There are provided methods of efficiently producing compounds that are, for example, sex pheromones of San Jose Scale. For example, there is provided a method for producing a 7-methyl-3-methylene-7-octenyl carboxylate compound (4), the method including the steps of: hydrolyzing a 7-methyl-3-methylene-7-octenal acetal compound (1) to obtain 7-methyl-3-methylene-7-octenal (2); reducing the 7-methyl-3-methylene-7-octenal (2) to obtain 7-methyl-3-methylene-7-octenol (3); and esterifying the 7-methyl-3-methylene-7-octenol (3) to obtain a 7-methyl-3-methylene-7-octenyl carboxylate compound (4). ##STR00001##

There are provided methods of efficiently producing compounds that are, for example, sex pheromones of San Jose Scale. For example, there is provided a method for producing a 7-methyl-3-methylene-7-octenyl carboxylate compound (4), the method including the steps of: hydrolyzing a 7-methyl-3-methylene-7-octenal acetal compound (1) to obtain 7-methyl-3-methylene-7-octenal (2); reducing the 7-methyl-3-methylene-7-octenal (2) to obtain 7-methyl-3-methylene-7-octenol (3); and esterifying the 7-methyl-3-methylene-7-octenol (3) to obtain a 7-methyl-3-methylene-7-octenyl carboxylate compound (4). ##STR00001##

The present invention provides a process for preparing a terminal conjugated alkadienal compound of the following general formula (5):
CH.sub.2═CHCH═CH(CH.sub.2).sub.aCHO   (5)
wherein “a” represents an integer of 1 to 15, from a dialkoxyalkenyl alkoxymethyl ether compound of the following general formula (1):
R.sup.1CH.sub.2OCH.sub.2OCH.sub.2CH.sub.2CH═CH(CH.sub.2).sub.aCH(OR.sup.2)(OR.sup.3)   (1)
wherein R.sup.1 represents a hydrogen atom, an n-alkyl group having 1 to 9 carbon atoms, or a phenyl group, R.sup.2 and R.sup.3 represent, independently of each other, a monovalent hydrocarbon group having 1 to 15 carbon atoms, or R.sup.2 and R.sup.3 may form together a divalent hydrocarbon group, R.sup.2-R.sup.3, having 2 to 10 carbon atoms, and “a” is as defined above.

The present invention provide for preparing a formylalkenyl alkoxymethyl ether compound of the following general formula (2): R.sup.3CH.sub.2OCH.sub.2O(CH.sub.2).sub.aCH═CHCHO (2), wherein R.sup.3 represents a hydrogen atom, an n-alkyl group having 1 to 9 carbon atoms, or a phenyl group; and “a” represents an integer of 1 to 10, the process comprising: hydrolyzing a dialkoxyalkenyl alkoxymethyl ether compound of the following general formula (1): R.sup.3CH.sub.2OCH.sub.2O(CH.sub.2).sub.aCH═CHCH(OR.sup.1)(OR.sup.2) (1), wherein 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; and R.sup.3 and “a” are as defined above, in the presence of an acid while removing an alcohol compound thus generated to form the formylalkenyl alkoxymethyl ether compound (2).

The present invention provide for preparing a formylalkenyl alkoxymethyl ether compound of the following general formula (2): R.sup.3CH.sub.2OCH.sub.2O(CH.sub.2).sub.aCH═CHCHO (2), wherein R.sup.3 represents a hydrogen atom, an n-alkyl group having 1 to 9 carbon atoms, or a phenyl group; and “a” represents an integer of 1 to 10, the process comprising: hydrolyzing a dialkoxyalkenyl alkoxymethyl ether compound of the following general formula (1): R.sup.3CH.sub.2OCH.sub.2O(CH.sub.2).sub.aCH═CHCH(OR.sup.1)(OR.sup.2) (1), wherein 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; and R.sup.3 and “a” are as defined above, in the presence of an acid while removing an alcohol compound thus generated to form the formylalkenyl alkoxymethyl ether compound (2).

