A Simple Total Synthesis of (±)-δ-Cadinene

Abstract

This paper reports on a total synthesis of racemic δ-cadinene (2), which had been obtained previously in optically active form by acid-catalyzed cyclization of (-)-germacrene D. The Robinson annelation using cyclohexenone enamine (12) proceeded stereoselectively to form δ-cadinenone (3), whose oxygen was removed by the thioketal-Raney Ni method to produce δ-cadinene.