:1. In particular, the silicon:aluminum ratio is comprised in the range between 10:1 and 150:1. Even more particularly, in particular, the silicon:aluminum ratio is comprised in the range between 10:1 and 70:1.

[0026] According to any embodiment of the invention, the zeolite is used in its proton form. The latter can be provided directly by the manufacturer and used as such, or can be obtained, if necessary, by calcining an ammonium exchanger. In particular, the zeolite can be preactivated before the reaction. Preactivation can be carried out by heating the zeolite at a temperature comprised between 300° C. and 600° C. for at least 1 hour.

[0027] Non-limiting examples of suitable zeolites can include CBV720, CBV760, CBV780 currently sold by Zeolyst Corporation.

[0028] Heterogeneous acid catalysts can be added to the reaction medium of the process of the invention to form the cycloethers of formula (I) in a wide range of concentrations. As non-limiting examples, values ​​of the heterogeneous acid catalyst concentration can be mentioned ranging from 0.5% to 20% by weight, relative to the total amount of cycloethers of formula (I). In particular, the heterogeneous acid catalyst concentration can be comprised between 1% and 15% by weight. Even more particularly, the heterogeneous acid catalyst concentration can be comprised between 3% and 10% by weight. It goes without saying that the process also works with more catalyst. However, the optimum concentration of the heterogeneous acid catalyst will depend, as the skilled person knows, on the nature of the latter, on the nature of the substrate, on the temperature and on the desired reaction time.

[0029] Heterogeneous acid catalysts are commercially available compounds or can be prepared by several methods, such as those reported in US20040141911, US6054113, US4840930, US2470872 and EP0398636.

[0030] According to any one of the embodiments of the present invention, the inventive process for preparing cycloethers of formula (I) is carried out at a temperature comprised between 0° C. and 150° C. In particular, the temperature ranges between 30° C. and 70° C. Of course, the skilled person can also select the preferred temperature depending on the melting and boiling points of the starting materials and the final product as well as the desired reaction time, conversion or selectivity.

[0031] The process of the present invention for preparing cycloethers of formula (I) can be carried out in the presence or absence of a solvent. If a solvent is required or used for practical reasons, any current solvent for such reaction types can be used for the purposes of the present invention. Non-limiting examples include: 6~12Examples of suitable solvents include aromatic solvents such as xylene, toluene, 1,3-diisopropylbenzene, cumene pseudocumene, anisole or chlorobenzene or mixtures thereof, hydrocarbon solvents such as cyclohexane, heptane or mixtures thereof, nitrile solvents such as acetonitrile, ester solvents such as ethyl acetate or ether solvents such as tetrahydrofuran, diethyl ether, methyltetrahydrofuran or mixtures thereof. The choice of solvent depends on the nature of the substrate and / or catalyst, and the skilled person is well able to select the most suitable solvent in each case to optimize the reaction.

[0032] The process of the present invention for preparing cycloethers of formula (I) may be carried out under batch or continuous conditions.

[0033] The process of the invention for preparing cycloethers of formula (I) may be carried out at atmospheric pressure or at slightly reduced pressure.

[0034] According to any one of the embodiments of the present invention, the cycloether of formula (I) is a polycyclic compound. The term "polycyclic compound" is understood to mean that the compound of formula (I) contains at least two rings, for example, the cycloether of formula (I) is a bicyclic compound. In particular, the cycloether of formula (I) may be a bicyclic, tricyclic, tetracyclic or pentacyclic compound. Even more specifically, the cycloether of formula (I) may be a fused bicyclic, tricyclic or tetracyclic compound.

[0035] According to any one of the above embodiments of the present invention, the cycloether of formula (I) is a C9-C 20 It is a compound.

[0036] According to any one of the above embodiments of the present invention, R 1 is a hydrogen atom or C 1~3 It may be a linear or branched alkyl group. In particular, R 1 may be a hydrogen atom, a methyl group or an ethyl group. In particular, R 1may be a hydrogen atom or a methyl group. Even more specifically, R 1 may be a hydrogen atom.

[0037] According to any one of the embodiments of the present invention, m may be 1. In other words, the compound of formula (I) is a tetrahydrofuran derivative.

[0038] According to any one of the embodiments of the present invention, R 2 and R 3 Together, C 1~11 In particular, R may represent an alkanediyl group. 2 and R 3 Together, C 1~11 may represent a linear or branched alkanediyl group of the formula:

[0039] According to any one of the embodiments of the present invention, the cycloether has the formula [ka] [In the formula, n is 0 or 1; Each R 6 , R 7 C optionally containing, separately and independently of each other, a hydrogen atom or one or two functional groups selected from among an ether, ester, carbonyl, amine, amide or alcohol group 1~9 Represents an alkyl group; R 6 and R 7 Together, C 3~10 represents a linear or branched alkanediyl group; and R 8 is a hydrogen atom or C 1~3 represents a straight-chain or branched alkyl group] in the form of any one of its stereoisomers or a mixture thereof.

[0040] According to any one of the embodiments of the present invention, the compound of formula (II) has the following formula: [ka] [In the formula, n is 0 or 1; Each R 6 , R 7 C optionally containing, separately and independently of each other, a hydrogen atom or one or two functional groups selected from among an ether, ester, carbonyl, amine, amide or alcohol group 1~9 Represents an alkyl group; R 6 and R 7 Together, C 3~10 represents a linear or branched alkanediyl group; and R 8 is a hydrogen atom or C 1~3 represents a straight-chain or branched alkyl group] in the form of any one of its stereoisomers or a mixture thereof.

[0041] According to a particular embodiment, compound (III) may be a tricyclic compound and the compound of formula (IV) may be a bicyclic compound. Said compound of formula (IV) may be synthetic or natural.

[0042] According to any one of the embodiments of the present invention, R 6 and R 7 C optionally containing, independently of each other, a hydrogen atom or one or two functional groups selected from among an ether, ester, carbonyl, amine, amide or alcohol group 1~9 may represent an alkyl group, or R 6 and R 7 Together, C 3~9 Represents a linear or branched alkanediyl group. In particular, R 6 and R 7 are each independently a hydrogen atom or an optionally substituted C containing one or two functional groups selected from among an ether, ester, carbonyl, amine, amide or alcohol group; 1~6 may represent an alkyl group, R 6 and R 7 Together, C 3~8 In particular, R may represent a linear or branched alkanediyl group.6 and R 7 are each independently a hydrogen atom or an optionally substituted C containing one or two functional groups selected from among an ether, ester, carbonyl, amine, amide or alcohol group; 1~4 may represent an alkyl group, R 6 and R 7 Together, C 3~8 It may represent a linear or branched alkanediyl group.

[0043] According to any one of the embodiments of the present invention, the above R 6 The group is a hydrogen atom or a C 1~3 In particular, R 6 The group may represent a hydrogen atom or a methyl group. Even more specifically, R 6 The group may represent a hydrogen atom.

[0044] According to any one of the embodiments of the present invention, the above R 7 The group is a hydrogen atom or a C 1~3 In particular, R 7 The group may represent a hydrogen atom or a methyl group. Even more specifically, R 7 The group may represent a hydrogen atom.

[0045] According to any one of the embodiments of the present invention, the above R 6 and R 7 Together, C 3~6 It may represent a linear or branched alkanediyl group, or more preferably a C6 branched alkanediyl group.

[0046] According to any one of the embodiments of the present invention, n may be 1.

[0047] According to any one of the embodiments of the present invention, the cycloether has the formula [ka] [In the formula, R 8has the same meaning as defined above, and each R 9 and R 10 are independent of each other, C 1~3 The compound may be in the form of any one of its stereoisomers or a mixture thereof, wherein R represents a straight-chain or branched alkyl group.

