A radical-based approach for the construction of the tetracyclic structure of resiniferatoxin

Abstract

A novel radical-based strategy for accessing the unique tetracyclic skeleton of resiniferatoxin is described. The synthetic route is characterized by a stereoselective synthesis of the C-ring which has a bridgehead O,Se–acetal, a three component radical coupling of the A- and C-rings and a branched allyl stannane, and a 7-endo radical cyclization to construct the fused B-ring from the coupling adduct. The present approach attests to the power of radical reactions to realize the congested C–C bond formations required for synthesizing highly functionalized compounds.