Sequential One-Pot Cyclizations: Concise Access to the ABCE Tetracyclic Framework of <i>Strychnos</i> Alkaloids
作者:Gopal Sirasani、Rodrigo B. Andrade
DOI:10.1021/ol9004799
日期:2009.5.21
A sequential one-pot biscyclization route to the ABCE tetracyclic framework of Strychnos alkaloids has been developed. Specifically, the AgOTf-mediated spirocyclization of an appropriately functionalized indole 3-carbinamide afforded a stable spiroindolenine intermediate; subsequent addition of DBU to the reaction mixture effected an unprecedented intramolecular aza-Baylis−Hillman reaction, delivering
到的ABCE四环框架的一个连续一锅biscyclization路线马钱子生物碱已经研制成功。具体地,通过AgOTf介导的适当官能化的吲哚3-碳酰胺的螺环化提供了稳定的螺环吲哚中间体。随后向反应混合物中添加DBU进行了前所未有的分子内aza-Baylis-Hillman反应,以70%的分离产率提供了四环产物。