[0048] According to any one of the embodiments of the present invention, the compound of formula (II) has the following formula: [ka] [In the formula, R 8 has the same meaning as defined above, and each R 9 and R 10 are independent of each other, C 1~3 represents a straight-chain or branched alkyl group] in the form of any one of its stereoisomers or a mixture thereof.

[0049] According to any one of the embodiments of the present invention, R 8 is C 1~3 It may be a linear alkyl group. In particular, R 8 may be a methyl or ethyl group. Even more specifically, R 8 may be a methyl group.

[0050] According to any one of the embodiments of the present invention, R 9 may be a methyl or ethyl group. Even more specifically, R 9 may be a methyl group.

[0051] According to any one of the embodiments of the present invention, R 10 may be a methyl or ethyl group. Even more specifically, R 10 may be a methyl group.

[0052] According to a particular embodiment of the present invention, the compound of formula (II) may be 2-(5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol, and the corresponding cycloether of formula (I) may be 3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan, which has four stereocenters and is in the R or S configuration, or a mixture thereof. In other words, the 2-(5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol may be in the form of a substantially pure stereoisomer or a mixture of stereoisomers. According to a particular embodiment of the invention, the compound of formula (II), (IV) or (VI) may be 2-(5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol in the form of a mixture of stereoisomers containing at least 50% of 2-((1SR,4aSR,8aSR)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol. Even more specifically, the compound of formula (II), (IV) or (VI) may be 2-(5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol in the form of a mixture of stereoisomers containing at least 75% of 2-((1SR,4aSR,8aSR)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol. According to a particular embodiment of the present invention, the compound of formula (II), (IV) or (VI) may be 2-((1SR,4aSR,8aSR)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol. For the sake of clarity, the expression "1SR,4aSR,8aRS" refers to an equimolar mixture of 1S,4aS,8aR and 1R,4aR,8aS. According to a particular embodiment of the present invention, the compound of formula (II), (IV) or (VI) may be 2-((1S,4aS,8aS)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol.

[0053] According to a particular embodiment of the invention, the compound of formula (II), (IV) or (VI) may be in the form of a composition comprising at least 50% 2-((1SR,4aSR,8aSR)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol and up to 50% 2-((1SR,4aSR,8aSR)-2,5,5,8a-tetramethyl-1,4,4a,5,6,7,8,8a-octahydronaphthalen-1-yl)ethan-1-ol. In particular, the compound of formula (II), (IV) or (VI) may be in the form of a composition comprising at least 60% 2-((1SR,4aSR,8aSR)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol and at most 40% 2-((1SR,4aSR,8aSR)-2,5,5,8a-tetramethyl-1,4,4a,5,6,7,8,8a-octahydronaphthalen-1-yl)ethan-1-ol. In particular, the compound of formula (II), (IV) or (VI) may be in the form of a composition comprising at least 70% 2-((1SR,4aSR,8aSR)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol and at most 30% 2-((1SR,4aSR,8aSR)-2,5,5,8a-tetramethyl-1,4,4a,5,6,7,8,8a-octahydronaphthalen-1-yl)ethan-1-ol. In particular, the compound of formula (II), (IV) or (VI) may be in the form of a composition comprising at least 80% 2-((1SR,4aSR,8aSR)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol and at most 20% 2-((1SR,4aSR,8aSR)-2,5,5,8a-tetramethyl-1,4,4a,5,6,7,8,8a-octahydronaphthalen-1-yl)ethan-1-ol.In particular, the compound of formula (II), (IV) or (VI) may be in the form of a composition comprising at least 90% 2-((1SR,4aSR,8aSR)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol and at most 10% 2-((1SR,4aSR,8aSR)-2,5,5,8a-tetramethyl-1,4,4a,5,6,7,8,8a-octahydronaphthalen-1-yl)ethan-1-ol. In particular, the compound of formula (II), (IV) or (VI) may be in the form of a composition comprising at least 95% 2-((1SR,4aSR,8aSR)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol and at most 5% 2-((1SR,4aSR,8aSR)-2,5,5,8a-tetramethyl-1,4,4a,5,6,7,8,8a-octahydronaphthalen-1-yl)ethan-1-ol. In particular, the compound of formula (II), (IV) or (VI) may be in the form of a composition comprising at least 98% 2-((1SR,4aSR,8aSR)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol and at most 2% 2-((1SR,4aSR,8aSR)-2,5,5,8a-tetramethyl-1,4,4a,5,6,7,8,8a-octahydronaphthalen-1-yl)ethan-1-ol. In particular, the compound of formula (II), (IV) or (VI) may be in the form of a composition comprising at least 99% 2-((1SR,4aSR,8aSR)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol and at most 1% 2-((1SR,4aSR,8aSR)-2,5,5,8a-tetramethyl-1,4,4a,5,6,7,8,8a-octahydronaphthalen-1-yl)ethan-1-ol.Even more specifically, the compound of formula (II), (IV) or (VI) may be in the form of a composition comprising at least 99.5% 2-((1SR,4aSR,8aSR)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol and at most 0.5% 2-((1SR,4aSR,8aSR)-2,5,5,8a-tetramethyl-1,4,4a,5,6,7,8,8a-octahydronaphthalen-1-yl)ethan-1-ol.

[0054] According to a particular embodiment of the invention, the compound of formula (II), (IV) or (VI) may be in the form of a composition comprising at least 50% 2-((1S,4aS,8aS)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol and up to 50% 2-((1S,4aS,8aS)-2,5,5,8a-tetramethyl-1,4,4a,5,6,7,8,8a-octahydronaphthalen-1-yl)ethan-1-ol. In particular, the compound of formula (II), (IV) or (VI) may be in the form of a composition comprising at least 60% 2-((1S,4aS,8aS)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol and at most 40% 2-((1S,4aS,8aS)-2,5,5,8a-tetramethyl-1,4,4a,5,6,7,8,8a-octahydronaphthalen-1-yl)ethan-1-ol. In particular, the compound of formula (II), (IV) or (VI) may be in the form of a composition comprising at least 70% 2-((1S,4aS,8aS)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol and at most 30% 2-((1S,4aS,8aS)-2,5,5,8a-tetramethyl-1,4,4a,5,6,7,8,8a-octahydronaphthalen-1-yl)ethan-1-ol. In particular, the compound of formula (II), (IV) or (VI) may be in the form of a composition comprising at least 80% 2-((1S,4aS,8aS)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol and at most 20% 2-((1S,4aS,8aS)-2,5,5,8a-tetramethyl-1,4,4a,5,6,7,8,8a-octahydronaphthalen-1-yl)ethan-1-ol. In particular, the compound of formula (II), (IV) or (VI) may be in the form of a composition comprising at least 90% 2-((1S,4aS,8aS)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol and at most 10% 2-((1S,4aS,8aS)-2,5,5,8a-tetramethyl-1,4,4a,5,6,7,8,8a-octahydronaphthalen-1-yl)ethan-1-ol.In particular, the compound of formula (II), (IV) or (VI) may be in the form of a composition comprising at least 95% 2-((1S,4aS,8aS)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol and at most 5% 2-((1S,4aS,8aS)-2,5,5,8a-tetramethyl-1,4,4a,5,6,7,8,8a-octahydronaphthalen-1-yl)ethan-1-ol. In particular, the compound of formula (II), (IV) or (VI) may be in the form of a composition comprising at least 98% 2-((1S,4aS,8aS)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol and at most 2% 2-((1S,4aS,8aS)-2,5,5,8a-tetramethyl-1,4,4a,5,6,7,8,8a-octahydronaphthalen-1-yl)ethan-1-ol. In particular, the compound of formula (II), (IV) or (VI) may be in the form of a composition comprising at least 99% 2-((1S,4aS,8aS)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol and at most 1% 2-((1S,4aS,8aS)-2,5,5,8a-tetramethyl-1,4,4a,5,6,7,8,8a-octahydronaphthalen-1-yl)ethan-1-ol. Even more specifically, the compound of formula (II), (IV) or (VI) may be in the form of a composition comprising at least 99.5% 2-((1S,4aS,8aS)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol and at most 0.5% 2-((1S,4aS,8aS)-2,5,5,8a-tetramethyl-1,4,4a,5,6,7,8,8a-octahydronaphthalen-1-yl)ethan-1-ol.

