PROCESS FOR PREPARING DIENE

Abstract

The present invention relates to the field of organic synthesis and more specifically to a process for preparing a compound of formula (I) catalyzed by a nickel complex. The compound of formula (II) is also part of the invention.

Description

The present invention relates to the field of organic synthesis and more specifically to a process for preparing a compound of formula (I) catalyzed by a nickel complex. The compound of formula (II) is also part of the invention. Background of the Invention The 1,3,5-triene or 1,3-diene-5-yne derivatives of formula (I) represent highly desirable skeletons that could be used as such or as key intermediates, useful for preparing more complex compounds in various fields, including perfumery, cosmetics, pharmaceuticals, and agrochemicals. In particular, 1,3-undecadien-5-yne or 1,3,5-undecatriene are valuable compounds known as fragrance ingredients that impart a green note highly prized by perfumers. However, compounds of formula (I) are mainly obtained via Grignard reactions, which are difficult to implement in production due to the high dilution in hazardous solvents and the generation of a significant amount of unwanted waste, particularly halogenated waste. For decades, metal-catalyzed couplings have been widely developed to overcome this drawback. Ref. 341331 above, for example, to obtain triene building blocks as in US4652692 or enyne building blocks. However, metal-catalyzed couplings involving a triple bond require pre-activation of the triple bond, for example, by tin, silyl, or carboxylic acid functional groups. Coupling at the terminal triple bond has never been reported. Therefore, there is still a need to develop a safer and cleaner approach to accessing these compounds through the coupling of a terminal triple bond. The present invention enables the production of compounds of formula (I) in high yield, limiting or even preventing the formation of the (3Z) isomers, by combining two steps, both catalyzed by a nickel complex. To the best of our knowledge, these two steps have never been reported in the prior art. Summary of the Invention The invention relates to a novel process that allows the preparation of the compound of formula (I) using methodologies never reported or suggested in the prior art. Thus, a first object of the present invention is a process for the preparation of a compound of formula (I) R2R4 R3reno Ln / zznz / E / YiAi in a form of any of its stereoisomers or a mixture thereof and wherein the dotted line is a carbon-carbon double bond or a carbon-carbon triple bond; R1 represents a Ciio hydrocarbon group, optionally comprising one or more hydroxy, C1-15 alkoxy, C2-15 alkenyloxy, C3-15 heterocycloalkyl, Ce-io aryloxy and / or C1-4 carboxylic ester groups and R2, R3, R4 and R5, independently of each other, represent a hydrogen atom, a Ci-3 alkyl group or a phenyl group; comprising the reaction of a compound of formula (II) reno Ln / zznz / E / YiAi in a form of any of its stereoisomers and wherein the dotted line, R1, R2, R3, R4 and R5 have the same meaning defined in formula (I) and X represents an OR6 group, an OC(=O)R6 group, an OC(=O)OR6 group or an OSO2R6 group, wherein R6 is a hydrogen atom or a C1-4 alkyl group or a phenyl group; with a nickel catalyst. A second object of the present invention is a process for the preparation of a compound of formula (IV) reno Ln / zznz / E / YiAi (IV) in a form of any of its stereoisomers and wherein R1 represents a Ci-io hydrocarbon group, optionally substituted with one or more hydroxy, Ci-i5 alkoxy, C2-15 alkenyloxy, C3-15 heterocycloalkyl, Ce-io aryloxy and / or C1-4 carboxylic ester groups; R2, R3 and R4, independently of each other, represent a hydrogen atom, a C1-3 alkyl group or a phenyl group and Y is a hydrogen atom, a C1-3 alkyl group or a CHR5X group wherein R5 is a hydrogen atom, a C1-3 alkyl group or a phenyl group and X represents an OR6 group, an OC(=O)R6 group, an OC(=O)OR6 group or an OSO2R6 group, wherein R6 is a hydrogen atom or a C1-4 alkyl group or a phenyl group; reacting together a compound of formula in a form of any of its stereoisomers and wherein R1 has the same meaning as defined in formula (IV); with a compound with the formula reindeer ίη / ζζηζ / Ε / γίΛΐ (VI) in a form of any of its stereoisomers and wherein X, Y, R2, R3 and R4, independently of each other, have the same meaning as defined in formula (IV); in the presence of a nickel catalyst. A third object of the present invention is a compound of formula in any form of its stereoisomers and wherein the dotted line is a carbon-carbon double bond or a carbon-carbon triple bond; R1 represents a linear or branched Ci-io alkyl group, optionally substituted with one or more hydroxy, C1-15 alkoxy, C2-15 alkenyloxy, C3-15 heterocycloalkyl, Ce-io aryloxy and / or Ci4 carboxylic ester groups; R2, R3, R4 and R5, independently of each other, represent a hydrogen atom, a C1-3 alkyl group or a phenyl group and X represents an OR6 group, an OC(=O)R6 group, an OC(=O)OR6 group or an OSO2R6 group, wherein R6 is a hydrogen atom or a C1-4 alkyl group or a phenyl group. Detailed Description of the Invention Surprisingly, it has now been discovered that the compound of formula (I) can be advantageously produced by a Ni-catalyzed coupling reaction followed by a Ni-catalyzed elimination reaction. These unprecedented steps allow the generation of compounds of formula (I) where the double bond at position 3 is primarily E, avoiding the use of strong bases and the generation of halogenated residues. Therefore, a first object of the present invention is a process for the preparation of a compound of formula (I) reno Ln / zznz / E / YiAi in a form of any of its stereoisomers or a mixture thereof and wherein the dotted line is a carbon-carbon double bond or a carbon-carbon triple bond and R1 represents a Ci-io hydrocarbon group, optionally comprising one or more hydroxy, C1-15 alkoxy, C2-15 alkenyloxy, C3-is heterocycloalkyl, Cg-io aryloxy and / or C1-4 carboxylic ester groups and R2, R3, R4 and R5, independently of each other, represent a hydrogen atom, a C1-3 alkyl group or a phenyl group; comprising the reaction of a compound of formula (II) reno Ln / zznz / E / YiAi in a form of any of its stereoisomers and wherein the dotted line, R1, R2, R3, R4 and R5 have the same meaning defined in formula (I) and X represents an OR6 group, an OC(=O)R6 group, an OC(=O)OR6 group or an OSO2R6 group, wherein R6 is a hydrogen atom or a C1-4 alkyl group or a phenyl group; with a nickel catalyst.For the sake of clarity, the expression "any of its stereoisomers or a mixture thereof, or similar," is understood in the normal sense understood by a person skilled in the art, that is, that the compounds cited in the invention may be a pure enantiomer or a mixture of enantiomers. In other words, the compounds cited in the invention may possess at least one stereocenter that may have two different stereochemistries (e.g., R or S); for example, the R1 group may comprise at least one stereocenter. The compounds may even be in the form of a pure enantiomer or in the form of a mixture of enantiomers. The compounds cited in the invention may even be in the form of a pure diastereomer or in the form of a