Preparation of Four Geometric Isomers of the Eri-silk Moth Pheromone, (11Z)-4, 6, 11-Hexadecatrienals, and Their Effect toward Male Eri-silk Moths

Abstract

Four geometric isomers of the eri-silk moth pheromone, (11z)-4, 6, 11-hexadecatrienals, including the natural pheromone, (4E, 6E, 11Z)-4, 6, 11-hexadecatrienal (19), were prepared and their pheromone activities toward male eri-silk moths were evaluated. In the conventional fluttering test, each of the synthesized trienal fractions showed activity, the 50% active minimum concentration of natural pheromone 19 being observed to be 10^-3 mg/ml. The pheromone activities of these geometric isomers were compared by the EAG/GLC method and found in order of increasing activity to be (4Z, 6E, 11Z)-≥(4E, 6Z, 11, Z)->(4E, 6E, 11Z)-»(4Z, 6Z, 11Z)-hexadecatrienal.