Chapter 28. The Intramolecular Diels-Alder Reaction in Organic Synthesis

Abstract

Publisher Summary This chapter discusses the importance of intramolecular Diels–Alder reaction in organic synthesis. The [4+2]cycloaddition reaction long known to organic chemists as the Diels–Alder reaction is among the most powerful of the many synthetic tools for the synthesis of complex organic molecules. Its ability to produce with high stereoselectivity, good yield, and in a predictable manner a single stereoisomer containing several chiral centers is almost unique among organic reactions. Two novel synthetic approaches to the sesquiterpene seychellene have been based upon the utilization of the intramolecular Diels–Alder reaction as the key step in the generation of the tricyclic carbon skeleton. In the first approach, the strategy involved the preparation of the tricyclic intermediate by the intramolecular cyclization of the cyclohexadienone. The required cyclohexadienone was prepared in several steps as a mixture of diastereomers from 2,3-dimethylcyclohexenone and generated in situ by an amine oxide pyrolysis. The synthesis of the α- and β-himalchenes that uses an intramolecular Diels–Alder reaction as the key step in establishing the proper carbon skeleton is also elaborated in the chapter.