[0055] According to any embodiment of the present invention, the method of the present invention is stereoselective, i.e., the dehydration cyclization of 2-((1S,4aS,8aS)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol provides (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan.

[0056] According to a particular embodiment of the present invention, the compound of formula (I) may be 3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan in the form of a mixture of stereoisomers containing at least 50% (3aRS,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. Even more specifically, the compound of formula (I) may be 3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan in the form of a mixture of stereoisomers containing at least 75% (3aRS,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. According to a particular embodiment of the present invention, the compound of formula (I) may be (3aRS,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. For clarity, the expression "3aRS,5aSR,9aSR,9bRS" refers to an equimolar mixture of 3aR,5aS,9aS,9bR and 3aS,5aR,9aR,9bS. According to a particular embodiment of the present invention, the compound of formula (I) may be (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan.

[0057] According to a particular embodiment of the present invention, the compound of formula (I) may be in the form of a composition comprising at least 95% (3aRS,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and at most 5% (3aSR,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the compound of formula (I) may be in the form of a composition comprising at least 96% (3aRS,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and at most 4% (3aSR,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the compound of formula (I) may be in the form of a composition comprising at least 97% (3aRS,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and at most 3% (3aSR,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the compound of formula (I) may be in the form of a composition comprising at least 98% (3aRS,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and at most 2% (3aSR,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the compound of formula (I) may be in the form of a composition comprising at least 99% (3aRS,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and at most 1% (3aSR,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the compound of formula (I) may be in the form of a composition comprising at least 99.3% (3aRS,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and at most 0.7% (3aSR,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan.In particular, the compound of formula (I) may be in the form of a composition comprising at least 99.4% (3aRS,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and at most 0.6% (3aSR,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. Even more particularly, the compound of formula (I) may be in the form of a composition comprising at least 99.5% (3aRS,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and at most 0.5% (3aSR,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan.

[0058] According to a particular embodiment of the present invention, the compound of formula (I) may be in the form of a composition comprising at least 95% (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and at most 5% (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the compound of formula (I) may be in the form of a composition comprising at least 96% (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and at most 4% (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the compound of formula (I) may be in the form of a composition comprising at least 97% (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and at most 3% (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the compound of formula (I) may be in the form of a composition comprising at least 98% (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and at most 2% (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the compound of formula (I) may be in the form of a composition comprising at least 99% (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and at most 1% (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the compound of formula (I) may be in the form of a composition comprising at least 99.3% (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and at most 0.7% (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan.In particular, the compound of formula (I) may be in the form of a composition comprising at least 99.4% (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and at most 0.6% (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1]furan. Even more specifically, the compound of formula (I) may be in the form of a composition comprising at least 99.5% (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and at most 0.5% (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan.

[0059] According to a particular embodiment of the invention, the compound of formula (I) may be in the form of a composition comprising 95% to 99.99% of (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and 0.01% to 5% of (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the compound of formula (I) may be in the form of a composition comprising 96% to 99.99% of (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and 0.01% to 4% of (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the compound of formula (I) may be in the form of a composition comprising 97% to 99.99% of (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and 0.01% to 3% of (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the compound of formula (I) may be in the form of a composition comprising 98% to 99.99% of (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and 0.01% to 2% of (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the compound of formula (I) may be in the form of a composition comprising 99% to 99.99% of (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and 0.01% to 1% of (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the compound of formula (I) may be in the form of a composition comprising 99.3% to 99.99% of (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and 0.01% to 0.7% of (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan.In particular, the compound of formula (I) may be in the form of a composition comprising 99.3% to 99.9% of (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and 0.1% to 0.7% of (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the compound of formula (I) may be in the form of a composition comprising 99.4% to 99.9% of (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and 0.1% to 0.6% of (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the compound of formula (I) may be in the form of a composition comprising 99.5% to 99.9% of (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and 0.1% to 0.5% of (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the compound of formula (I) may be in the form of a composition comprising 99.5% to 99.8% of (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and 0.2% to 0.5% of (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan.

[0060] Unless otherwise stated, percentages (%) are meant to indicate percentages by weight of the composition.

[0061] Compounds of formula (II), (IV) and (VI) can be prepared by several methods known in the art, for example, in the case of 2-(5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol, which can be obtained as reported in the Australian Journal of Chemistry, 1989, 497. Compounds of formula (II), (IV) or (VI) may also be produced in vitro by fermentation using purified recombinantly prepared enzymes or using host cells, such as microbial cells, genetically engineered to convert inexpensive carbon sources (such as sugars) to the desired compound of formula (II), (IV) or (VI), or in particular to 2-(5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethyl, in the form of any one of its stereoisomers or a mixture thereof. 2-(5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethyl acetate can be converted to 2-(5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol using chemical or enzymatic conditions known in the art. The advantage of using compounds of formula (II), (IV) or (VI) obtained by fermentation is clear as it allows easy access to starting materials with high enantiomeric excess.

[0062] According to any one of the above embodiments of the method of the invention, said method is further characterized in that it produces a compound of formula (II), (IV) or (VI), in particular 2-((1S,4aS,8aS)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol, by a process comprising a step of contacting farnesyl pyrophosphate with at least one enzyme.

[0063] Another object of the present invention is a composition comprising at least 95% (3aRS,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and at most 5% (3aSR,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the composition of the present invention may comprise at least 96% (3aRS,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and at most 4% (3aSR,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the composition of the present invention may comprise at least 97% (3aRS,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and at most 3% (3aSR,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the composition of the present invention may comprise at least 98% (3aRS,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and at most 2% (3aSR,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the composition of the present invention may contain at least 99% (3aRS,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and at most 1% (3aSR,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the composition of the present invention may contain at least 99.3% (3aRS,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and at most 0.7% (3aSR,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan.In particular, the composition of the present invention may comprise at least 99.4% (3aRS,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and at most 0.6% (3aSR,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. Even more specifically, the composition of the present invention may comprise at least 99.5% (3aRS,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and at most 0.5% (3aSR,5aSR,9aSR,9bRS)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan.

[0064] According to a particular embodiment of the present invention, the composition of the present invention may comprise at least 95% (3aR, 5aS, 9aS, 9bR)-3a, 6, 6, 9a-tetramethyldodecahydronaphtho[2,1-b]furan and at most 5% (3aS, 5aS, 9aS, 9bR)-3a, 6, 6, 9a-tetramethyldodecahydronaphtho[2,1-b]furan.In particular, the composition of the present invention may comprise at least 96% (3aR, 5aS, 9aS, 9bR)-3a, 6, 6, 9a-tetramethyldodecahydronaphtho[2,1-b]furan and at most 4% (3aS, 5aS, 9aS, 9bR)-3a, 6, 6, 9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the composition of the present invention may comprise at least 97% (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and at most 3% (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the composition of the present invention may comprise at least 98% (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and at most 2% (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the composition of the present invention may comprise at least 99% (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and at most 1% (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the composition of the present invention may comprise at least 99.3% (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and at most 0.7% (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan.In particular, the composition of the present invention may comprise at least 99.4% (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and at most 0.6% (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan.More specifically, the composition of the present invention may comprise at least 99.5% (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and at most 0.5% (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan.

