Total Syntheses of Trichorabdal A and Maoecrystal Z

Abstract

This work reports the total syntheses of Isodon diterpenes trichorabdal A and maoecrystal Z via a common bicyclo[3.2.1]octane intermediate, which chemically bridges the two distinct structures through a retro-aldol/aldol reaction cascade. Other synthetic features include an efficient cross-ring radical cyclization for rapid construction of an all carbon quaternary center commonly seen in Isodon diterpenoids, a challenging Ueno-Stork cyclization on to a sensitive 1,6-enone system, as well as a serial of chemoselective functional group manipulations in complex chemical environments.