Total synthesis of eudesmol via an intramolecular diels-alder reaction

Abstract

The naturally occuring sesquiterpene known as eudesmol has been synthesized from R-(+)-limonene in ten steps using intramolecular Diels-Alder reaction as a key step. Tetraene was prepared from R-(+)-limonene in five steps, by a sequence of epoxidation, hydrolysis, oxidative cleavage, and two consecutive Wittig reactions. Octalin, a product of intramolecular Diels-Alder reaction of tetraene, could be converted to $\alpha$-, or $\beta$-eudesmol by a series of reactions; epoxidation, reduction, oxidation, followed by Shapiro or Wittig reaction. ##