[0065] According to a particular embodiment of the present invention, the composition of the present invention may contain 95% to 99.99% (3aR, 5aS, 9aS, 9bR)-3a, 6, 6, 9a-tetramethyldodecahydronaphtho[2,1-b]furan and 0.01% to 5% (3aS, 5aS, 9aS, 9bR)-3a, 6, 6, 9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the composition of the present invention may contain 96% to 99.99% (3aR, 5aS, 9aS, 9bR)-3a, 6, 6, 9a-tetramethyldodecahydronaphtho[2,1-b]furan and 0.01% to 4% (3aS, 5aS, 9aS, 9bR)-3a, 6, 6, 9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the composition of the present invention may contain 97% to 99.99% (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and 0.01% to 3% (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the composition of the present invention may contain 98% to 99.99% (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and 0.01% to 2% (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the composition of the present invention may contain 99% to 99.99% of (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and 0.01% to 1% of (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the composition of the present invention may contain 99.3% to 99.99% of (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and 0.01% to 0.7% of (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan.In particular, the composition of the present invention may contain 99.3% to 99.9% (3aR, 5aS, 9aS, 9bR)-3a, 6, 6, 9a-tetramethyldodecahydronaphtho[2,1-b]furan and 0.1% to 0.7% (3aS, 5aS, 9aS, 9bR)-3a, 6, 6, 9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the composition of the present invention may contain 99.4% to 99.9% (3aR, 5aS, 9aS, 9bR)-3a, 6, 6, 9a-tetramethyldodecahydronaphtho[2,1-b]furan and 0.1% to 0.6% (3aS, 5aS, 9aS, 9bR)-3a, 6, 6, 9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the composition of the present invention may contain 99.5% to 99.9% of (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and 0.1% to 0.5% of (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. In particular, the composition of the present invention may contain 99.5% to 99.8% of (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan and 0.2% to 0.5% of (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan.

[0066] Said composition of the invention may be used as a perfuming ingredient, for example to impart ambery odor notes. Another subject of the invention is therefore the use of said composition of the invention as defined above as a perfuming ingredient. In other words, the invention relates to a method or process for imparting, enhancing, improving or modifying the olfactory properties of a perfuming composition or a perfumed article or surface, comprising adding to said composition or article an effective amount of a composition of the invention, for example imparting its typical notes. It is understood that the final hedonic effect may depend on the exact dosage and on the organoleptic properties of the composition of the invention, but in any case the addition of the composition of the invention will impart its typical feel to the final product in the form of a note, feel or aspect depending on the dosage.

[0067] By "use of the composition of the invention" it is also to be understood herein the use of any composition containing the composition of the invention that can be advantageously used in the perfumery industry.

[0068] Such compositions, which may in fact be advantageously used as perfuming ingredients, are also the subject of the present invention.

[0069] Another subject of the present invention is therefore i) as perfuming ingredient at least the composition of the invention as defined above, ii) at least one component selected from the group consisting of a fragrance carrier and a fragrance base; and iii) optionally at least one perfume adjuvant; A fragrance composition comprising:

[0070] By "perfume carrier" is meant herein a material that is substantially neutral from the perfume point of view, i.e. does not significantly alter the organoleptic properties of the perfuming ingredients. The carrier may be liquid or solid.

[0071] Liquid carriers can include, as non-limiting examples, emulsifying systems, i.e., solvents and surfactant systems, or solvents commonly used in perfumery.A detailed description of the nature and type of solvents commonly used in perfumery cannot be exhaustive.However, as non-limiting examples, they can include solvents such as butylene or propylene glycol, glycerol, dipropylene glycol and its monoethers, 1,2,3-propanetriyl triacetate, dimethyl glutarate, dimethyl adipate, 1,3-diacetyloxypropan-2-yl acetate, diethyl phthalate, isopropyl myristate, Abalyn® (rosin resin, available from Eastman), benzyl benzoate, benzyl alcohol, 2-(2-ethoxyethoxy)-1-ethanol, triethyl citrate or mixtures thereof (these are the most commonly used), and also naturally occurring solvents such as glycerol or various vegetable oils, such as palm oil, sunflower oil or linseed oil. In the case of compositions containing both a perfume carrier and a perfume base, suitable perfume carriers other than those specified above may also be ethanol, water / ethanol mixtures, limonene or other terpenes, isoparaffins such as those known under the trademark Isopar® (manufacturer: Exxon Chemical), or glycol ethers and glycol ether esters such as those known under the trademark Dowanol® (manufacturer: Dow Chemical Company), or hydrogenated castor oil such as those known under the trademark Cremophor® RH 40 (manufacturer: BASF).

[0072] Solid carrier is meant to refer to a material to which the perfume composition or some elements of the perfume composition can be chemically or physically bound.Generally, such solid carriers are used to stabilize the composition or to control the evaporation rate of the composition or some components.Solid carriers are currently used in the art, and the skilled person knows how to achieve the desired effect.However, non-limiting examples of solid carriers can include absorbent gums or polymers or inorganic materials, such as porous polymers, cyclodextrins, dextrins, maltodextrins, wood materials, organic or inorganic gels, clays, gypsum talc or zeolites.

[0073] Other non-limiting examples of solid carriers can include encapsulating materials.Examples of such materials include wall-forming and plasticizing materials, such as glucose syrup, natural or modified starch, hydrocolloids, cellulose derivatives, polyvinyl acetate, polyvinyl alcohol, proteins or pectins, vegetable gums, such as gum arabic (gum arabic), urea, sodium chloride, sodium sulfate, zeolites, sodium carbonate, sodium bicarbonate, clays, talc, calcium carbonate, magnesium sulfate, gypsum, calcium sulfate, magnesium oxide, zinc oxide, titanium dioxide, calcium chloride, potassium chloride, magnesium chloride, zinc chloride, carbohydrates, sugars, such as sucrose, monosaccharides, disaccharides, trisaccharides and polysaccharides and derivatives, such as chitosan, starch, cellulose, carboxymethyl methylcellulose, Methylcellulose, hydroxyethylcellulose, ethylcellulose, propylcellulose, polyols / sugar alcohols such as sorbitol, maltitol, xylitol, erythritol, and isomalt, polyethylene glycols (PEG), polyvinylpyrrolidine (PVP), polyvinyl alcohol, acrylamides, acrylates, polyacrylic acid and related, maleic anhydride copolymers, amine functional polymers, vinyl ethers, styrene, polystyrene sulfonates, vinyl acids, ethylene glycol-propylene glycol block copolymers, vegetable gums, acacia gum, pectin, xanthan, alginates, carrageenan, citric acid or any water-soluble solid acid, fatty alcohols or fatty acids and mixtures thereof, or references such as H. Scherz, Hydrokolloide: Stabilisatoren, Dickungs- und Geliermittel in Lebensmitteln, Band 2 der Schriftenreihe Lebensmittelchemie, Lebensmittelqualitaet, Behr's Verlag GmbH & Co., Hamburg, 1996. Encapsulation is a method well known to those skilled in the art and can be carried out by using techniques such as spray drying, coagulation or even extrusion, or can consist of coating encapsulation, including coacervation and complex coacervation techniques.

