The present invention relates to new types of processes for the improved preparation of homofarnesol, in particular of (3E,7E)-homofarnesol and homofarnesol preparations with an increased content of (3E,7E)-homofarnesol (also referred to as all E-homofarnesol).

The present invention relates to new types of processes for the improved preparation of homofarnesol, in particular of (3E,7E)-homofarnesol and homofarnesol preparations with an increased content of (3E,7E)-homofarnesol (also referred to as all E-homofarnesol).

The present invention relates to a method for the chemical conversion of an unsaturated fatty acid, particularly a carbon chain extension reaction. According to the present invention, a method for extending the length of a carbon chain in an unsaturated fatty acid by two carbon atoms is provided, said method comprising a step of heating a malonic acid ester derivative of an unsaturated fatty acid to reflux in a lower fatty acid solution in the presence of an antioxidative agent. It is preferred that the unsaturated fatty acid is an unsaturated fatty acid having 16 to 24 carbon atoms. It is preferred that the unsaturated fatty acid is selected from the group consisting of linoleic acid, linolenic acid, arachidonic acid, stearidonic acid, icosatetraenoic acid, icosapentaenoic acid, tetracosahexaenoic acid and docosahexaenoic acid. According to the method of the present invention, a carbon chain extension reaction can be completed within a shorter time.

The present invention relates to a method for the chemical conversion of an unsaturated fatty acid, particularly a carbon chain extension reaction. According to the present invention, a method for extending the length of a carbon chain in an unsaturated fatty acid by two carbon atoms is provided, said method comprising a step of heating a malonic acid ester derivative of an unsaturated fatty acid to reflux in a lower fatty acid solution in the presence of an antioxidative agent. It is preferred that the unsaturated fatty acid is an unsaturated fatty acid having 16 to 24 carbon atoms. It is preferred that the unsaturated fatty acid is selected from the group consisting of linoleic acid, linolenic acid, arachidonic acid, stearidonic acid, icosatetraenoic acid, icosapentaenoic acid, tetracosahexaenoic acid and docosahexaenoic acid. According to the method of the present invention, a carbon chain extension reaction can be completed within a shorter time.

The present invention relates to new types of processes for the improved preparation of homofarnesol, in particular of (3E,7E)-homofarnesol and homofarnesol preparations with an increased content of (3E,7E)-homofarnesol (also referred to as all E-homofarnesol).

The present invention relates to new types of processes for the improved preparation of homofarnesol, in particular of (3E,7E)-homofarnesol and homofarnesol preparations with an increased content of (3E,7E)-homofarnesol (also referred to as all E-homofarnesol).

The present invention provides a process for preparing a 4-substituted 3-methyl-1,3-butadiene compound of the following general formula (A), wherein R represents a linear, branched, or cyclic hydrocarbon group having 1 to 20 carbon atoms and optionally having an unsaturated bond(s), the process comprising steps of subjecting a primary allylsulfone compound of the following general formula (D), wherein R represents a linear, branched, or cyclic hydrocarbon group having 1 to 20 carbon atoms and optionally having an unsaturated bond(s), X represents a halogen atom, and W represents an arenesulfonyl group, to a reductive removal of the arenesulfonyl group, W, to form a halide compound of the following general formula (B), wherein R represents a linear, branched, or cyclic hydrocarbon group having 1 to 20 carbon atoms and optionally having an unsaturated bond(s), and X represents a halogen atom; and subjecting the aforesaid halide compound (B) to an elimination reaction of a hydrogen halide, HX, to form the aforesaid 4-substituted 3-methyl-1,3-butadiene compound (A).

##STR00001##

The present invention provides a process for preparing a 4-substituted 3-methyl-1,3-butadiene compound of the following general formula (A), wherein R represents a linear, branched, or cyclic hydrocarbon group having 1 to 20 carbon atoms and optionally having an unsaturated bond(s), the process comprising steps of subjecting a primary allylsulfone compound of the following general formula (D), wherein R represents a linear, branched, or cyclic hydrocarbon group having 1 to 20 carbon atoms and optionally having an unsaturated bond(s), X represents a halogen atom, and W represents an arenesulfonyl group, to a reductive removal of the arenesulfonyl group, W, to form a halide compound of the following general formula (B), wherein R represents a linear, branched, or cyclic hydrocarbon group having 1 to 20 carbon atoms and optionally having an unsaturated bond(s), and X represents a halogen atom; and subjecting the aforesaid halide compound (B) to an elimination reaction of a hydrogen halide, HX, to form the aforesaid 4-substituted 3-methyl-1,3-butadiene compound (A).

##STR00001##

The present invention provides a process for preparing a 2-(3-alkenyl)-1,3-butadiene compound of the following general formula (A), wherein R.sup.1 and R.sup.2 represent, independently of each other, a hydrogen atom or a linear, branched, or cyclic hydrocarbon group having 1 to 20 carbon atoms and optionally having an unsaturated bond(s), the process comprising the step of subjecting a secondary allylsulfone compound of the following general formula (G), wherein R.sup.1 and R.sup.2 represent, independently of each other, a hydrogen atom or a linear, branched, or cyclic hydrocarbon group having 1 to 20 carbon atoms and optionally having an unsaturated bond(s), W represents an arenesulfonyl group, and Z represents a halogen atom, to a reductive removal of an arenesulfonyl group, W, at an allyl position, and then subjecting the secondary allylsulfone compound (G) to an elimination reaction of a hydrogen halide, HZ, in this order or in reverse order, to form the 2-(3-alkenyl)-1,3-butadiene compound (A).

##STR00001##

The present invention provides a process for preparing a 2-(3-alkenyl)-1,3-butadiene compound of the following general formula (A), wherein R.sup.1 and R.sup.2 represent, independently of each other, a hydrogen atom or a linear, branched, or cyclic hydrocarbon group having 1 to 20 carbon atoms and optionally having an unsaturated bond(s), the process comprising the step of subjecting a secondary allylsulfone compound of the following general formula (G), wherein R.sup.1 and R.sup.2 represent, independently of each other, a hydrogen atom or a linear, branched, or cyclic hydrocarbon group having 1 to 20 carbon atoms and optionally having an unsaturated bond(s), W represents an arenesulfonyl group, and Z represents a halogen atom, to a reductive removal of an arenesulfonyl group, W, at an allyl position, and then subjecting the secondary allylsulfone compound (G) to an elimination reaction of a hydrogen halide, HZ, in this order or in reverse order, to form the 2-(3-alkenyl)-1,3-butadiene compound (A).

##STR00001##