Enantioselective Highly Efficient Synthesis of (−)-Cephalotaxine Using Two Palladium-Catalyzed Transformations
作者:Lutz F. Tietze、Hartmut Schirok
DOI:10.1021/ja991650+
日期:1999.11.1
Cephalotaxine (1), the major alkaloid isolated from Cephalotaxus species, has attracted considerable attention due to the promising antitumor activity of several of its derivatives and its unique structural features. Herein we describe a highlyefficient enantioselective synthesis of 1 employing two successive Pd-catalyzed transformations starting from 25 to give the pentacyclic product 6. The controlling