A new enantioselective route to kainoids: application to the formal synthesis of (–)-α-kainic acid
作者:Achille Barco、Simonetta Benetti、Gian P. Pollini、Giampiero Spalluto、Vinicio Zanirato
DOI:10.1039/c39910000390
日期:——
The enantioselective synthesis of a 2,3,4-trisubstituted pyrrolidine featuring the kainoid C-2, C-3 trans, C-3, C-4 cis arrangement of substituents has been accomplished through a tandem Michael reaction strategy involving 2-nitro-3-methylbuta-1,3-diene as electrophilic alkene, the removable electron-withdrawing group acting as a template for control of the stereochemistry of the cyclization, together with a secondary benzylamine incorporating a chiral centre at the carbon bearing the nitrogen nucleophile and an appropriate α,β-unsaturated acceptor able to trap the initially formed nitronate.
通过以 2-硝基-3-甲基丁-1,3-二烯为亲电烯烃的串联迈克尔反应策略,完成了一种 2,3,4-三取代吡咯烷的对映选择性合成,该吡咯烷具有凯氏 C-2、C-3 反式、C-3、C-4 顺式排列的取代基、可拆卸的抽电子基团可作为控制环化立体化学的模板,再加上在含氮亲核碳上含有手性中心的仲苄胺和能够捕获最初形成的硝酸酯的δ,δ-不饱和受体。