Total synthesis of (.+-.)-carpesiolin.

Abstract

Total synthesis of (±)-carpesiolin (1) is described using a new and general synthetic route to helenanolide sesquiterpenes. The scheme includes the stereocontrolled introduction of the C-10 α-methyl group in the perhydroindanone (3) and its conversion to the perhydroazulenone (4) via the regiospecific ring expansion reaction.