Synthesis of the Himachalenes by an Intramolecular Diels-Alder Reaction Route

Abstract

Cyclization of an acyclic triene in an intramolecular Diels-Alder reaction sense constitutes a one-step production of a bicyclic olefin. Such method of synthesis should find broad acceptance in the field of organic natural products, especially in light of the high desirability of rapid acquisition of complexity of structure.² The following synthesis of α- and β-himachalene (A and B, respectively)³ illustrates an application of the scheme in the sesquiterpene area.