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
An enantioselective total synthesis of pinnaic acid
作者:Hao Wu、Honglu Zhang、Gang Zhao
DOI:10.1016/j.tet.2007.03.031
日期:2007.7
An enantioselective and convergent total synthesis of marine natural product pinnaic acid has been achieved. Our general syntheticapproach is featured with an asymmetric hydrogenation of racemic γ-keto ester 3, a diastereoselective methylation on the α-methylene of the (1R,5R)-lactone 4, and a diastereoselective Michael addition of the tertiary nitro cyclopentane. The central azaspiro[4.5]decane was