Synthesis of (±)-disparlure.

A six-step, convergent synthesis has been developed for racemic (Z)-7,8-epoxy-2-methyloctadecane (disparlure), the sex pheromone of the gypsy moth. The key step is a Wittig reaction between 6-methylheptanal and triphenylundecylphosphonium bromide effected by potassium carbonate in the presence of a crown ether.