[0074] Non-limiting examples of solid carriers include core-shell capsules comprising aminoplast, polyamide, polyester, polyurea or polyurethane type resins or mixtures thereof (all of the above resins are well known to those skilled in the art) using techniques such as phase separation processes induced by polymerization, interfacial polymerization, coacervation or all of these (all of the above techniques are described in the art), optionally in the presence of polymeric stabilizers or cationic copolymers.

[0075] The resins may be prepared by polycondensation of aldehydes (e.g., formaldehyde, 2,2-dimethoxyethanal, glyoxal, glyoxylic acid or glycolaldehyde and mixtures thereof) with amines, such as urea, benzoguanamine, glycolyl, melamine, methylolmelamine, methylated methylolmelamine, guanazole, and mixtures thereof. Alternatively, preformed resin alkylolated polyamines may be used, such as those commercially available under the trademarks Urac® (manufactured by Cytec Technology Corp.), Cymel® (manufactured by Cytec Technology Corp.), Urecoll® or Luracoll® (manufactured by BASF).

[0076] Other resins are produced by polycondensation of polyisocyanates such as the trimer of hexamethylene diisocyanate, the trimer of isophorone diisocyanate or xylylene diisocyanate, or the biuret of hexamethylene diisocyanate, or the trimer of xylylene diisocyanate and trimethylolpropane (known under the trademark Takenate®, manufactured by Mitsui Chemicals), of which the trimer of xylylene diisocyanate and trimethylolpropane and the biuret of hexamethylene diisocyanate are preferred, with polyols such as glycerol.

[0077] Some of the seminal publications on the encapsulation of perfumes by polycondensation of amino resins, i.e. melamine-based resins with aldehydes, include articles such as those published by K. Dietrich et al., Acta Polymerica, vol. 40, pp. 243, 325 and 683, 1989 and vol. 41, pp. 91, 1990. Such articles already describe the various parameters that affect the production of such core-shell microcapsules according to the methods of the prior art, which are further elaborated and exemplified in the patent literature. U.S. Patent No. 4,396,670 by Wiggins Teape Group Limited is a suitable early example of the latter. Since then, many other authors have enriched the literature in this field, and it would be impossible to cover all the developments published here, but a general knowledge of encapsulation techniques is very important. More recent relevant publications disclosing suitable uses of such microcapsules are represented, for example, by the article by K. Bruyninckx and M. Dusserier, ACS Sustainable Chemistry & Engineering, 2019, Vol. 7, pp. 8041-8054.

[0078] As meant herein, a "perfume base" is a composition that includes at least one perfuming co-ingredient.

[0079] The perfuming co-ingredient is not (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan. Moreover, by "perfuming co-ingredient" is meant herein a compound used in a perfuming preparation or composition, which is used for the primary purpose of imparting a hedonic effect, i.e. imparting or modulating an odor. In other words, such co-ingredients to be considered perfuming ingredients must be recognized by those skilled in the art not simply as having an odor, but as being able to impart or modify the odor of a composition in a positive or pleasant way. Perfuming co-ingredients can impart additional benefits beyond modulating or imparting an odor, such as long-lasting, blooming, malodor neutralization, antibacterial effect, antiviral effect, microbial stability, or pest control.

[0080] The nature and type of perfuming co-ingredients present in the base do not warrant a more detailed description here, which are in any case not exhaustive, and the skilled person can select them on the basis of his general knowledge and according to the intended use or application and the desired organoleptic effect. In general terms, these perfuming co-ingredients belong to various chemical classes, such as alcohols, lactones, aldehydes, ketones, esters, ethers, acetates, nitriles, terpenoids, nitrogen- or sulphur-containing heterocyclic compounds and essential oils, and said perfuming co-ingredients may be of natural or synthetic origin.

[0081] In particular, perfuming co-ingredients commonly used in perfume formulations, such as - aldehyde components: decanal, dodecanal, 2-methyl-undecanal, 10-undecenal, octanal, nonanal and / or nonenal, - Aromatic Herbal Ingredients: Eucalyptus Oil, Camphor, Eucalyptol, 5-Methyltricyclo[6.2.1.0~2,7~]undecane-4-one, 1-Methoxy-3-Hexanethiol, 2-Ethyl-4,4-Dimethyl-1,3-Oxathiane, 2,2,7 / 8,9 / 10-Tetramethylspiro[5.5]undec-8-en-1-one, Menthol and / or Alpha-Pinene, - Balsamic ingredients: coumarin, ethyl vanillin and / or vanillin, - Citrus Ingredients: Dihydromyrcenol, Citral, Orange Oil, Linalyl Acetate, Citronellyl Nitrile, Orange Terpenes, Limonene, 1-p-Menthen-8-yl Acetate and / or 1,4(8)-p-Menthadiene, - Floral Ingredients: Methyl Dihydrojasmonate, Linalool, Citronellol, Phenylethanol, 3-(4-tert-butylphenyl)-2-methylpropanal, Hexyl Cinnamaldehyde, Benzyl Acetate, Benzyl Salicylate, Tetrahydro-2-isobutyl-4-methyl-4(2H)-pyranol, Beta-Ionone, Methyl 2-(Methylamino)benzoate, (E)-3-Methyl-4-(2,6,6-trimethyl-2-cyclohexen-1-yl)-3-butene-2- 1-(2,6,6-trimethyl-1,3-cyclohexadien-1-yl)-2-buten-1-one, (2E)-1-(2,6,6-trimethyl-2-cyclohexen-1-yl)-2-buten-1-one, (2E)-1-[2,6,6-trimethyl-3-cyclohexen-1-yl]-2-buten-1-one, (2E)-1-(2,6,6-trimethyl-1-cyclohexen-1-yl)-2-buten-1-one, (2E)-1-(2,6,6-trimethyl-1-cyclohexen-1-yl)- 2-Buten-1-one, 2,5-Dimethyl-2-indanethanol, 2,6,6-Trimethyl-3-cyclohexene-1-carboxylate, 3-(4,4-Dimethyl-1-cyclohexen-1-yl)propanal, 3-(3,3 / 1,1-Dimethyl-5-indanyl)propanal, Hexyl salicylate, 3,7-Dimethyl-1,6-nonadien-3-ol, 3-(4-Isopropylphenyl)-2-methylpropanal, Versyl acetate, Geraniol, p-Menthol-1-en-8- ol, 4-(1,1-dimethylethyl)-1-cyclohexyl acetate, 1,1-dimethyl-2-phenylethyl acetate, 4-cyclohexyl-2-methyl-2-butanol, amyl salicylate, methyl cis-dihydrojasmonate, 3-methyl-5-phenyl-1-pentanol, vergyl propionate, geranyl acetate, tetrahydrolinalool, cis-7-p-menthanol, propyl (S)-2-(1,1-dimethylpropoxy)propanoate, 2-methoxynaphthalene, 2,2,2-Trichloro-1-phenylethyl acetate, 4 / 3-(4-hydroxy-4-methylpentyl)-3-cyclohexene-1-carbaldehyde, amylcinnamaldehyde, 8-decen-5-olide, 4-phenyl-2-butanone, isononyl acetate, 4-(1,1-dimethylethyl)-1-cyclohexyl acetate, vergyl isobutyrate and / or a mixture of methyl ionone isomers, - Fruit ingredients: gamma-undecalactone, 2,2,5-trimethyl-5-pentylcyclopentanone, 2-methyl-4-propyl-1,3-oxathiane, 4-decanolide, ethyl 2-methyl-pentanoate, hexyl acetate, ethyl 2-methylbutyrate, gamma-nonalactone, allyl heptanoate, 2-phenoxyethyl isobutyrate, ethyl 2-methyl-1,3-dioxolane-2-acetate, diethyl 1,4-cyclohexanedicarboxylate, 3-methyl-2-hexen-1-yl acetate, 1-[3,3-dimethylcyclohexyl]ethyl[3-ethyl-2-oxiranyl]acetate and / or diethyl 1,4-cyclohexanedicarboxylate; - Green ingredients: 2-methyl-3-hexanone (E)-oxime, 2,4-dimethyl-3-cyclohexene-1-carbaldehyde, 2-tert-butyl-1-cyclohexyl acetate, styrallyl acetate, allyl (2-methylbutoxy) acetate, 4-methyl-3-decen-5-ol, diphenyl ether, (Z)-3-hexen-1-ol and / or 1-(5,5-dimethyl-1-cyclohexen-1-yl)-4-penten-1-one, - Musk ingredients: 1,4-dioxa-5,17-cycloheptadecanedione, (Z)-4-cyclopentadecen-1-one, 3-methylcyclopentadecanone, 1-oxa-12-cyclohexadecen-2-one, 1-oxa-13-cyclohexadecen-2-one, (9Z)-9-cycloheptadecen-1-one, 2-{(1S)-1-[(1R)-3,3-dimethylcyclohexyl]ethoxy}-2-oxoethylpropionate, 3-methyl-5-cyclo Pentadecen-1-one, 4,6,6,7,8,8-hexamethyl-1,3,4,6,7,8-hexahydrocyclopenta[g]isochromene, (1S,1'R)-2-[1-(3',3'-dimethyl-1'-cyclohexyl)ethoxy]-2-methylpropylpropanoate, oxacyclohexadecan-2-one and / or (1S,1'R)-[1-(3',3'-dimethyl-1'-cyclohexyl)ethoxycarbonyl]methylpropanoate, - Woody Ingredients: 1-[(1RS,6SR)-2,2,6-trimethylcyclohexyl]-3-hexanol, 3,3-dimethyl-5-[(1R)-2,2,3-trimethyl-3-cyclopenten-1-yl]-4-penten-2-ol, 3,4'-dimethylspiro[oxirane-2,9'-tricyclo[6.2.1.0 2,7 ]undec[4]ene, (1-ethoxyethoxy)cyclododecane, 2,2,9,11-tetramethylspiro[5.5]undec-8-en-1-yl acetate, 1-(octahydro-2,3,8,8-tetramethyl-2-naphthalenyl)-1-ethanone, patchouli oil, terpene fraction of patchouli oil, Clearwood® (manufacturer: Firmenich SA), (1'R,E)-2-ethyl-4-(2',2',3'-trimethyl-3'-cyclopenten-1'-yl)-2-buten-1-ol, 2-ethyl-4-(2,2,3-trimethyl-3-cyclopenten-1-yl)-2-buten-1-ol, methyl cedryl ketone, 5-(2,2,3-trimethyl-3-cyclopentenyl)-3-methylpentan-2-ol, 1-(2,3,8,8-tetramethyl-1,2,3,4,6,7,8,8a-octahydronaphthalen-2-yl)ethan-1-one and / or isobornyl acetate, other ingredients (for example amber, powdery spicy or watery): heliotropin, anisaldehyde, eugenol, cinnamic aldehyde, clove oil, 3-(1,3-benzodioxol-5-yl)-2-methylpropanal, 7-methyl-2H-1,5-benzodioxepin-3(4H)-one, 2,5,5-trimethyl-1,2,3,4,4a,5,6,7-octahydro-2-naphthalenol, 1-phenylvinyl acetate, 6-methyl-7-oxa-1-thia-4-azaspiro[4,4]nonane and / or 3-(3-isopropyl-1-phenyl)butanal may be mentioned.

