Synthesis of 4″-benzyloxyimino-4″-deoxyavermectin B1a derivatives

Six new 4″-benzyloxyimino-4″-deoxyavermectin B1a derivatives were synthesized from avermectin B1a by the selective protection of C-5-hydroxy group, oxidation of C-4″-hydroxy group, and deprotection followed by reaction with O-substituted hydroxylamine hydrochlorides. Their structures were confirmed by IR, 1H NMR, 13C NMR and MS. Insecticidal activities of the derivatives against Phopalosiphum pseudobrassicae, Spodoptera exigua and Pluteua xylosteua were evaluated.