Synthesis and anti-juvenile hormone activity of 1-substituted - 5-[(E)-2,6-dimethyl-1,5-heptadienyl]imidazoles

Abstract

A new series of l-substituted-5-[(E)-2,6-dimethyl-l,5-heptadienyl]imidazoles were prepared and bioassayed for anti-juvenile hormone activity on the silkworm, Bombyx mori. The compounds induced unequivocal precocious metamorphosis in the 3rd and 4th instar larvae by topical application. Of the compounds tested, l-benzyl-5-[(E)-2,6-dimethyl- 1,5-heptadienyl] imidazole (KK-42) proved to be the most active compound eliciting 100% of precocious pupation at 2/tg/larva on the 4th instar larvae. The E isomer showed considerably higher activity than the corresponding Z isomer. The anti-juvenile hormone effect of KK-42 was counteracted by simultaneous application of JH I or methoprene. © Agricultural Chemical Society of Japan.