The present invention relates to a 6-hydroxy-3-hexenyl alkoxymethyl ether compound of the following general formula (1): HOCH.sub.2CH.sub.2CH═CHCH.sub.2CH.sub.2OCH.sub.2OCH.sub.2R′ (1), R.sup.1 representing a hydrogen atom, an n-alkyl group having 1 to 9 carbon atoms, or a phenyl group; and also relates to a process for preparing a 3,13-octadecadien-1-ol compound of the following formula (6): CH.sub.3(CH.sub.2).sub.3CH═CH(CH.sub.2).sub.8CH═CHCH.sub.2CH.sub.2OH (6) from the 6-hydroxy-3-hexenyl alkoxymethyl ether compound (1).

The present invention relates to a 6-hydroxy-3-hexenyl alkoxymethyl ether compound of the following general formula (1): HOCH.sub.2CH.sub.2CH═CHCH.sub.2CH.sub.2OCH.sub.2OCH.sub.2R′ (1), R.sup.1 representing a hydrogen atom, an n-alkyl group having 1 to 9 carbon atoms, or a phenyl group; and also relates to a process for preparing a 3,13-octadecadien-1-ol compound of the following formula (6): CH.sub.3(CH.sub.2).sub.3CH═CH(CH.sub.2).sub.8CH═CHCH.sub.2CH.sub.2OH (6) from the 6-hydroxy-3-hexenyl alkoxymethyl ether compound (1).

The present invention relates to an acetal compound of the following general formula (1) and an acetal compound of the following general formula (2). The present invention relates to processes for preparing the acetal compound (2), comprising subjecting the acetal compound (1) to a hydrogenation reaction to form the acetal compound (2). The present invention provides a process for preparing 2,3,4,4-tetramethylcyclopentanecarbaldehyde of the following formula (3), comprising subjecting the acetal compound (2) to a hydrolysis reaction to form 2,3,4,4-tetramethylcyclopentanecarbaldehyde (3). ##STR00001##

The present invention relates to an acetal compound of the following general formula (1) and an acetal compound of the following general formula (2). The present invention relates to processes for preparing the acetal compound (2), comprising subjecting the acetal compound (1) to a hydrogenation reaction to form the acetal compound (2). The present invention provides a process for preparing 2,3,4,4-tetramethylcyclopentanecarbaldehyde of the following formula (3), comprising subjecting the acetal compound (2) to a hydrolysis reaction to form 2,3,4,4-tetramethylcyclopentanecarbaldehyde (3). ##STR00001##

The present invention relates to an acetal compound of the following general formula (1) and an acetal compound of the following general formula (2). The present invention relates to processes for preparing the acetal compound (2), comprising subjecting the acetal compound (1) to a hydrogenation reaction to form the acetal compound (2). The present invention provides a process for preparing 2,3,4,4-tetramethylcyclopentanecarbaldehyde of the following formula (3), comprising subjecting the acetal compound (2) to a hydrolysis reaction to form 2,3,4,4-tetramethylcyclopentanecarbaldehyde (3). ##STR00001##

The present invention relates to a process for preparing a (4Z)-11,11-dialkoxy-4-undecenyltriarylphosphonium halide compound of the following general formula (3-Z): wherein Y represents a halogen atom, Ar represents, independently of each other, an aryl group, and R.sup.1 and R.sup.2 represent, independently of each other, a monovalent hydrocarbon group having 1 to 15 carbon atoms, or R.sup.1 and R.sup.2 may form together a divalent hydrocarbon group, R.sup.1-R.sup.2, having 2 to 10 carbon atoms, the process comprising: subjecting a (7Z)-11-halo-1,1-dialkoxy-7-undecene compound of the following general formula (1-Z): wherein X.sup.1 represents a halogen atom, and R.sup.1 and R.sup.2 are as defined above to a phosphonium salt formation reaction with a phosphine compound of the following general formula (2): wherein Ar is as defined above to form the (4Z)-11,11-dialkoxy-4-undecenyltriarylphosphonium halide compound (3-Z).

