Concise Total Syntheses of Variecolortides A and B through an Unusual Hetero‐Diels–Alder Reaction

Abstract

A fusion of certain anthraquinones and diketopiperazines is an apt description of the variecolortides, a family of unusual fungal alkaloids. In a new, concise total synthesis of the variecolortides A and B, the natural racemates are obtained highly convergently and almost without protecting-group manipulations. The spirocyclic core is generated in a hetero-Diels–Alder reaction of a 1,4-anthraquinone with a didehydrodiketopiperazine.