[0082] The perfume base according to the present invention is not limited to the above-mentioned perfuming co-ingredients, many others of which are listed in references such as the book by S. Arctander, Perfume and Flavor Chemicals, 1969, Montclair, New Jersey, USA or its latest edition, or other treatises of a similar nature, as well as the abundant patent literature in the field of perfumery.It is also understood that the above-mentioned co-ingredients may be compounds known to release in a controlled manner various types of perfuming compounds, also known as properfumes or professional fragrances. Non-limiting examples of suitable pro-fragrances include 4-(dodecylthio)-4-(2,6,6-trimethyl-2-cyclohexen-1-yl)-2-butanone, 4-(dodecylthio)-4-(2,6,6-trimethyl-1-cyclohexen-1-yl)-2-butanone, trans-3-(dodecylthio)-1-(2,6,6-trimethyl-3-cyclohexen-1-yl)-1-butanone, 3-(dodecylsulfonyl)-1-(2,6,6-trimethylcyclohex-3-en-1-yl)butan-1-one, linear polysiloxane copolymer of (3-mercaptopropyl)(methyl)dimethoxysilane, 1-[6-ethyl-2,6-dimethyl-3-cyclohexen-1-yl]-2-butanone ... octan-1-one, 2-(dodecylthio)octan-4-one, 2-(dodecylsulfonyl)octan-4-one, 4-oxooctane-2-yl dodecanoate, 2-phenylethyl oxo(phenyl)acetate, 3,7-dimethylocta-2,6-dien-1-yl oxo(phenyl)acetate, (Z)-hex-3-en-1-yl oxo(phenyl)acetate, 3,7-dimethyl-2,6-octadien-1-yl hexadecanoate, bis(3,7-dimethylocta-2,6-dien-1-yl)succinate, (2E,6Z)-2,6-nonadienyl hexadecanoate, (2E,6Z)-2,6-nonadien-1-yl tetradecanoate, (2E,6Z)-2,6-Nonadien-1-yl dodecanoate, (2-((2-methylundec-1-en-1-yl)oxy)ethyl)benzene, 1-methoxy-4-(3-methyl-4-phenethoxybut-3-en-1-yl)benzene, (3-methyl-4-phenethoxybut-3-en-1-yl)benzene, 1-(((Z)-hex-3-en-1-yl)oxy)-2-methylundec-1-ene, (2-((2-methylundec-1-en-1-yl)oxy)ethoxy)benzene, 2-methyl-1-(octan-3-yloxy)undec-1-ene, 1-methyl 1-phenethoxy-4-(1-phenethoxyprop-1-en-2-yl)benzene, 1-methyl-4-(1-phenethoxyprop-1-en-2-yl)benzene, 2-(1-phenethoxyprop-1-en-2-yl)naphthalene, (2-phenethoxyvinyl)benzene, 2-(1-((3,7-dimethyloct-6-en-1-yl)oxy)prop-1-en-2-yl)naphthalene, (2-((2-pentylcyclopentylidene)methoxy)ethyl)benzene, 4-allyl-2-methoxy-1-((2-methoxy-2-phenylvinyl)oxy)benzene , (2-((2-heptylcyclopentylidene)methoxy)ethyl)benzene, 1-methoxy-4-(1-phenethoxyprop-1-en-2-yl)benzene, (2-((2-methyl-4-(2,6,6-trimethylcyclohex-1-en-1-yl)but-1-en-1-yl)oxy)ethyl)benzene, 1-methoxy-4-(2-methyl-3-phenethoxyallyl)benzene, (2-((2-isopropyl-5-methylcyclohexylidene)methoxy)ethyl)benzene, 1-isopropyl-4-methyl-2-((2-pentylcyclopentyl Examples of the cyclopentyl ether include 2-methoxy-1-((2-pentylcyclopentylidene)methoxy)benzene, 2-methoxy-1-((2-pentylcyclopentylidene)methoxy)-4-propylbenzene, 2-ethoxy-1-((2-methoxy-2-phenylvinyl)oxy)-4-methylbenzene, 3-methoxy-4-((2-methoxy-2-phenylvinyl)oxy)benzaldehyde, 1-isopropyl-2-((2-methoxy-2-phenylvinyl)oxy)-4-methylbenzene, 4-((2-(hexyloxy)-2-phenylvinyl)oxy)-3-methoxybenzaldehyde or mixtures thereof.