##STR00001##

The present invention also relates to a compound of the following general formula (A): L(CH.sub.2).sub.3CH═CH(CH.sub.2).sub.5CH(OR.sup.1)(OR.sup.2) (A) wherein R.sup.1 and R.sup.2 are as defined above.

The present invention relates to a process for preparing a (4Z)-11,11-dialkoxy-4-undecenyltriarylphosphonium halide compound of the following general formula (3-Z): wherein Y represents a halogen atom, Ar represents, independently of each other, an aryl group, and R.sup.1 and R.sup.2 represent, independently of each other, a monovalent hydrocarbon group having 1 to 15 carbon atoms, or R.sup.1 and R.sup.2 may form together a divalent hydrocarbon group, R.sup.1-R.sup.2, having 2 to 10 carbon atoms, the process comprising: subjecting a (7Z)-11-halo-1,1-dialkoxy-7-undecene compound of the following general formula (1-Z): wherein X.sup.1 represents a halogen atom, and R.sup.1 and R.sup.2 are as defined above to a phosphonium salt formation reaction with a phosphine compound of the following general formula (2): wherein Ar is as defined above to form the (4Z)-11,11-dialkoxy-4-undecenyltriarylphosphonium halide compound (3-Z).

##STR00001##

The present invention also relates to a compound of the following general formula (A): L(CH.sub.2).sub.3CH═CH(CH.sub.2).sub.5CH(OR.sup.1)(OR.sup.2) (A) wherein R.sup.1 and R.sup.2 are as defined above.

Provided are a method for efficiently producing an asymmetric conjugated diyne from an inexpensive and safe alternative compound to hydroxylamine hydrochloride and a method for producing a Z,Z-conjugated diene compound from the asymmetric conjugated diyne compound thus obtained. More specifically, provided is a method for producing an asymmetric conjugated diyne compound comprising a step of subjecting a terminal alkyne compound (1): HC≡C—Z.sup.1—Y.sup.1 to a coupling reaction with an alkynyl halide (2): Y.sup.2—Z.sup.2—C≡C—X by using sodium borohydride in water and an organic solvent in the presence of a copper catalyst and a base to obtain the asymmetric conjugated diyne compound (3): Y.sup.2—Z.sup.2—C≡C—C≡C—Z.sup.1—Y.sup.1. In addition, provided is a method for producing a Z,Z-conjugated diene compound by reducing the resulting asymmetric conjugated diyne compound, or the like.

Provided are a method for efficiently producing an asymmetric conjugated diyne from an inexpensive and safe alternative compound to hydroxylamine hydrochloride and a method for producing a Z,Z-conjugated diene compound from the asymmetric conjugated diyne compound thus obtained. More specifically, provided is a method for producing an asymmetric conjugated diyne compound comprising a step of subjecting a terminal alkyne compound (1): HC≡C—Z.sup.1—Y.sup.1 to a coupling reaction with an alkynyl halide (2): Y.sup.2—Z.sup.2—C≡C—X by using sodium borohydride in water and an organic solvent in the presence of a copper catalyst and a base to obtain the asymmetric conjugated diyne compound (3): Y.sup.2—Z.sup.2—C≡C—C≡C—Z.sup.1—Y.sup.1. In addition, provided is a method for producing a Z,Z-conjugated diene compound by reducing the resulting asymmetric conjugated diyne compound, or the like.

Provided are a method for efficiently producing an asymmetric conjugated diyne from an inexpensive and safe alternative compound to hydroxylamine hydrochloride and a method for producing a Z,Z-conjugated diene compound from the asymmetric conjugated diyne compound thus obtained. More specifically, provided is a method for producing an asymmetric conjugated diyne compound comprising a step of subjecting a terminal alkyne compound (1): HC≡C—Z.sup.1—Y.sup.1 to a coupling reaction with an alkynyl halide (2): Y.sup.2—Z.sup.2—C≡C—X by using sodium borohydride in water and an organic solvent in the presence of a copper catalyst and a base to obtain the asymmetric conjugated diyne compound (3): Y.sup.2—Z.sup.2—C≡C—C≡C—Z.sup.1—Y.sup.1. In addition, provided is a method for producing a Z,Z-conjugated diene compound by reducing the resulting asymmetric conjugated diyne compound, or the like.