A total synthesis of (±)-cedrol and (±)-cedrene via an intramolecular Diels–Alder reaction

Abstract

A total synthesis of racemic cedrol and cedrene is described in which a key step is the intramolecular Diels–Alder reaction of alkyl cyclopentadiene 3 to give the tricyclic olefin 4. Oxidation of this material followed by ring expansion gives cedrone (6) which is converted to the sesquiterpenes. Modification of the functionality of the starting materials will permit the application of this general route to diverse tricyclic systems.