An intramolecular Michael reaction of 9 stereoselectively gave the tricyclic compound (10), which was converted to (±)-protoemetinol (2) and 13. Compound 13 is an important intermediate for the synthesis of (±)-emetine. A simpler preparation of 13 was also carried out by the intramolecular Michael reaction of 14, followed by reduction of the ketone moietv. Furthermore, the stereoselective formation of 26, which is an intermediate for the synthesis of (±)-emetine, was achieved by the floowing sequence of reactions : intramolecular Michael reaction, of the ketone moiety, and removal of the N-carbomethoxy group.
9 的分子内迈克尔反应立体选择性地生成了
三环化合物 (10),然后转化为 (±)-protoemetinol (2) 和 13。化合物 13 是合成(±)-美丁的重要中间体。通过 14 的分子内迈克尔反应,然后还原酮莫埃特 v,也可以更简单地制备 13。此外,通过以下反应顺序:分子内迈克尔反应、酮基反应和去除 N-甲酰甲氧基反应,立体选择性地生成了 26,它是合成(±)-
甜菜碱的中间体。