An Efficient Enantioselective Synthesis of (+)-Disparlure

Abstract

Synthesis of (+)-disparlure, 1, the sex pheromone of gypsy moth (Lymantria dispar), commenced from cis-vinyl epoxide 4 which was prepared by our asymmetric chloroallylboration in 99% de and 94% ee. Hydroboration of 4 using dicyclohexylborane in THF, followed by sodium perborate oxidation gave a crystalline cis-3,4-epoxy alcohol 3 whose enantiomeric purity was enhanced by recrystallization. Conversion of 3 to (+)-disparlure was via alkylation of the tosylate. (+)-Disparlure was produced in four steps with an overall yield of 27% and >/=99.5% ee.