The present invention provides a novel compound, (4Z,6E)-4,6-undecadienyl trimethylacetate (1). The present invention further provides a process for preparing (4Z,6E)-4,6-undecadienyl trimethylacetate (1), the process comprising subjecting a 4-halobutyl trimethylacetate compound (2) wherein X.sup.1 represents a halogen atom, to a phosphonium salt formation reaction with a phosphine compound of the following general formula (3) wherein Ar represents, independently of each other, an aryl group, to obtain a [4-(trimethylacetyloxy)butyl]triarylphosphonium halide compound (4) wherein Y represents a halogen atom, and Ar is as defined above, subjecting the [4-(trimethylacetyloxy)butyl]triarylphosphonium halide compound (4) to a deprotonation reaction in the presence of a base to obtain a reaction product mixture, and subjecting the reaction product mixture to a Wittig reaction with (2E)-2-heptenal (5) to obtain (4Z,6E)-4,6-undecadienyl trimethylacetate (1).

##STR00001##

The present invention provides a novel compound, (4Z,6E)-4,6-undecadienyl trimethylacetate (1). The present invention further provides a process for preparing (4Z,6E)-4,6-undecadienyl trimethylacetate (1), the process comprising subjecting a 4-halobutyl trimethylacetate compound (2) wherein X.sup.1 represents a halogen atom, to a phosphonium salt formation reaction with a phosphine compound of the following general formula (3) wherein Ar represents, independently of each other, an aryl group, to obtain a [4-(trimethylacetyloxy)butyl]triarylphosphonium halide compound (4) wherein Y represents a halogen atom, and Ar is as defined above, subjecting the [4-(trimethylacetyloxy)butyl]triarylphosphonium halide compound (4) to a deprotonation reaction in the presence of a base to obtain a reaction product mixture, and subjecting the reaction product mixture to a Wittig reaction with (2E)-2-heptenal (5) to obtain (4Z,6E)-4,6-undecadienyl trimethylacetate (1).

##STR00001##

A process for preparing 4-penten-2-ynal of the following formula (2):
CH.sub.2═CHC≡CCHO  (2)
the process comprising a step of hydrolyzing a 5,5-dialkoxy-1-penten-3-yne compound of the following general formula (1):
CH.sub.2═CHC≡CCH(OR.sup.1)(OR.sup.2)  (1)
wherein R.sup.1 and R.sup.2 represent, independently of each other, a monovalent hydrocarbon group having 1 to 15 carbon atoms, preferably 1 to 8, more preferably 1 to 4, or R.sup.1 and R.sup.2 may be bonded to each other to form a divalent hydrocarbon group, R.sup.1-R.sup.2, having from 2 to 10 carbon atoms,
to obtain 4-penten-2-ynal (2). ##STR00001##

A process for preparing 4-penten-2-ynal of the following formula (2):
CH.sub.2═CHC≡CCHO  (2)
the process comprising a step of hydrolyzing a 5,5-dialkoxy-1-penten-3-yne compound of the following general formula (1):
CH.sub.2═CHC≡CCH(OR.sup.1)(OR.sup.2)  (1)
wherein R.sup.1 and R.sup.2 represent, independently of each other, a monovalent hydrocarbon group having 1 to 15 carbon atoms, preferably 1 to 8, more preferably 1 to 4, or R.sup.1 and R.sup.2 may be bonded to each other to form a divalent hydrocarbon group, R.sup.1-R.sup.2, having from 2 to 10 carbon atoms,
to obtain 4-penten-2-ynal (2). ##STR00001##

The present invention provide for preparing a formylalkenyl alkoxymethyl ether compound of the following general formula (2): R.sup.3CH.sub.2OCH.sub.2O(CH.sub.2).sub.aCH═CHCHO (2), wherein R.sup.3 represents a hydrogen atom, an n-alkyl group having 1 to 9 carbon atoms, or a phenyl group; and “a” represents an integer of 1 to 10, the process comprising: hydrolyzing a dialkoxyalkenyl alkoxymethyl ether compound of the following general formula (1): R.sup.3CH.sub.2OCH.sub.2O(CH.sub.2).sub.aCH═CHCH(OR.sup.1)(OR.sup.2) (1), wherein 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; and R.sup.3 and “a” are as defined above, in the presence of an acid while removing an alcohol compound thus generated to form the formylalkenyl alkoxymethyl ether compound (2).