mixture of diastereomers when the compounds possess more than one stereocenter. The compounds may be in racemic or scalematic form.Therefore, compounds can be a stereoisomer or in the form of a composition of matter comprising, or consisting of, several stereoisomers. The wavy line indicates that the double bond may be in the form of its E or Z isomer or a mixture thereof; for example, the invention comprises compositions of matter consisting of one or more compounds of formula (I), having the same chemical structure, but differing in the configuration of the double bond. According to any of the preceding embodiments of the invention, the compound of formula (I) may be in the form of its E or Z isomer or a mixture thereof; for example, the invention comprises compositions of matter consisting of one or more compounds of formula (I), having the same chemical structure but differing in the configuration of the double bond. According to a particular embodiment of the invention, the compound (I) may be in the form of a mixture formed by the 3E and 3Z isomers, wherein the 3E isomers represent at least 50% of the total mixture, or at least 75%, or even at least 90% (i.e., an E / Z mixture comprising between 90 / 10 and 100 / 0).According to another particular embodiment of the invention, the compound (I) can be presented in the form of a mixture formed by the isomers (3E,5Z) and (3Z,5Z) and wherein the isomers (3E,5Z) represent at least 50% of the total mixture, or even at least 75%, or even at least 90% (i.e., an E / Z mixture between 90 / 10 and 100 / 0). For the sake of clarity, the expression where the dotted line is a carbon-carbon double bond or a carbon-carbon triple bond, or the like, has the normal meaning understood by a person skilled in the art, that is, that the entire bond (solid and dashed line) between the carbon atoms connected by the dashed line is a carbon-carbon double bond or a carbon-carbon triple bond. The term "hydrocarbon group" means that such a group is formed from hydrogen and carbon atoms and may be in the form of an aliphatic hydrocarbon, i.e., a linear or branched saturated hydrocarbon (e.g., an alkyl group), or a branched unsaturated hydrocarbon (e.g., an alkenyl or alkynyl group), a saturated cyclic hydrocarbon (e.g., a cycloalkyl group) or an unsaturated cyclic hydrocarbon (e.g., a cycloalkenyl or cycloalkynyl group), or it may be in the form of an aromatic hydrocarbon, i.e., an aryl group, or it may also be in the form of a mixture of groups, e.g., a specific group may comprise a linear alkyl, a branched alkenyl (e.g., having one or more carbon-carbon double bonds), a (poly)cycloalkyl, and an aryl moiety, unless a specific limitation to a single type is mentioned.Similarly, in all embodiments of the invention, when a group is referred to as having more than one type of topology (e.g., linear, cyclic, or branched) and / or being saturated or unsaturated (e.g., alkyl, aromatic, or alkenyl), it also means a group that may comprise residues having any of the topologies or that are saturated or unsaturated, as explained above. Likewise, in all embodiments of the invention, when a group is referred to as having a type of saturation or unsaturation (e.g., alkyl), it is understood that the group may have any type of topology (e.g., linear, cyclic, or branched) or that it may have several residues with various topologies. The term "optionally" is understood to mean that a group may or may not comprise a particular functional group. The term "one or more" is understood to comprise 1 to 7, preferably 1 to 5, and most preferably 1 to 3 functional groups. According to any embodiment of the invention, R1 may be a Ci-io hydrocarbon group, optionally comprising one or more hydroxy, C1-5 alkoxy, C2-5 alkenyloxy, C3-6 heterocycloalkyl, Cg-io aryloxy, and / or carboxylic ester groups. In particular, R1 may be a linear C1-10 alkyl or C2-10 alkenyl group, optionally comprising a hydroxy or C1-4 carboxylic ester group. In particular, R1 may be a linear C1-10 alkyl group, a linear C2-10 alkenyl group, a branched C3-10 alkyl or alkenyl group, a cyclic Cs-io alkyl or alkenyl group, or a Cg-io aryl group, optionally comprising a hydroxy or C1-4 carboxylic ester group. In particular, R1 can be a linear C1-10 alkyl group, a linear C2-10 alkenyl group, a branched C3-10 alkyl or alkenyl group, or a Cg10 aryl group, optionally comprising a C1-4 carboxylic ester or hydroxyl group.Specifically, R1 can be a linear C1-10 alkyl group, a branched C3-10 alkyl group, or a Cg10 aryl group. Specifically, R1 can be a linear C1-10 alkyl group, a branched C3-10 alkyl group, or a phenyl group. Specifically, R1 can be a linear C4-8 alkyl group. Even more specifically, R1 can be a pentyl group. According to any embodiment of the invention, R2, R3, R4, and R5, independently of each other, can be a hydrogen atom or a Ci-3 alkyl group. In particular, R2, R3, R4, and R5, independently of each other, can be a hydrogen atom or a methyl or ethyl group. In particular, R2, R3, R4, and R5, independently of each other, can be a hydrogen atom or a methyl group. In particular, two groups among R2, R3, R4, and R5, independently of each other, can be a hydrogen atom or a methyl group, and the others are hydrogen atoms. In particular, one group among R2, R3, R4, and R5, independently of each other, can be a hydrogen atom or a methyl group, and the others are hydrogen atoms. Even more particularly, R2, R3, R4, and R5 can be hydrogen atoms. According to any embodiment of the invention, R6 can be a C1-3 alkyl group. In particular, R6 can be a methyl or ethyl group. Even more particularly, R6 can be a methyl group. According to any embodiment of the invention, X may represent an OC(=O)R6 group where R6 is a hydrogen atom, a C1-4 alkyl group, or a phenyl group. In particular, X represents an OC(=O)R6 group where R6 is a C1-3 alkyl group. Even more particularly, X represents an acetate group. The terms alkyl, alkoxy, and alkenyl are understood to include branched and linear alkyl and alkenyl groups. The terms alkenyl and alkenyloxy are understood to include one, two, or three olefinic double bonds, preferably one or two olefinic double bonds. The term heterocycloalkyl is understood to include a monocyclic or fused, spiro and / or bicyclic or tricyclic bridged heterocycloalkyl group, preferably monocyclic heterocycloalkyl groups. The term heterocycloalkyl is understood to mean a cycloalkyl group comprising one or more heteroatoms, in particular comprising one or two oxygen atoms. The term aryl or aryloxy is understood to include any group comprising at least one aromatic group such as the phenyl, indenyl, indanyl, benzodioxolyl, dihydrobenzodioxynyl, tetrahydronaphthalenyl or naphthalenyl group. According to a particular embodiment of the invention, the dotted line is a triple bond. In other words, the compound of formula (I) is a compound of formula reno ίη / ζζηζ / Ε / γίΛΐ in a form of any of its stereoisomers or a mixture thereof, wherein R1, R2, R3, R4 and R5 have the same meaning as defined above. And, the compound of formula (II) is of formula R2R4Rl----(Go) R3R5 in a form of any of its stereoisomers and wherein R1, R2, R3, R4, R5 and X have the same meaning defined above. According to a particular embodiment