[0083] By "perfuming adjuvant" is meant herein an ingredient capable of imparting additional added benefits such as color, specific light resistance, chemical stability, etc. A detailed description of the nature and type of adjuvants commonly used in perfumed compositions cannot be exhaustive, but it should be mentioned that said ingredients are well known to those skilled in the art. Specific non-limiting examples may include: viscosity agents (e.g. surfactants, thickeners, gelling agents and / or rheology modifiers), stabilizers (e.g. preservatives, antioxidants, heat / light and / or buffers or chelating agents, e.g. BHT), colorants (e.g. dyes and / or pigments), preservatives (e.g. antibacterial or bactericidal or antifungal or anti-irritant), abrasives, skin cooling agents, fixatives, insect repellents, ointments, vitamins and mixtures thereof. By "fixatives", also called "modifiers", is understood herein an agent capable of influencing the way in which the odor of a composition incorporating said modifier, in particular the evaporation rate and intensity, can be perceived by an observer or its user over time, compared to the same perception in the absence of the modifier. In particular, said modifiers make it possible to extend the time for which their fragrance is perceived.Non-limiting examples of suitable modifiers include methyl glucoside polyol, ethyl glucoside polyol, propyl glucoside polyol, isocetyl alcohol, PPG-3 myristyl ether, neopentyl glycol diethylhexanoate, sucrose laurate, sucrose dilaurate, sucrose myristate, sucrose palmitate, sucrose stearate, sucrose distearate, sucrose tristearate, hyaluronic acid disaccharide sodium salt, sodium hyaluronate, propylene glycol propyl ether; dicetyl ether; polyglycerin-4 ether. ;Isoceteth-5;Isoceteth-7, Isoceteth-10;Isoceteth-12;Isoceteth-15;Isoceteth-20;Isoceteth-25;Isoceteth-30;Disodium lauroamphodipropionate;Hexaethylene glycol monododecyl ether;And mixtures thereof;Neopentyl glycol diisononanoate;Cetearyl ethylhexanoate;Panthenol ethyl ether, DL-panthenol, N-hexadecyl n-nonanoate, n-octadecyl n-nonanoate, Profragrance, cyclodextrin, encapsulation, and combinations thereof. Up to 20% by weight of the modifier, based on the total weight of the perfume composition, may be incorporated into the perfumed consumer product.

[0084] It is understood that a person skilled in the art is perfectly capable of designing the optimum formulation for the desired effect by mixing the above-mentioned components of the perfuming composition not only by applying standard knowledge in the art but also by trial and error method.

[0085] The composition of the present invention, which comprises the composition of the present invention and at least one perfume carrier, comprises a particular embodiment of the present invention, as well as a perfumed composition comprising the composition of the present invention, at least one perfume carrier, at least one perfume base, and optionally at least one perfume adjuvant.

[0086] For the sake of clarity, it is also understood that any mixture obtained directly from a chemical synthesis, such as a reaction medium without appropriate purification, which may contain the composition of the invention as a starting, intermediate or final product, cannot be considered a perfuming composition according to the invention, unless said mixture provides the composition of the invention in a form suitable for perfumery.Unless otherwise stated, unpurified reaction mixtures are generally excluded from the present invention.

[0087] The compositions of the invention may also be used advantageously in all areas of modern perfumery, i.e. perfumes or functional perfumery, to actively impart or modify the odor of consumer products to which said compositions of the invention are added. Another subject of the invention therefore consists of perfumed consumer products comprising, as perfuming ingredient, a composition of the invention as defined above.

[0088] The composition of the present invention may be added as such or as part of a perfuming composition of the present invention.

[0089] For the sake of clarity, "perfumed consumer product" is meant to refer to a consumer product that provides at least a pleasant fragrance effect to the surface or space to which it is applied (e.g., skin, hair, textile, or household surface).In other words, the perfumed consumer product according to the present invention is a perfumed consumer product that comprises a functional formulation, and optionally additional benefit agents corresponding to the desired consumer product, and an olfactory effective amount of at least one compound of the present invention.For the sake of clarity, the perfumed consumer product is a non-edible product.

[0090] The nature and type of ingredients of the perfumed consumer products do not warrant a more detailed description here (which would in any case not be exhaustive), and the skilled person can select them on the basis of his general knowledge and according to the nature and desired effect of said product.

[0091] Non-limiting examples of suitable perfumed consumer products include fragrances, such as fine perfumes, splashes or eau de parfums, colognes or shave or aftershave lotions, fabric care products, such as liquid or solid detergents (optionally in pod or tablet form), fabric softeners, liquid or solid fragrance enhancers, dryer sheets, fabric refreshers, ironing water, paper, bleach, carpet cleaners, curtain care products; body care products, such as hair care products (e.g. shampoos, leave-on or rinse-off hair conditioners, coloring preparations or hairsprays, color care products, hair shaping products, dental care products), disinfectants, intimate care products; cosmetic preparations (e.g. skin creams or lotions, vanishing creams or deodorants or or antiperspirants (e.g. sprays or roll-ons), hair removers, tanning or anti-sun or after-sun products, nail products, skin cleansers, make-up); or skin care products (e.g. soaps, shower or bath smoothes, oils or gels, or hygiene products or foot / hand care products); air care products, such as air fresheners or "ready to use" powdered air fresheners that may be used in domestic spaces (rooms, refrigerators, cupboards, shoes or cars) and / or public spaces (hall, hotel, shopping mall, etc.); or home care products, such as mould removers, furniture care products, wipes, dishwashing detergents or hard surface (e.g. floor, bath, sanitary or window cleaning) detergents; leather care products; car care products, such as polishes, waxes or plastic cleaners.

[0092] Some of the above mentioned perfumed consumer products may be aggressive media for the compositions of the invention, and it may be necessary to protect the latter from premature degradation, for example by encapsulation or by chemically binding with another suitable chemical, which is suitable for releasing the compositions of the invention upon a suitable external stimulus, such as an enzyme, light, heat or a change in pH.

[0093] Exemplary methods for carrying out the methods of the present invention are reported in the Examples hereinafter. EXAMPLES

[0094] The invention will now be described in further detail by the following examples, in which abbreviations have their usual meaning in the art and temperatures are given in degrees Celsius (° C.). Gas chromatography was prepared on an Agilent 7890 A series equipped with a HP5 column (30 m×0.25 mm ID, 0.25 μm film) and tetradecane was used as the internal standard.

[0095] [Example 1] (Typical Experimental Procedure for Preactivation of Zeolite Catalysts) In the case of zeolite, preactivation before testing was performed by heating 10 g of the raw material at 10 °C for 10 min. -1 The preactivation by calcination was systematically applied to all the zeolites for comparison, since this step is essential to convert the ammonium forms of the samples to their proton forms.

