Replacement of carcinogenic alkylating agent ethylene oxide in the synthesis of (Z)-3-dodecen-1-YL (E)-2-butenoate,sex pheromone of sweet-potato weevil,Cylas formicarius elegantulus (summers) andCylas formicarius formicarius (F.)

An alternative synthesis of (Z)-3-dodecen-1-y1 (E)-2-butenoate without use of carcinogenic ethylene oxide and HMPA is described. By coupling of the tetrahydropyranyl (THP) ether of 3-butyn-1-ol with 1-bromooctane with sodamide in liquid ammonia, 12-(2-tetrahydropyranyloxy)-9-dodecyne was obtained; subsequent hydrolysis and semihydrogenation afforded (Z)-3-dodecen-1-ol. The alcohol was then reacted with crotonyl chloride to give the desired crotonate with a total yield of 29.8%. Males of sweet-potato weevil,Cylas formicarius were strongly attracted to the synthetic sex pheromone. The attraction from the dispenser of polyethylene tube was better than the attraction from the dispenser of rubber septum in the field.