of the invention, the dotted line is a double bond. In other words, the compound of formula (I) is of formula in the form of any of its stereoisomers or a mixture thereof, wherein R1, R2, R3, R4, and R5 have the same meaning as defined above. And, the compound of formula (II) is of formula R2R4(M) R3R5 in any of its stereoisomer forms, wherein R1, R2, R3, R4, R5, and X have the same meanings as defined above. The compound of formula (II'') is obtained by reduction of the compound of formula (II''). According to any embodiment of the invention, the reduction is a hydrogenation. In particular, the hydrogenation can be carried out in the presence of a heterogeneous catalyst such as palladium (Pd°) in its elemental metallic form. In particular, the palladium can be supported on a support material. For clarity, a support material is understood to be a material on which the metal can be deposited and which is inert to the hydrogen source and the substrate. Supported palladium (Pd°) compounds are known and commercially available.A person skilled in the art is able to select the form in which the material is deposited onto the support, such as the metal-to-support material ratio, the form (powder, granules, pellets, extrusions, foams, etc.), and the surface area of ​​the support. Specifically, hydrogenation can be carried out with a heterogeneous catalyst that favors the formation of the Z double bond. In particular, the heterogeneous catalyst is a Lindlar catalyst. Hydrogenation can be performed under conditions known to the person skilled in the art, who can determine the optimal conditions for converting the compound of formula (II7) into the compound of formula (II7 7). The limited examples of suitable compounds of formula (I) may include 1,3-undecadien-5-ino, (3E)-1,3undecadien-5-ino, 1,3,5-undecatrieno, (3E,5Z)-1,3,5undecatrieno, (hexa-3,5-dien-l-in-l-yl)benceno, ((1Z,3E)-hexa1,3,5-trien-1-yl)benceno, ethyl nona-6,8-dien-4-inoato, (4Z,6E)-nona-4,6,8-ethyl trienoate, (2E)-3-methylnona-2,6,8 trien-4-in-l-ol, (2E,4Z,6E)-3-methylnona-2,4,6,8-tetraen-l-ol, 2-methylocta-5,7-dien-3-in-2-ol, (3Z,5E)-2-methylocta-3,5,7trien-2-ol, octa-5,7-dien-3-in-l-ol y (3Z,5E)-octa-3,5,7trien-l-ol. Los ejemplos no limitantes de compuestos adecuados de fórmula (II) pueden incluir acetato de undec-2-en-5-in-l-ilo, acetato de (E)-undec-2-en-5-in-l-ilo, acetato de undeca-2,5dien-l-ilo, acetato de (2E,5Z)-undeca-2,5-dien-l-ilo, acetato de (E)-6-fenilhex-2-en-5-in-l-ilo, acetato de (2E,5Z)-6fenilhexa-2,5-dien-l-ilo, (E)-9-acetoxinon-7-en-4-inoato de etilo, (4Z,7E)-9-acetoxinon-4,7-dienoato de etilo, (2E,7E)-9hidroxi-7-metilnona-2,7-dien-5-in-l-ilo, acetato de (2E,5Z,7E)-9-hidroxi-7-metilnona-2,5,7-trien-l-ilo, acetato de (E)-7-hidroxi-7-metiloct-2-en-5-in-l-ilo, acetato de (2E,5Z)7-hidroxi-7-metilocta-2,5-dien-l-ilo, acetato de (E)-8hidroxioct-2-en-5-in-l-ilo y acetato de (2E,5Z)-8-hidroxiocta2,5-dien-l-ilo. According to any method of the invention, the nickel catalyst follows the formula [Ni(P)4] (III) or [Ni(PP)2] (III') ...or [Ni (P)2ML] (III'') or [Ni(PP)ML] (III''') wherein each P represents, independently of each other, a C3-C30 monodentate ligand in which the coordination groups are one phosphorus atom and each PP represents, independently of each other, a C5-C50 bidentate ligand in which the coordination groups are two phosphorus atoms; and M and L, independently of each other, are an anionic or neutral ligand, with the condition that when M is a neutral ligand, L is a neutral ligand and when M is an anionic ligand, L is an anionic ligand. Non-limiting examples of suitable anionic ligands may include a halogen atom such as Cl, Br, or I. Non-limiting examples of suitable neutral ligands may include compounds containing diphenyls such as acrylonitrile, or ML may be a diene such as cycloocta-1,5-diene. According to any embodiment of the invention, the nickel catalyst has the formula [Ni(P)4] (III) or [Ni(PP)2] (III') where each P represents, independently of each other, a C3-C30 monodentate ligand where the coordination groups are one phosphorus atom and each PP represents, independently of each other, a C5-C50 bidentate ligand where the coordination groups are two phosphorus atoms. According to any embodiment of the invention, the phosphorus atom may be in the form of a phosphine or phosphite group. According to any embodiment of the invention, the ligand (PP) can be selected from the group consisting of 1,2-bis(diphenylphosphino)ethane and 1,4-bis(diphenylphosphino)butane. According to any embodiment of the invention, ligand P may be a C3-C30 monodentate monophosphine ligand or a monodentate monophosphite ligand. In particular, ligand P may represent a monophosphite of formula P(OR7)3 or a monophosphine of formula PR73, wherein R7 is a C1-C10 group, such as a linear, branched, or cyclic alkyl group or a phenyl, diphenyl, naphthyl, or dynaphthyl group, each optionally substituted. In particular, R7 may represent a linear Ci-s alkyl group, a branched C3-8 alkyl group, or an optionally substituted phenyl group. In particular, R7 may represent a linear C1-6 alkyl group, a branched C3-6 alkyl group, or an optionally substituted phenyl group. More particularly, R7 may represent a linear Ci-3 alkyl group or a branched C3 alkyl group.The possible optional substituents are one, two, three or four groups selected from i) halogens (particularly when the substituents are on aromatic residues), ii) Ci-g alkoxy, alkyl, alkenyl, or iii) a benzyl group or a condensed group or non-condensed phenyl group, the group being optionally substituted with one, two or three halogen, C1-8 alkyl, alkoxy, amino, nitro, ester, sulfonate or halo- or perhalo-hydrocarbon groups. According to any particular embodiment of the invention, the ligand P can be a monophosphite of formula P(OR7)3 where R7 has the same meaning defined above. According to any embodiment of the invention, the ligand P can be selected from the group consisting of triisopropyl phosphite, triphenyl phosphite, trioctyl phosphite, tricyclohexyl phosphite, trimethyl phosphite, triethyl phosphite, and triphenyl phosphite. According to any embodiment of the invention, the nickel catalyst is of formula (III) or (III'). In particular, the nickel catalyst is of formula (III). The nickel catalyst can be added to the reaction medium of the process of the invention to form the compound of formula (I) at a wide range of concentrations. Non-limiting examples of nickel catalyst concentrations range from 0.1 mol% to 7.5 mol% relative to the total amount of substrate. Specifically, the nickel catalyst concentration can range from 3 mol% to 6 mol%. It goes without saying that the process also works with higher catalyst concentrations. However, the optimum concentration of nickel catalyst will depend, as anyone skilled in the art knows, on the nature of the catalyst, the nature of the substrate, the temperature, and the desired reaction time. The nickel catalyst is a commercially available compound or can be prepared by various methods, such as that reported in Inorganic Chemistry 1964, 3,1062. The nickel catalyst of formula (III) or (III') or (III'') or (III''') is formed in situ by the reaction between a nickel (II) complex and a phosphine or phosphite, the P or PP ligand being