Stereocontrolled Total Synthesis of (−)-Kainic Acid. Regio- and Stereoselective Lithiation of Pyrrolidine Ring with the (+)-Sparteine Surrogate
作者:Yasuhiro Morita、Hidetoshi Tokuyama、Tohru Fukuyama
DOI:10.1021/ol051408+
日期:2005.9.1
[reaction: see text] A stereocontrolled total synthesis of (-)-kainic acid is described. cis-3,4-Disubstituted pyrrolidine ring was constructed by [3 + 2] cycloaddition of azomethine ylide with chiral butenolide. The crucial introduction of carboxyl group at the C-2 position was executed by regio- and stereoselective lithiation of the pyrrolidine ring in the presence of a (+)-sparteine surrogate followed
[反应:见正文]描述了立体控制的(-)-海藻酸的全合成。顺式-3,4-二取代的吡咯烷环是通过偶氮甲酰内酯与手性丁烯内酯的[3 + 2]环加成而构建的。在(+)-天冬氨酸替代物的存在下,通过吡咯烷环的区域和立体选择性锂化来实现C-2位羧基的关键引入,然后用二氧化碳捕集。