SYNTHESIS OF 5-DEOXY-5-OXOMILBEMYCIN A(4) 5-HYDRAZONE DERIVATIVES ANDTHEIR ACTIVITY AGAINST TETRANYCHUS-URTICAE

5-Deoxy-5-oxomilbemycin A(4) 5-hydrazone derivatives were synthesized by a condensation reaction of 5-deoxy-5-oxomilbemycin A(4) (2) with hy drazines. Acetic acid played an important role to give each hydrazone in a good yield by regulating the reactivity of ketone 2 and the hydra zines. The acaricidal activity of each synthesized compound was studie d on the primary leaves of plants of the Vigna sinensis Savi species i nfected with organic phosphate-sensitive mites (Tetranychus urticae), Some of the synthesized derivatives exhibited higher miticidal activit y than that of milbemycin A(4). Among them, 5-deoxy-5-oxomilbemycin A( 4) 5-N-(N',N'-dimethylcarbamoyl)hydrazone (18) totally controlled the mites at a concentration of 3 ppm.