as defined above, in the presence of a base such as an amine. The nickel (II) complex is hydrated. The nickel (II) complex can be selected from the group consisting of NiC12(H2O)x, NiBr2(H2O)x, Ni(OAc)2(H2O)x, NiSO4(H2O)xy, and NiI2(H2O)x, where x is an integer between 1 and 7. According to any embodiment of the invention, the process of the invention for forming the compound of formula (I) can be carried out in the absence of additives such as base or acid. According to any embodiment of the invention, the process of the invention for forming the compound of formula (I) is carried out at a temperature between 0°C and 150°C. In particular, the temperature is in the range between 30°C and 70°C. Of course, a person skilled in the art may also select the preferred temperature based on the melting and boiling points of the starting and final products, as well as the desired reaction or conversion time. reindeer ίη / ζζηζ / Ε / γίΛΐ The process of the invention for forming the compound of formula (I) can be carried out in the presence or absence of a solvent. When a solvent is required or used for practical reasons, any solvent stream may be used in such a reaction for the purposes of the invention. Non-limiting examples include C6-12 aromatic solvents such as xylene, toluene, 1,3-diisopropylbenzene, eumene, or pseudocumene, or mixtures thereof; hydrocarbon solvents such as cyclohexane, heptane, or mixtures thereof; nitrile solvents such as acetonitrile; steric solvents such as ethyl acetate; or ethereal solvents such as tetrahydrofuran, diethyl ether, methyltetrahydrofuran, or mixtures thereof. The choice of solvent depends on the nature of the substrate and / or the catalyst, and a person skilled in the art is able to select the most suitable solvent in each case to optimize the reaction. The process of the invention to form the compound of formula (I) is carried out under batch or continuous conditions. The process of the invention to form the compound of formula (I) can be carried out at atmospheric pressure. Surprisingly, the process of the invention for forming compounds of formula (I) allows forming compounds of formula (I) with the double bond in position 3 mainly with an E configuration. The compound of formula (IV), like the compound of formula (II'), is obtained by coupling an alkyne of formula (V) to a compound of formula (VI). The metal-catalyzed cross-coupling reaction has been widely reported in the prior art, particularly the palladium-catalyzed cross-coupling reaction. However, all the conditions reported in the prior art failed to provide the compound of formula (IV) from the alkyne of formula (V) and a compound of formula (VI). Therefore, a novel cross-coupling reaction, never mentioned or suggested in prior techniques, has been developed using a less expensive catalyst than palladium. Thus, another object of the present invention is a process for the preparation of a compound of formula (IV) R2R4R1-=--\ (IV) Y R3 in a form of any of its stereoisomers and wherein R1 represents a Ci-io hydrocarbon group, optionally substituted with one or more hydroxy, C1-15 alkoxy, C2-15 alkenyloxy, C3-15 heterocycloalkyl, Cg-io aryloxy and / or C1-4 carboxylic ester groups; R2, R3 and R4, independently of each other, represent a hydrogen atom, a C1-3 alkyl group or a phenyl group and Y is a hydrogen atom, a C1-3 alkyl group or a CHR5X group where R5 is a hydrogen atom, a C1-3 alkyl group or a phenyl group and X represents an OR6 group, an OC(=O)R6 group, an OC(=O)OR6 group or an OSO2R6 group, where R6 is a hydrogen atom or a C1-4 alkyl group or a phenyl group; reacting together a compound of formula reno Ln / zznz / E / YiAi in a form of any of its stereoisomers and wherein R1 has the same meaning as defined in formula (IV); with a compound of formula in a form of any of its stereoisomers and wherein X, Y, R2, R3, R4 and R5, independently of each other, have the same meaning as defined in formula (IV); in the presence of a nickel catalyst. Surprisingly, the process of the invention for forming the compound of formula (IV) allows the formation of the compound of formula (IV) while limiting the formation of the branched compound of formula (IV') reno Ln / zznz / E / YiAi in any of its stereoisomer forms, wherein R1, R2, R3, R4, and R5 have the same meaning as defined above. In particular, at most 50%, at most 40%, at most 30%, at most 25%, at most 20%, or at most 15% of the compound of formula (IV') are formed. According to any embodiment of the invention, Y can be a hydrogen atom or a CHR5X group, where R5 is a hydrogen atom, a C1-3 alkyl group, or a phenyl group, and X represents an OR6 group, an OC(=O)R6 group, an OC(=O)OR6 group, or an OSO2R6 group, where R6 is a hydrogen atom, a C1-4 alkyl group, or a phenyl group. In particular, Y can be a CHR5X group, where R5 is a hydrogen atom, a C1-3 alkyl group, or a phenyl group, and X represents an OR6 group, an OC(=O)R6 group, an OC(=O)OR6 group, or an OSO2R6 group, where R6 is a hydrogen atom, a C1-4 alkyl group, or a phenyl group. According to any embodiment of the invention, the reindeer ίη / 77Π7 / E / YΙΛΙ compound of formula (IV) is of formula (II') (IG) in a form of any of its stereoisomers and wherein R1 represents a Ci-io hydrocarbon group, optionally substituted with one or more hydroxy, C1-15 alkoxy, C2-15 alkenyloxy, C3-15 heterocycloalkyl, Ce-io aryloxy and / or C4-4 carboxylic ester groups; R2, R3, R4 and R5, independently of each other, represent a hydrogen atom, a C1-3 alkyl group or a phenyl group and X represents an ORS group, an OC(=O)R6 group, an OC(=O)OR6 group or an OSO2R6 group, wherein R6 is a hydrogen atom or a Ci-4 alkyl group or a phenyl group. According to any embodiment of the invention, the compound of formula (VI) is of formula (VII) in a form of any of its stereoisomers and wherein R2, R3, R4, R5 and each X, independently of each other, have the same meaning as defined in formula (II'). According to any embodiment of the invention, the nickel catalyst is of formula (III), (III'), (III'') or (III''') and has the same meaning as defined above; that is, as defined for the process of the invention for preparing the compound of formula (I). In particular, the nickel catalyst may be of formula (III) or (III'') wherein the ligand P may be a monodentate monophosphite ligand. The nickel catalyst used in both steps can be different or similar. Specifically, the nickel catalyst used in both steps is Ni(P(Oi-Pr)3) 4. Both steps can be carried out in one vessel. The nickel catalyst can be added to the reaction medium of the process of the invention to form the compound of formula (IV) in a wide range of concentrations. Non-limiting examples of nickel catalyst concentrations range from 0.1 mol% to 7.5 mol% of the total substrate. In particular, the nickel catalyst concentration can range from 3 mol% to 6 mol%. It goes without saying that the process also works with higher catalyst concentrations. However, the optimal concentration of nickel catalyst will depend, as anyone skilled in the art knows, on the nature of the catalyst, the nature of the substrate, the temperature, and the desired reaction time. Non-limiting examples of compounds suitable for formula (V) may include 1-propino, 1-butino, 1-heptino, 1pentino, 