An Efficient and Enantioselective Approach to the Azaspirocyclic Core of Alkaloids: Formal Synthesis of Halichlorine and Pinnaic Acid
作者:Hong-Lu Zhang、Gang Zhao、Yu Ding、Bin Wu
DOI:10.1021/jo047882v
日期:2005.6.1
A novel, highly stereoselective synthesis of an azaspirocyclic core, which contains four stereogenic carbons consistent with structures of natural halichlorine and pinnaic acid, is presented. Lipase PS-catalyzed selective acylation, asymmetric methylation on the α-methylene of the bicyclic lactone, and an asymmetric Michael addition of the tertiary nitro cyclopentane were concisely used to conquer