[摘要]：The rearrangement of a substituted cyclohexyl radical to a cyclopentylmethyl radical on the skeleton of avermectin B1 was obsd. exptl. and explored computationally. The Stork-Nishiyama methodol. was applied to the macrocycle of interest followed by a Tamao oxidn. The expected 5-6 fused ring product was obsd. in minor amts. The major product was a 5-5 fused ring resulting from apparent conversion of the initially formed cyclohexyl radical to a cyclopentylmethyl radical. Preliminary computational results indicate that substituents in the macrocycle induce the rearrangement.