1-hexino, 1-octino, 1-nonino, 1-decino, phenylacetyleno, 4-pentinoato ethyl, (E)-3-metilpent-2-en-4-inl-ol, 2-metil-3-butin-2-ol, 7-metil-3-methylenooct-6-en-l-ino, l-etinil-3,3-dimetilciclohex-l-ol, l-etinil-5,5dimetilciclohex-l-eno, l-etinil-3,3-dimetilciclohex-l-eno y 3butin-l-ol. Non-limiting examples of compounds suitable for formula (VI) can include diacetate of but-2-eno-l,4-diilo, dipropionato of but-2-eno-l,4-diilo, dibenzoato of but-2-eno1,4-diilo, dipivalato of but-2-eno-l,4-diilo, acetato de allilo, acetato de 3-buten-2-ilo, acetato de crotilo, acetato de prenilo and acetato de cinnamilo. Non-limiting examples of suitable compounds of formula (IV) may include undec-2-en-5-in-l-yl acetate, (E)-undec-2-en-5-in-l-yl acetate, (E)-undec-2en-5-in-l-yl acetate, (E)-6-phenylhex-2-en-5-in-l-yl acetate, (E)ethyl 9-acetoxinon-7-en-4-inoate, (2E,7E)-9hydroxy-7-methylnonone-2,7-dien-5-in-l-yl acetate, (E)-8hydroxyoct-2-en-5-in-l-yl acetate, dec-l-en-4-yne, ethyl acetate (E)-7hydroxy-7-methyloct-2-en-5-in-l-yl, (E)-undec-2-en-5-yne, 10 methyl-6-methyleneundeca-l,9-dien-4-yne, 3,3-dimethyl-l-(pent-4en-l-in-l-yl)cyclohexan-1-ol, 5,5-dimethyl-l-(pent-4-en-l-yn-lyl)cyclohex-1-ene, 3,3-dimethyl-l-(pent-4-en-l-yn-lyl)cyclohex-l-ene, dec-l-en-4-yne and ethyl oct-7-en-4-inoate. According to any embodiment of the invention, the process of the invention for forming the compound of formula (IV) can be carried out in the absence of additives such as bases or acids. According to any embodiment of the invention, the process of the invention for forming the compound of formula (IV) is carried out at a temperature between 0°C and 150°C. In particular, the temperature is in the range of 15°C to 30°C. Of course, a person skilled in the art may also select a preferred temperature based on the melting and boiling points of the starting and final products, as well as the desired reaction or conversion time. The process of the invention for forming the compound of formula (IV) can be carried out in the presence or absence of a solvent. When a solvent is required or used for practical reasons, any solvent stream may be used in such a reaction for the purposes of the invention. Non-limiting examples include Ce-12 aromatic solvents such as xylene, toluene, 1,3-diisopropylbenzene, eumene, or pseudocumene, or mixtures thereof; hydrocarbon solvents such as cyclohexane, heptane, or mixtures thereof; nitrile solvents such as acetonitrile; and steric solvents such as isopropyl acetate. The choice of solvent depends on the nature of the substrate and / or the catalyst, and a person skilled in the art is able to select the most suitable solvent in each case to optimize the reaction. The process of the invention to form the compound of formula (IV) is carried out under batch or continuous conditions. The process of the invention to form the compound of formula (IV) can be carried out at atmospheric pressure. The compound of formula (II) is a new compound and has a number of advantages as explained above and shown in the Examples. Therefore, another object of the present invention is a compound of formula in any of its stereoisomer forms and wherein the dotted line is a carbon-carbon double or triple bond; R1 represents a linear or branched Ci-io alkyl, optionally substituted with one or more hydroxy, Ci-15 alkoxy, C2-15 alkenyloxy, C3-15 heterocycloalkyl, Cg-io aryloxy and / or C1-4 carboxylic ester groups; R2, R3, R4 and R5, independently of each other, represent a hydrogen atom, a C1-3 alkyl group or a phenyl group and X represents an ORS group, an OC(=O)R6 group, an OC(=O)OR6 group or an OSO2R6 group, wherein R6 is a hydrogen atom or a C1-4 alkyl group or a phenyl group. According to a particular modality, the compound of formula (II) is of formula in any form of its stereoisomers and wherein R1 represents a linear or branched C1-10 alkyl group, optionally substituted with one or more hydroxy, Ci-15 alkoxy, C2-15 alkenyloxy, C3-15 heterocycloalkyl, Ce-io aryloxy and / or C1-4 carboxylic ester groups; R2, R3, R4 and R5, independently of each other, represent a hydrogen atom, a C1-3 alkyl group or a phenyl group and X represents an 0Rs group, an OC(=O)R6 group, an OC(=O)OR6 group or an OSO2R6 group, wherein R6 is a hydrogen atom or a C1-4 alkyl group or a phenyl group. Typical ways of carrying out the invention process are reported below in the examples. Examples The invention will now be described in more detail by means of the following examples, where abbreviations have their usual meanings in the art, and temperatures are given in degrees Celsius (°C). The preparation of precatalyst and ligand solutions was carried out under an inert atmosphere (argon) using standard Schlenk techniques. The solvents were dried by conventional procedures and distilled in an argon atmosphere. NMR spectra were recorded at 20°C on Bruker AV 300, AV 400, or AV 500 MHz spectrometers. Chemical changes are reported in ppm relative to the solvent signals (chloroform, dH = 7.26 ppm, dC = 77.0 ppm). Signal assignment was ensured by recording the experiments 4H, 1H-COSY, -NOESY, 13C, 1H-HSQC, and -HMBC. Gas chromatography was performed on an Agilent 7890 A Series equipped with an HP5 column (30 m x 0.25 mm ID, 0.25 pm film) and tetradecane was used as an internal standard. Example 1 Preparation of (E)-undec-2-en-5-yn-l-yl acetate 27 g (0.25 equiv.) of triethylamine were introduced into a stirred suspension of 13 g (0.05 equiv.) of rene dichloride nickel hexahydrate and 28.5 g (0.125 equiv.) of triisopropylphosphite in 150 mL of isopropyl acetate. 188 g (1 equiv.) of 1,4-diacetoxy(Z)-but-2-ene was introduced, followed by 105 g (1 equiv.) of 1-heptyne, and the mixture was stirred at 20°C overnight. The reaction was then treated with aqueous Na₂EDTA followed by dilute potassium carbonate. The resulting product was concentrated under vacuum, then 230 g were subjected to ultra-rapid distillation and then fractionated in a packed 3m Sulzer laboratory apparatus. A first fraction (50°C / 5 mbar) was recovered consisting of unreacted 1-heptine (24 g, 22.8 %), followed by a second fraction (55-85°C / 3 mbar) consisting of a mixture of unreacted 1,4-diacetoxy but-2-ene and 2-vinylnon-3-in-yl acetate (81g) and a third fraction (102-110°C / 33°C) consisting of amber (E)-undec-2-en-5-in-l-yl (109 g, 98% purity, 48% yield). (E)-undec-2-en-5-in-heart acetate: NMR3H (CD2C12, 500 MHz) δ 0.9 (t, J = 7.0Hz, 3H, CH3) ; 1.34 (series of m, 4H, CH2) ; 1.49 (m, 2H, CH2) ; 2.03 (s, 3H, CH3) ; 2.17 (m, 2H, CH2) ; 2.9 (m width, 2H, CH2) ; 4.5 (width, J= 6.2Hz, 2H, CH2) ; 5.75 (m, 1H, CH) ; 5.85 (m, 1H, CH) . RMN13C (CD2CI2, 125 MHz), δ 14.2 (CH3) , 19.0 (CH2) , 21.1 (CH3) , 22.2 (CH2), 22.6 (CH2) , 29.2 (CH2) , 31.5 (CH2) , CH2 (CH2) , 31.5 (CH2) , 64.8 (C) , 83.4 (C) , 125.6 (=CH) , 130.7 (=CH) , 170.9 (CO) . Example 2 Preparation of (3E / Z)-1,3-Undecadiene~5-ino A suspension of 5.7 g of nickel dichloride hexahydrate was stirred at 25°C in 200 g of acetonitrile in the presence of 15 g of triisopropylphosphite. After 1 h of stirring, 36 g of triethylamine were added, followed by 100 g of (E)-undec-2-en-5-yn-l-yl acetate. The mixture was then heated to 50°C for 5 h. Once the reaction was complete, the mixture was cooled to 35°C, diluted with 200 g of cyclohexane, and washed twice with aqueous Na₂EDTA. Finally, the mixture was neutralized with dilute potassium bicarbonate and evaporated to dryness. The resulting oil (90 g) was rapidly distilled (50°C / l mbar) providing 58 g of 1,3-undecadien-5-yne (E / Z ratio 73:27) with a purity of 97% and a yield of 79%. (3E)-1,3-Undecadien-5-ine: NMR (CDC13, 400 MHz) δ 0.88 (t, J = 7.1Hz, 3H, CH3) ; 1.36 (serie de m, 4H, CH2) ; 1.53 (m, 2H, CH2) ; 2.3 (m, 2H, CH2) ; 5.12 (d ancho, J = 9.9Hz, 1H, CH2) ; 5.24 (d ancho, J = 16.2Hz, 1H, CH2) ; 5.63 (d, J = 15.1Hz, 1H, CH) ; 6.35 (dd, Ji = 15.1Hz, J2 = 16.2Hz, J3= 6.5Hz, 1H, CH) ; 6.49 (dd, Ji = 15.1Hz, J2 = 16.2Hz, 1H, CH) . RMN13C (CDCI3, 90 MHz) δ 13.9 (CH3) , 19.6 (CH2) , 22.2(CH2), 28.5 (CH2) , 31.1(CH2), 79.6(C), 93.6(C), 112.8 (=CH), 118.4 (=CH2) , 136.4(=CH), 140.9 (=CH) . Ejemplo 3 Preparación de (2E,5Z)-undeca-2,5-dien-l-ilo (E)-Undec-2-en-5-yn-l-yl acetate, Lindlar's catalyst (0.11 wt.