Synthesis of disparlure and monachalure enantiomers from 2,3-butanediacetals.

2,3-Butanediacetal derivatives were used for the stereoselective synthesis of unsymmetrically substituted -epoxides. The procedure was applied for the preparation of both enantiomers of disparlure and monachalure, the components of the sex pheromones of the gypsy moth () and the nun moth () using methyl (2,3,5,6)-3-ethylsulfanylcarbonyl-5,6-dimethoxy-5,6-dimethyl-1,4-dioxane-2-carboxylate as the starting material.