Enantiopure alkaloid analogues and iminosugars from proline derivatives: stereocontrol in sequential processes
作者:Alicia Boto、Dácil Hernández、Rosendo Hernández
DOI:10.1016/j.tetlet.2009.04.082
日期:2009.7
use of expensive auxiliaries or catalysts in the synthesis of chiral 2-substituted pyrrolidines is described. Thus, commercial, cheap 4-(S)-hydroxyproline was readily transformed into optically pure pyrrolidines, using a one-pot decarboxylation–alkylation reaction as the key step. In this reaction, an acyliminium intermediate was generated, which was trapped by carbon nucleophiles. As postulated by
描述了在合成手性2-取代的吡咯烷中使用昂贵的助剂或催化剂的替代方法。因此,使用一锅脱羧-烷基化反应作为关键步骤,可将廉价的商用4-(S)-羟基脯氨酸轻松转化为光学纯的吡咯烷。在该反应中,生成了一个酰基酰亚胺中间体,该中间体被碳亲核试剂捕获。如Woerpel所假定的,亲核试剂是立体选择性地加到五元环亚胺离子上的,从而以高纯度得到2,4-顺式二取代的吡咯烷。然后可以除去C-4处的羟基,或者可以将其用于在分子中创建新的官能团。以此方式,制备了光学纯的生物碱类似物和亚氨基糖。