%, 0.011 mol.% of Pd), and 3,6-dithia-1,8-octanediol (Lindlar's catalyst poison, CAS No. 5244-34-8) (0.0014 wt.%, 0.0016 mol.%, i.e., approximately 15 mol.% relative to Pd) were loaded into a 100 ml oil-equipped autoclave with a mechanical seating device, internal pressure and temperature sensors, and a heating / cooling system for internal temperature regulation. The sealed autoclave was then purged with agitation using nitrogen (3 times 5 bar) before being agitated at 25°C under a nitrogen pressure of 1 bar for 30 minutes.After this period, the autoclave was purged under agitation with hydrogen (3 times 1 bar) before being pressurized to 1 bar of hydrogen pressure via a hydrogen tank equipped with an outlet pressure regulator and an internal pressure sensor to monitor and determine hydrogen consumption. The reaction mixture was then stirred (1000 rpm) at 50°C under a hydrogen pressure of 3 bar, which was maintained throughout the reaction. Once the hydrogenation of the alkyne was complete (2 to 3 hours), as determined by GC analysis on a short polar column (DB-Wax 10 m x 0.1 mm x 0.1 mm), the autoclave was cooled to room temperature, agitation was stopped, and the autoclave was depressurized and purged with nitrogen (3 times 5 bar). The reaction mixture was then passed through filtration equipment to remove the Lindlar catalyst.The desired (2E,5Z)-undeca-2,5-dien-l-yl acetate was obtained with complete conversion, ratio 99 / 1 (2E,5Z) / (2E,5E), more than 1. 99.5% GC chemoselectivity and no residues formed (determined by bulb-to-bulb distillation of sample) without any additional purification. (2E,5Z)-undeca-2,5-dien-l-yl acetate: NMR7Η (400 MHz, CD2C12) : δ (ppm) 0.88 (t, J = 6.9 Hz, 3H, CH3), 1.20-1.40 (m, 6H, 3 CH2), 1.98-2.08 (m, 5H, CH2+ CH3), 2.80 (t, J = 6.8 Hz, 2H, CH2), 4.48 (dd, Ji = 6.4, J2=l. 0 Hz, 2H, CH2), 5.30-5.40 (m, 1H, =CH), 5.42-5.52 (m, 1H, =CH), 5.53-5.63 (m, 1H, =CH), 5.70-5.80 (m, 1H, =CH). 13C NMR (100 MHz, CD2C12) : δ (ppm) 14.2 (CH3), 21.1 (CH3), 23.0 (CH2), 27.5 (CH2), 29.7 (CH2), 30.4 (CH2), 31.9 (CH2), 65.3 (CH2), 124.7 (=CH), 126.5 (=CH), 131.9 (=CH), 134.6 (=CH), 170.9 (CO) . Example 4 Preparation of (3E,5Z)-1,3,5-undecatriene A suspension of 5.7 g of nickel dichloride hexahydrate was stirred at 25°C in 200 g of acetonitrile in the presence of 15 g of triisopropylphosphite. After 1 h of stirring, 36 g of triethylamine were added, followed by 100 g of (2E,5Z)-undeca-2,5-dien-l-yl(Ib) acetate. The mixture was then heated to 50°C for 5 h. After the reaction was complete, the mixture was cooled to 35°C, picked up with 200 g of cyclohexane, and washed twice with aqueous Na₂EDTA. Finally, the mixture was neutralized with dilute potassium bicarbonate and evaporated to dryness. The resulting oil (92 g) was rapidly distilled (50°C / l mbar) providing 63 g of (3E,5Z)-1,3,5-undecatriene (3E / 3Z ratio 98:2) with a purity of 95% and a yield of 85%. (3E,5Z)-1,3,5-undecatriene: RMNXH (CDC13, 400 MHz) δ 0.89 (t, J = 7.1Hz, 3H, CH3) , 1.31 (serie de m, 4H, CH2) , 1.38 (m, 2H, CH2) , 2.2 (m, 2H, CH2) ; 5.12 (d ancho, J = 10.6 Hz, 1H, CH2), 5.24 (d ancho, J = 17.0Hz, 1H, CH2) , 5.5 (m, 1H, CH), 6.0 (t broad, J = 15.1Hz, 1H, CH) , 6.2 (dd, Ji = 15.1Hz, J2 = 10.6Hz, 1H, CH) , 6.4 (m, 2H, CH) . RMN13C (CDCI3, 100 MHz) δ 14.0 (CH3) , 22.7 (CH2), 27.9 (CH2) , 29.5 (CH2), 31.6(CH2), 116.7(=CH2), 128.4 (CH) , 128.8 (CH), 133.0 (CH), 133.6(CH), 137.4 (CH). Ejemplo 5 Preparación de acetato de (E)-6-Fenilhex-2-en-5-in-l-ilo 0.66 g (0.25 equiv.) of triethylamine was introduced into a stirred suspension of 0.31 g (0.05 equiv.) of nickel dichloride hexahydrate and 0.68 g (0.125 equiv.) of triisopropylphosphite in 3.6 mL of isopropyl acetate. 4.48 g (1 equiv.) of 1,4-diacetoxy(Z)-but-2-ene was introduced, followed by 2.66 g (1 equiv.) of phenylacetylene, and the mixture was stirred at 20°C overnight. The reaction was then treated with aqueous Na₂EDTA followed by dilute potassium carbonate. The reaction mixture containing 31% unreacted phenylacetylene GC, 46% (E)-6-phenylhex-2-en5-yn-l-yl GC, and 15% 2-(phenylethynyl)but-3-yn-1-yl GC (linear / branched ratio 75 / 25) was purified by silica gel chromatography (30 / 50 petroleum ether / Et20 10 / 0 to 9 / 1) for the isolation of the pure products. (E)-6-phenylhex-2-en-5-yn-l-yl acetate (main product): 3H NMR (CDC13, 500 MHz) δ 2.07 (s, 3H, CH3) , 3.21 (dq wide, J = 5.2 and 1.4 Hz, 2H, CH2) , 4.59 (dq wide, J = 6.2 and 1.1 Hz, 2H, CH2) , 5.84 (dtt, J = 15.2, 5.2 and 1.1 Hz,1H, alkene CH), 5.94 (dtt, J = 15.2, 6.2 and 1.4 Hz, 1H, alkene CH), 7.27-7.32 (m, 3H, 3 CH Ar), 7.39-7.45 (m, 2H, 2 CH Ar). 13C NMR (CDC13, 125 MHz), δ 21.0 (CH3) , 22.4 (CH2) ,64.5 (CH2) , 83.0 (alkyne C), 86.1 (alkyne C), 123.5 (C Ar), 125.8 (alkene CH) , 127.9 (CH Ar) , 128.2 (2 CH Ar), 129.4 (alkene CH), 131.6 (2 CH Ar), 170.8 (ester C). 2-(Phenylethynyl)but-3-en-l-yl acetate (byproduct): RMN3H (CDC13, 500 MHz) δ 2.09 (s, 3H, CH3) , 3.21 (dt, J = 7.0 y 6.0 Hz, 1H, CH) , 4.18 (dd, J = 10.6 y 7.0 Hz, 1H, CH2), 4.24 (dd, J = 10.6 y 7.0 Hz, 1H, C 17.0, 10.0 y 6.0 Hz, 1H, alqueno CH), 7.27-7.32 (m, 3H, 3 CH Ar), 7.39-7.45 (m, 2H, 2 CH Ar) . RMN13C (CDCI3, 125 MHz), δ 20.9 (CH3), 36.1 (CH), 66.0 (CH2), 84.6 (alquine C), 86.4 (alquine C), 117.8 (alquine CH2) , 123.1 (C Ar) , 128.1 (CH Ar) , 128.3 (2 CH Ar) , 131.7 (2 CH Ar), 133.6 (alqueno CH), 170.8 (ester C). Example 6 Preparation of (E)-9-acetoxinon-7-en-4-inoate ethyl 0.66 g (0.25 equiv.) of triethylamine was introduced into a stirred suspension of 0.31 g (0.05 equiv.) of nickel dichloride hexahydrate and 0.68 g (0.125 equiv.) of triisopropylphosphite in 3.6 mL of isopropyl acetate. 4.48 g (1 equiv.) of 1,4-diacetoxy(Z)-but-2-ene was introduced, followed by 3.28 g (1 equiv.) of ethyl 4-pentinoate, and the mixture was stirred at 20°C overnight. The reaction was then treated with aqueous Na₂EDTA followed by dilute potassium carbonate. The reaction mixture containing 30% unreacted ethyl 4-pentinoate GC, 45% ethyl 9-acetoxinon-7-en-4-inyoate GC, and 17% ethyl 6-(acetoxymethyl)oct-7-en-4-inyoate GC (linear / branched ratio 72 / 28) was purified by silica gel chromatography (30 / 50 petroleum ether / Et20 10 / 0 to 8 / 2) for the isolation of pure products 9-Acetoxinon-7-en-4-inoate ethyl (main product): 3H NMR (CDC13, 500 MHz) δ 1.26 (t, J = 7.1 Hz, 3H, CH3), 2.07 (s, 3H, CH3) , 2.51 (s, 4H, 2 CH2) , 2.93 (d, J = 5.0 Hz, 2H, CH2) , 4.16 (q, J = 7.1 Hz, 2H, CH2) , 4.55 (d, J = 6.0 Hz, 2H, CH2) , 5.74 (dt, J = 15.2 and 5.0 Hz, 1H, CH alkene), 5.84 (dt, J = 15.2 and 6.0 Hz, 1H, CH alkene). NMR13C (CD2C12, 125 MHz), δ 14.4 (CH3) , 15.1 (CH2) , 21.1 (CH3) , 22.0 (CH2), 34.3 (CH2) , 60.9 (CH2) , 64.7 (CH2) , 77.3 (alkyne C), 81.4 (alkyne C), 125.8 (alkene CH), 130.2 (alkene CH), 170.9 (ester C), 172.3 (ester C). (Note: the NMR spectrum of 13C is given in CD2C12 instead of CDC13 due to some quaternary carbon signal from the alkyne moiety hidden in CDC13). 