[0096] [Example 2] (Preparation of (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan by cyclization of 2-((1S,4aS,8aS)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol) 2-((1S,4aS,8aS)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol (compound of formula (II), 5 g, 21.16 mmol) and toluene (95 g, 1.03 mol) were charged to a 100 ml round bottom flask and heated to 40° C. with mechanical stirring. Once the desired reaction temperature was reached, 250 mg (5 wt % with respect to starting material) of a solid acid catalyst comprising either an acid treated clay, an acid zeolite or an acid resin was added and the mixture was left with stirring for up to 22 hours. Table I shows the desired (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan (compound of formula (I)), its isomer (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan (corresponding to compound A) and the starting isomer 2-[(1S,4aS,8aS)- The yields of 2,5,5,8a-tetramethyl-1,4,4a,5,6,7,8,8a-octahydro-1-naphthalenyl]ethanol and 2-((4aS,8aS)-2,5,5,8a-tetramethyl-3,4,4a,5,6,7,8,8a-octahydronaphthalen-1-yl)ethan-1-ol (corresponding to compound of formula (II') and compound B, respectively) were reported. [Table 1-1] [Table 1-2]

[0097] The process of the invention makes it possible to obtain the compound of formula (I) very selectively with little or no formation of undesired compounds such as (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan (compound A), 2-[(1S,4aS,8aS)-2,5,5,8a-tetramethyl-1,4,4a,5,6,7,8,8a-octahydro-1-naphthalenyl]ethanol (compound of formula (II')) and 2-((4aS,8aS)-2,5,5,8a-tetramethyl-3,4,4a,5,6,7,8,8a-octahydronaphthalen-1-yl)ethan-1-ol (compound B). The cyclization of the compound of formula (II) in the presence of homogeneous catalysts reported in the prior art (Table 1, entries 15 and 16) affords higher amounts of isomerization products, i.e., the compound of formula (II') and compound B, whereas the cyclization of compound B (Table 1, entry 17) or of the compound of formula (II') (Table 1, entry 19) in the presence of heterogeneous catalysts affords no compound of formula (I) or only traces of the compound of formula (I).

[0098] [Example 3] (Preparation of (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan by cyclization of 2-((1S,4aS,8aS)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol using different solvents) Experiment 2 was repeated using CBV780 but using different solvents as summarized in Table 2. [Table 2]

[0099] [Example 4] (Preparation of (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan by cyclization of 2-((1S,4aS,8aS)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol) 50 g of 2-((1S,4aS,8aS)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol, 450 g of toluene were charged to a reactor and heated to 40° C. Once the desired temperature was reached, 2.5 g of CBV780 was added and the reaction was left with stirring for 12 hours to give the desired (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan product with 97.7 GC%.

[0100] [Example 5] (Cyclization of 22-((1S,4aS,8aS)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol to prepare (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan) 50 g of 2-((1S,4aS,8aS)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol, 115 g of toluene were charged to a reactor and heated to 50° C. Once the desired temperature was reached, 2.5 g of CBV780 was added and the reaction was left with stirring for 12 hours to give the desired (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan product with 94.3 GC%.

[0101] [Example 6] (Preparation of (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan by cyclization of 2-((1S,4aS,8aS)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol) 50 g of 2-((1S,4aS,8aS)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)ethan-1-ol, 200 g of toluene were charged to a reactor and heated to 50° C. Once the desired temperature was reached, 2.5 g of F-24X was added and the reaction was left with stirring for 12 hours to give the desired (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan product with 88 GC%.

Claims

1. The following formula (I) 【Chemistry 1】 [Wherein m is 1 or 2; R １ is a hydrogen atom or C １～３ represents an alkyl group; Each R ２ , R ３ , R ４ C optionally containing, separately and independently of one another, a hydrogen atom or one or two functional groups selected from among an ether, ester, carbonyl, amine, amide or alcohol group; １～１８ represents an alkyl group; R １ and R ２ C optionally containing one or two functional groups selected from among ether, ester, carbonyl, amine, amide or alcohol groups; ２～１１ represents an alkanediyl group, and / or R ２ and R ３ Together, C １～１１ represents an alkanediyl group, and / or R ３ and R ４ Together, C ４～９ represents an alkanediyl group, and / or R １ and R ４ Together, C ２～９ represents an alkanediyl group; R ５ is a hydrogen atom or C １～３ represents an alkyl group] in the form of any one of its stereoisomers or a mixture thereof, comprising the steps of: 【Chemistry 2】 [In the formula, m, R １ , R ２ , R ３ , R ４ and R ５ has the same meaning as defined above] in the form of any one of its stereoisomers or a mixture thereof in the presence of a heterogeneous acidic catalyst.

2. The method of claim 1 , wherein the heterogeneous acidic catalyst is crystalline or amorphous.

3. 3. The method of claim 1 or 2, wherein the heterogeneous acidic catalyst comprises silicon, tin, zirconium, hafnium or titanium and a second metal selected from the group consisting of aluminum, boron, iron or mixtures thereof.

4. 3. The process of claim 1 or 2, wherein the heterogeneous acidic catalyst is an aluminosilicate catalyst.

5. 5. The process of claim 4, wherein the aluminosilicate catalyst is a zeolite or a clay.

6. The method of claim 5, wherein the clay is an acid treated clay.

7. 6. The method of claim 5, wherein the zeolite is a large pore zeolite.

8. 8. The method of claim 7, wherein the zeolite has a FAU, BEA or MOR topology.

9. The method of claim 7, wherein the silicon:aluminum ratio is in the range between 2.5:1 and 300:

1.

10. R １ The method according to claim 1 or 2, wherein is a hydrogen atom and m is 1.

11. The cycloether has the formula: 【Chemistry 3】 [Wherein, n is 0 or 1; Each R ６ , R ７ C optionally containing, separately and independently of one another, a hydrogen atom or one or two functional groups selected from among an ether, ester, carbonyl, amine, amide or alcohol group; １～９ represents an alkyl group; R ６ and R ７ Together, C ３～１０ represents a linear or branched alkanediyl group; and R ８ is a hydrogen atom or C １～３ 3. The method according to claim 1 or 2, wherein the compound is in the form of any one of its stereoisomers or a mixture thereof, wherein the alkyl group is a straight-chain or branched alkyl group.

12. The compound of formula (II) is represented by the following formula: 【Chemistry 4】 [Wherein, n is 0 or 1; Each R ６ and R ７ C optionally containing, separately and independently of one another, a hydrogen atom or one or two functional groups selected from among an ether, ester, carbonyl, amine, amide or alcohol group; １～９ represents an alkyl group; R ６ and R ７ Together, C ３～１０ represents a linear or branched alkanediyl group; and R ８ is a hydrogen atom or C １～３ 3. The method according to claim 1 or 2, wherein the compound is in the form of any one of its stereoisomers or a mixture thereof, wherein the alkyl group is a straight-chain or branched alkyl group.

13. The cycloether has the formula: 【Chemistry 5】 [In the formula, R ８ has the same meaning as defined above, and each R ９ and R １０ are, independently of each other, C １～３ 3. The method according to claim 1 or 2, wherein the compound is in the form of any one of its stereoisomers or a mixture thereof, wherein the alkyl group is a straight-chain or branched alkyl group.

14. The compound of formula (IV) is represented by the following formula: 【Chemistry 6】 [In the formula, R ８ has the same meaning as defined above, and each R ９ and R １０ are, independently of each other, C １～３ 13. The method according to claim 12, wherein the compound is in the form of any one of its stereoisomers or a mixture thereof, wherein R represents a linear or branched alkyl group.

15. 3. The method of claim 1 or 2, wherein the compound of formula (II) is prepared by a process comprising the step of contacting farnesyl pyrophosphate with at least one enzyme.

16. c) at least 95% (3aR,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan; d) up to 5% of (3aS,5aS,9aS,9bR)-3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan wherein the percentages are based on the total weight of the composition.

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