Insecticidal milbemycin derivatives having a substituent containing an oxime group # 13

摘要

PURPOSE: To obtain a 13-substituted milbemycin derivative, having excellent acaricidal, insecticidal and anthelmintic activities against mites, plant insect pests or animal parasites and containing oxime group at the 13-position. ;CONSTITUTION: This derivative of formula I [R¹ is methyl, ethyl, etc.; A is a heterocyclic group or a 6-10C aryl; (m) and (n) are each independently 0 or 1], e.g. 13-(α-methoxyiminophenylacetoxy)milbemycin A₄, is obtained by reaction a 15-hydroxymilbemycin derivative of formula II with a carboxylic acid or an alcohol of the formula A¹-(C=N-OR²)-(CH₂)_m-(C=0)_n-OH in the presence of a strong acid such as sulfuric acid in a solvent such as benzene at 0-50°C for 10min to 2hr, providing a compound of formula III, then reacting the resultant compound of formula III with a reducing agent such as sodium borohydride in a solvent such as methanol at 0-50°C for 5min to 2hr and reducing the carbonyl group at the 5-position into hydroxyl group.;COPYRIGHT: (C)1996,JPO