6-(Acetoxymethyl)oct-7-en-4-ynoate ethyl (byproduct): 3H NMR (CDCI3, 500 MHz) δ 1.26 (t, J = 7.1 Hz, 3H, CH3), 2.07 (s, 3H, CH3), 2.52 (s, 4H, 2 CH2), 3.37 (dt, J = 7.1 and 6.0 Hz, 1H, CH), 4.03 (dd, J = 10.5 and 7.1 Hz, 1H, CH2), 4.10 (dd, J = 10.5 and 7.1 Hz, 1H, CH2), 4.15 (q, J = 7.1 Hz, 2H, CH2), 5.18 (dt, J = 10.1 and 1.3 Hz, 1H, alkene CH2), 5.37 (dt, J = 16.5 and 1.3 Hz, 1H, alkene CH2), 5.75 (ddd, J = 16.5, 10.1 and 6.0 Hz, 1H, alkene CH) . 13C NMR (CDCI3, 125 MHz), δ 14.2 (CH3) , 14.8 (CH2) , 20.9 (CH3) , 33.9 (CH2) , 35.4 (CH) , 60.6 (CH2) , 66.2 (CH2) , 77.7 (alkyne C) , 82.9 (alkyne C) , 113.4 (alkene CH2) , 134.1 (alkene CH), 170.8 (ester C), 172.0 (ester C). Example 7 Preparation of (2E,7E)-9-hydroxy-7-methylnona-2,7-dien-5-yn-l-yl acetate 0.66 g (0.25 equiv.) of triethyl lamine was introduced into a stirred suspension of 0.32 g (0.05 equiv.) of nickel diacetate tetrahydrate and 0.68 g (0.125 equiv.) of triisopropylphosphite in 3.6 ml of isopropyl acetate. 4.48 g (1 equiv.) of 1,4-diacetoxy(Z)-but2-ene was introduced, followed by 2.50 g (1 equiv.) of (E)-3-methylpent-2-en-4-yn-l, and the mixture was stirred at 20°C for 4 h. The reaction was then treated with aqueous Na2EDTA followed by dilute potassium carbonate. The reaction mixture containing 17% GC of unreacted (E)-3-methylpent-2-en-4-yn-l-ol, 54% GC of (2E,7E)-9-hydroxy-7methylnona-2,7-dien-5-yn-l-yl acetate and 21% GC of (E)-7hydroxy-5-methyl-2-vinylhept-5-en-3-yn-l-yl acetate (linear / branched ratio 72 / 28) was purified by silica gel chromatography (30 / 50 petroleum ether / Et2O 10 / 0 to 6 / 4) for the isolation of pure products. (2E,7E)-9-hydroxy-7-methylnona-2,7-dien-5-yn-lyl acetate (main product): RMNXH (CDC13, 500 MHz) δ 1.82 (s wide, 3H, CH3), 1.86 (s wide, 1H, OH), 2.07 (s, 3H, CH3), 3.09 (d wide, J = 4.8 HZ, 2H, CH2), 4.21 (d, J = 7.0 Hz, 2H, CH2), 4.56 (dd, J = 6.2 and 1.1 Hz, 2H, CH2), 5.77 (dt wide, J = 15.4 and 4.8 Hz, 1H, alkene OH), 5.86 (dtt, J = 15.4, 6.2 and 1.4, 1H, alkene CH), 5.95 (tq wide, J = 7.0 and 1.3 Hz, 1H, alkene CH). 13C NMR (CDCI3, 125 MHz), δ 17.8 (CH3) , 21.0 (CH3) , 22.3 (CH2) , 59.0 (CH2) , 64.5 (CH2) , 84.3 (alkyne C) , 85.2 (alkyne C), 120.8 (alkene C), 125.6 (alkene CH), 129.5 (alkene CH), 134.8 (alkene CH), 170.9 (ester C) . (E)-7-hydroxy-5-methyl-2-vinylhept-5-en-3-yn-lyl acetate (byproduct): 3H NMR (CDCI3, 500 MHz) δ 1.75 (s wide, 1H, OH), 1.83 (s wide, 3H, CH3), 2.08 (s, 3H, CH3), 3.52 (q, J = 6.6 Hz, 1H, CH), 4.10 (dd, J = 10.6 and 6.6 Hz, 1H, CH2), 4.15 (dd, J = 10.6 and 6.6 Hz, 1H, CH2), 4.22 (d, J = 6.8 Hz, 2H, CH2), 5.22 (dt, J = 10.0 and 1.3 Hz, 1H, alkene CH2), 5.40 (dt, J = 17.0 and 1.3 Hz, 1H, alkene CH2) , 5.79 (ddd, J = 17.0, 10.0 and 6.6 Hz, 1H, alkene CH), 5.97 (tq, J = 6.8 and 1.4 Hz, 1H, alkene CH) 13C NMR (CDCI3, 125 MHz), δ 17.7 (CH3) , 20.9 (CH3) , 59.0 (CH2) , 66.0 (CH2) , 84.6 (alkyne C) , 86.8 (alkyne C) , 117.7 (alkene CH2) , 120.6 (alkene C) , 133.7 (alkene CH) , 135.2 (alkene CH) , 170.9 (ester C) . Example 8 Preparation of (E)-8-hydroxyoct-2-en-5-yn-lyl acetate 0.66 g (0.25 equiv.) of triethylamine was introduced into a stirred suspension of 0.32 g (0.05 equiv.) of nickel diacetate tetrahydrate. 68 (0.125 equiv.) of reno Ln / zznz / E / YiAi triisopropylphosphite was added in 3.6 ml of isopropyl acetate. 4.48 g (1 equiv.) of 1,4-diacetoxy (Z)-but-2-ene was introduced, followed by 1.82 g (1 equiv.) of 3-butyn-1-ol, and the mixture was stirred at 20°C for 24 h. The reaction was then treated with aqueous Na2EDTA followed by dilute potassium carbonate. Thanks to GC-MS and NMR analysis, it was determined that the crude mixture contained 51% unreacted 3-butyn-l-ol GC, 32% (E)-8-hydroxyoct-2-en-5-yn-l-yl acetate GC and 11% 6-hydroxy-2-vinylhex-3-yn-l-yl acetate GC (linear / branched ratio 75 / 25). Example 9 Preparation of (E)-undec-2-en-5-yn-l-yl benzoate 0.66 g (0.25 equiv.) of triethylamine was introduced into a stirred suspension of 0.31 g (0.05 equiv.) of nickel dichloride hexahydrate and 0.68 g (0.125 equiv.) of triisopropylphosphite in 3.6 ml of isopropyl acetate. 7.70 g (1 equiv.) of (Z)-but-2-ene-1,4-diyl dibenzoate was introduced, followed by 2.5 g (1 equiv.) of heptin, and the mixture was stirred at 20°C for 20 h. The reaction was then treated with aqueous Na₂EDTA followed by dilute potassium carbonate. Thanks to GC-MS and NMR analyses, it was determined that the crude mixture contained 51% unreacted heptin GC, 26% (E)-undec-2-en-5-yn-l-yl benzoate GC, and 10% 2-vinylnon-3-yn-l-yl benzoate GC (linear / branched ratio 72 / 28). Example 10 Preparation of Dec-l-en-4-ino 0.66 g (0.25 equiv.) of triethylamine was introduced into a stirred suspension of 0.32 g (0.05 equiv.) of nickel diacetate tetrahydrate and 0.68 g (0.125 equiv.) of triisopropylphosphite in 3.6 mL of isopropyl acetate. 2.60 g (1 equiv.) of allyl acetate was introduced, followed by 2.5 g (1 equiv.) of heptin, and the mixture was stirred at 20°C for 18 h. The reaction was then treated with aqueous Na₂EDTA followed by dilute potassium carbonate. GC-MS and NMR analysis determined that the crude mixture contained 10% unreacted heptin and 78% dec-l-en-4-yne. Example 11 Preparation of (E)-undec-2-en-5-ino 0.66 g (0.25 equiv.) of triethylamine was introduced into a stirred suspension of 0.32 g (0.05 equiv.) of nickel diacetate tetrahydrate and 0.68 g (0.125 equiv.) of triisopropylphosphite in 3.6 mL of isopropyl acetate. 2.97 g (1 equiv.) of 3-buten-2-yl acetate was then introduced, followed by 2.5 g (1 equiv.) of heptin, and the mixture was stirred at 20°C for 18 h. The reaction was then treated with aqueous Na₂EDTA followed by dilute potassium carbonate. GC-MS and NMR analyses determined that the crude mixture contained 10% unreacted heptin. 40% GC of (E)-undec-2-en-5-yne and 40% GC of 3-methyldec-l-en-4-yne (linear / branched ratio 50 / 50). Example 12 Preparation of ethyl (E)-9-acetoxin-7-en-4-inoate 0.66 g (0.25 equiv.) of triethylamine were introduced into a stirred suspension of 0.32 g (0.05 equiv.) of nickel diacetate tetrahydrate and 0.68 g (0.125 equiv.) of triisopropylphosphite in 3.6 ml of isopropyl acetate. 2.60 g (1 equiv.) of allyl acetate were introduced, followed by 3.28 g (1 equiv.) of ethyl 4-pentinoate, and the mixture was stirred to The reaction was heated at 20°C for 8 h. The reaction was then treated with aqueous Na2EDTA followed by dilute potassium carbonate. GC-MS and NMR analysis determined that the crude mixture contained 13% unreacted ethyl 4-pentinoate and 80% ethyl oct-7-en-4-inoate. It is hereby stated that, as of this date, the best method known to the applicant for putting the aforementioned invention into practice is the one that is clear from the present description of the invention.

