Selective alkylation of diethyl 3-oxoglutarate. Part IX. Synthesis of racemates and (+)-enantiomers of .GAMMA.-caprolactone, .GAMMA.-dodecanolactone and .DELTA.-hexadecanolactone, lactonic sex pheromones of the dermestid beetle, rove beetle and Oriental hornet.

Abstract

A simple method based on regioselective two-step alkylation of easily-available diethyl 3-oxoglutarate (2) is described for the synthesis of racemates of the lactonic pheromones, la, lb, and 1c. Their (+)-enantiomers were also synthesized by means of microbiological reduction of the intermediary keto acids.