Asymmetric Synthesis of the Protoberberine Alkaloid (<i>S</i>)-(−)-Xylopinine Using Enantiopure Sulfinimines
作者:Franklin A. Davis、Pradyumna K. Mohanty
DOI:10.1021/jo010988v
日期:2002.2.1
enantioselective synthesis of (S)-(-)-xylopinine (1) is described involving the addition of the laterally lithiated derivative of o-tolunitrile of 16 to enantiopure sulfinimine (+)-14. Treatment of the resulting cyano sulfinamide adduct (-)-17b with DIBAL-H accomplishes five operations in a single pot and furnishes the cyclic imine (+)-18 in good yield. Reduction and cyclization affords (S)-(-)-1. Alternatively
描述了(S)-(-)-草氨吡啶(1)的简明对映选择性合成,该方法涉及在对映纯的亚氨嘧啶(+)-14中添加邻甲苯二异氰酸酯16的侧锂基化衍生物。用DIBAL-H处理所得的氰基亚磺酰胺加合物(-)-17b,可在一个罐中完成五次操作,并以良好的收率得到环状亚胺(+)-18。还原和环化得到(S)-(-)-1。或者,17b,c的碱性水解得到异喹诺酮21,其被环化并还原成(S)-(-)-1。