(4Z,6E)-4,6-undecadienyl trimethylacetate and process for preparing (5Z,7E)-5,7-dodecadiene compound therefrom

A process for preparing (4Z,6E)-4,6-undecadienyl trimethylacetate of the following general formula (1):

• the process comprising:
• subjecting a 4-halobutyl trimethylacetate compound of the following general formula (2):
• wherein X1 represents a halogen atom,
• to a phosphonium salt formation reaction with a phosphine compound of the following general formula (3):
• PAr
• 3
• (
• 3
• )
• wherein Ar represents, independently of each other, an aryl group,
• to obtain a [4-(trimethylacetyloxy)butyl]triarylphosphonium halide compound of the following general formula (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 of the following formula (5):
• to obtain (4Z,6E)-4,6-undecadienyl trimethylacetate (1).

A process for preparing a (4Z,6E)-1-halo-4,6-undecadiene compound of the following general formula (7):

• wherein X2 represents a halogen atom,
• the process comprising:
• subjecting (4Z,6E)-4,6-undecadienyl trimethylacetate of the following general formula (1):
• to de-trimethylacetylation to obtain (4Z,6E)-4,6-undecadien-1-ol of the following formula (6):
• and
• halogenating (4Z,6E)-4,6-undecadien-1-ol (6) to form the (4Z,6E)-1-halo-4,6-undecadiene compound (7).