4-benzyl-2,3-didehydroprolinate as a homochiral template for michael additions. Synthesis of enantiopure α-allokainoids, β-kainoids, 2,3-methanoprolines and other 3,4-disubstituted prolines
作者:Jesús Ezquerra、Ana Escribano、Almudena Rubio、Modesto Jesús Remuiñán、Juan José Vaquero
DOI:10.1016/0957-4166(96)00336-9
日期:1996.9
Ethyl (4R)-N-methoxycarbonyl-4-benzyl-2,3-didehydroprolinate10a undergoes Michael additions with stabilized carbanions and cuprates giving exclusively the enantiopure all-trans 3,4-disubstituted prolinates. The high stereoselection observed in this reaction is driven by the C-4 substituent of the Michael acceptor. This methodology has been applied to the synthesis of the enantiopure β-kainoid 5a and
乙基(4 - [R )- ñ甲氧基羰基-4-苄基-2,3- didehydroprolinate 10A经历Michael加成具有稳定的负碳离子和铜酸盐给予专门的对映体纯清一色反式3,4-二取代prolinates。在该反应中观察到的高立体选择是由迈克尔受体的C-4取代基驱动的。该方法学已被用于对映体纯β-类卡因醇5a和2,3-methanoproline 15的合成。