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).
(-)-eserethole (2) 的全合成已经完成,其中关键步骤是利用(S)-(-)-2-甲基-2-[2-(E)-
硝基乙烯基]-
δ-戊内酯(3)与Danishefsky's二烯的Diels-Alder反应。光学纯(-)-eserethole (2)的合成构成了卡拉
巴豆生物碱如(-)-physostigmine (1)、(-)-physovenine (17)和(-)-geneserine (18)的形式合成。