Abstract
A total synthesis of (-)-eserethole (2) has been accomplished using the Diels-Alder reaction of (S)-(-)-2-methyl-2-[2-(E)-nitroethenyl]-δ-valerolactone (3) and Danishefsky's diene as a key step. The synthesis of optically pure (-)-eserethole (2) constitutes a formal synthesis of naturaly occurring Calabar bean alkaloids, such as (-)-physostigmine (1), (-)-physovenine (17) and (-)-geneserine (18).