Claims

5 1. A process for the preparation of a compound of formula (I) R2 R4 Rl—“--(I) io R3 in a form of any of its stereoisomers or a mixture thereof and wherein the dotted line is a carbon-carbon double bond or a carbon-carbon triple bond and R1 represents a C1-io hydrocarbon group, optionally comprising one or more 15 hydroxy, C1-15 alkoxy, C2-15 alkenyloxy, C3-15 heterocycloalkyl, Cg-io aryloxy and / or C1-4 carboxylic ester groups and R2, R3, R4 and R5, independently of each other, represent a hydrogen atom, a C1-3 alkyl group or a phenyl group;characterized in that it comprises the reaction of a compound of formula (II) R2 R4 R1--R3 R5 in a form of any of its stereoisomers and in reno ίη / 77Π7 / E / YILI where the dotted line, R1, R2, R3, R4 and R5 have the same meaning defined in formula (I) and X represents an OR6 group, an OC(=O)R6 group, an OC(=O)OR6 group or an OSO2R6 group, wherein R6 is a hydrogen atom or a C1-4 alkyl group or a phenyl group; with a nickel catalyst.; 2. The process according to claim 1, characterized in that R1 represents a linear C1-10 alkyl group, a linear C2-io alkenyl group, a branched C3-10 alkyl or alkenyl group, or a Cg-io aryl group, optionally comprising a hydroxy group or C1-4 carboxylic ester group.

3. The process according to claim 1 or 2, characterized in that R1 represents a linear C4-8 alkyl group, preferably a pentyl group.

4. The process according to any of claims 1 to 3, characterized in that X represents an OC(=O)R6 group wherein R6 is a Ci-3 alkyl group.

5. The process in accordance with any of claims 1 to 4, characterized in that X represents an acetate group.

6. The process according to any of claims 1 to 5, characterized in that R2, R3, R4 and R5 are hydrogen atoms.

7. The process according to any of claims 1 to 6, characterized in that the nickel catalyst is of formula [Ni(P)4] (III) or [Ni(PP)2] (III') or [Ni(P)2ML] (III'') or [Ni(PP)ML] (III''') wherein each P represents, independently of each other, a C3-C30 monodentate ligand wherein the coordination groups are one phosphorus atom and each PP represents, independently of each other, a C5-C50 bidentate ligand wherein the coordination groups are two phosphorus atoms; and M and L, independently of each other, are an anionic or neutral ligand, provided that when M is a neutral ligand, L is a neutral ligand and when M is an anionic ligand, L is an anionic ligand.

8. The process according to any of claims 1 to 7, characterized in that P is a monophosphite of formula P(OR7)3 wherein R7 is a C1-6 linear alkyl group, a C3-6 branched alkyl group or a phenyl group.

9. The process according to any of claims 1 to 8, characterized in that the nickel catalyst of formula (III), (III') (III'') or (III''') is formed in situ by the reaction between a nickel (II) complex and a phosphite or phosphine in the presence of a base such as an amine.

10. The process according to any one of claims 1 to 9, characterized in that the compound of formula (I) is of formula reno Ln / zznz / E / YiAi in a form of any of its stereoisomers or a mixture thereof and wherein R1, R2, R3, R4 and R5 have the same meaning as defined in claim 1; and the compound of formula (II) is of formula in a form of any of its stereoisomers and wherein R1, R2, R3, R4, R5 and X have the same meaning as defined in claim 1.

11. The process according to any one of claims 1 to 9, characterized in that the compound of formula (I) is of formula R2 R4 (I) R3 in a form of any of its stereoisomers or a mixture thereof and wherein R1, R2, R3, R4 and R5 have the same meaning as defined in claim 1; and the compound of formula (II) is of formula R2 R4<ir'> R3 R5 in a form of any of its stereoisomers and wherein R1, R2, R3, R4, R5 and X have the same meaning as defined in claim 1.

12. The process according to claim 11, characterized in that the compound of formula (II'') is obtained by the reduction of the compound of formula (II').

13. A process for the preparation of a compound of formula (IV) R2 R4 Rl—::=---\ (IV) Y R3 in a form of any of its stereoisomers and wherein R1 represents a Ci-io hydrocarbon group, optionally substituted with one or more hydroxy, C1-15 alkoxy, C215 alkenyloxy, C3-15 heterocycloalkyl, Ce-io aryloxy and / or C1-4 carboxylic ester groups; R2, R3 and R4, independently of each other, represent a hydrogen atom, a C1-3 alkyl group or a phenyl group and Y is a hydrogen atom, a C1-3 alkyl group or a CHR5X group wherein R5 is a hydrogen atom, a C1-3 alkyl group or a phenyl group and X represents an OR6 group, an OC(=O)R6 group, an OC(=O)OR6 group or an OSO2R6 group, wherein R6 is a hydrogen atom or a C1-4 alkyl group or a phenyl group; characterized in that a compound of formula Ri--== (V) is reacted together in a form of any of its stereoisomers and wherein R1 has the same meaning as defined in formula (IV);with a compound of formula in one form of any of its stereoisomers and wherein X, Y, R2, R3 and R4 have the same meaning as defined in formula (IV); in the presence of a nickel catalyst.; 14. The process according to claim 13, characterized in that the nickel catalyst is as defined in claims 7 to 9.

15. A compound of formula reno Ln / zznz / E / YiAi in any of its stereoisomeric forms and wherein the dotted line is a carbon-carbon double bond or a carbon-carbon triple bond; R1 represents a linear or branched Ci-io alkyl group, optionally substituted with one or more hydroxy, C1-15 alkoxy, C2-15 alkenyloxy, C3-15 heterocycloalkyl, Ce-io aryloxy and / or Ci4 carboxylic ester groups; R2, R3, R4 and R5, independently of each other, represent a hydrogen atom, a C1-3 alkyl group or a phenyl group and X represents an OR6 group, an OC(=O)R6 group, an OC(=O)OR6 15 group or an OSO2R6 group, characterized in that R6 is a hydrogen atom or a C1-4 alkyl group or a phenyl group.