Synthesis of Ring B-Rearranged Taxane Analogs

Abstract

Reaction of the C-7 hydroryl group on the 9-dihydrotaxane skeleton with triflic anhydride causes a major skeletal rearrangement to occur leading to contraction of ring B. In addition the formation of a ring C-fused cyclopropane structure occurs. The requisite C-13 phenylisoserinate side chins are appended via an initial deacylation of the C-13 acetate followed by reacylation and deprotection. These rearranged compounds show very similar structural features with the parent 9-dihydrotaxane skeleton and also retain biological activity