An easy access to bioactive 13-hydroxylated and 11,13-dihydroxylated sesquiterpene lactones (SLs) through Michael addition of a nucleophilic hydroxyl group
作者:Francisco A. Macías、María D. García-Díaz、Guillermo M. Massanet、José F. Gómez-Madero、Frank R. Fronczek、Juan C.G. Galindo
DOI:10.1016/j.tet.2008.09.024
日期:2008.12
The addition of a hydroxyl group to α,β-unsaturated carbonyl systems provides a new and easy access to bioactive difunctionalized sesquiterpene lactones (SLs) through a Michael addition to the α-methylene-γ-lactone system. The use of HMPA to enhance the nucleophilic properties of the hydroxyl groups and to stabilize the enolate is discussed. Also, we present a proposal for the mechanism based on the
通过在α-亚甲基-γ-内酯系统中加成迈克尔基,向α,β-不饱和羰基系统中添加羟基可轻松获得新的生物活性双官能倍半萜烯内酯(SLs)。讨论了使用HMPA增强羟基的亲核性质并稳定烯醇化物。另外,我们根据获得的实验数据提出了该机制的建议。该反应的范围和有用性与其他底物一起探索,并受到对一定水平位阻以避免链缩聚的需求的限制。然而,该反应可与酯,酮和醛一起使用。通过X射线衍射分析已经阐明了某些产物的绝对立体化学。