(Z)-Hexadenes,their epoxides and arylanalogs were prepared s’tereo-specifically by Wittig reaction of alkylidenetriphenylphosphoranes with alkylaldehydes or arylaldehydes respectively.(E)-5-Hexadecene was obtained from the conversion of (Z)-5-hexadecene via addition of bromine,elimination-reduction with NaNH2/NH3 These compounds are active in EAG responses. (Z) -Hexadenes, their epoxides and arylanalogs were prepared s’tereo-specifically by Wittig reaction of alkylidenetriphenylphosphoranes with alkylaldehydes or arylaldehydes respectively. (E) -5-Hexadecene was obtained from the conversion of (Z) -5-hexadecene via addition of bromine, elimination-reduction with NaNH2 / NH3 These compounds are active in EAG responses.