Synthesis of milbemycins alpha9, alpha10, alpha11, alpha12, alpha14, alpha15, alpha20, alpha21, alpha22, alpha23, alpha26, alpha27, delta(2,3),delta(4,26)-milbemycins A3, A4 from milbemycins A3, A4, and their acaricidal activities

Chemical derivation methods to prepare 26-acyloxy and 26-hydroxymilbemycins, which had been reported as natural products, milbemycins alpha9, alpha10, alpha11, alpha12, alpha14, alpha15, alpha20, alpha21, alpha22, alpha23, alpha26, alpha27 from milbemycins A3, A4 were reported. Delta(2,3),delta(4,26)-milbemycins A3, A4, which had also been reported as natural products, were further prepared from milbemycins A3, A4. Their acaricidal activities were also assessed against the organophosphorus-sensitive two-spotted spider mite (Tetranychus urticae) on primary leaves of cowpea plants (Vigna sinesis Savi species) by spraying.