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