Facile and efficient syntheses of (3Z,6Z,9Z)-3,6,9-nonadecatriene and homologues: pheromone and attractant components of lepidoptera.

Facile and efficient chemical syntheses of (3Z,6Z,9Z)-3,6,9-nonadecatriene and homologues from commercially available alpha-linolenic acid [(9Z,12Z,15Z)-9,12,15-octadecatrienoic acid] are reported. These straight-chain homoconjugated trienes are common sex pheromone and attractant components for many lepidopterous insect pests. The metal-catalyzed cross-coupling reactions between (9Z,12Z,15Z)-9,12,15-octadecatrienyl triflate and the appropriate Grignard reagents proceed very rapidly under notable mild conditions using Li(2)CuCl(4) as catalyst in diethyl ether, and the resulting (3Z,6Z,9Z)-3,6,9-trienes with retention of geometrical configuration were in >92% isolated yield.