A Formal Enantiospecific Synthesis of 7,20‐Diisocyanoadociane

Abstract

7,20‐Diisocyanoadociane (DICA) is a potent antimalarial isocyanoterpene endowed with a fascinating tetracyclic structure composed of fused chair cyclohexanes. We report a highly stereocontrolled synthesis of a late‐stage intermediate, the “Corey dione”, from which DICA has been made previously. This formal synthesis features a rapid buildup of much of the complexity of the target through a sequence of enone tandem vicinal difunctionalization, Friedel–Crafts cyclodehydration, and sequential stereocontrolled reductions. Most importantly, this success establishes the broader feasibility of our previously developed general synthesis approach to the isocyanoterpene family and provides a blueprint for a very direct synthesis of DICA and related natural products.