Several new polyhydroxylated alkaloids including pyrrolidines with a long side chain and 3-(hydroxymethyl) indolizidines were prepared from a common nitrone easily obtained from d-arabinose. In addition, a total synthesis of hyacinthacine A2 has been achieved in five steps and 67.7% overall yield starting from the same d-arabino-derived nitrone. All synthesized compounds have a common structural feature
Concise synthesis of bicyclic iminosugars <i>via</i> reductive functionalization of sugar-derived lactams and subsequent RCM reaction
作者:Piotr Szcześniak、Bartłomiej Furman
DOI:10.1039/d1ob01172c
日期:——
method for the synthesis of bicyclic iminosugars has been developed. The strategy is based on the partial reduction of sugar-derived lactams by Schwartz's reagent and tandem stereoselective nucleophile addition dictated by Woerpel's model which affords polyhydroxylated cyclic amines as key intermediates. Introduction of a vinyl or allyl group to the iminosugar produces diene derivatives that can be
开发了一种合成双环亚氨基糖的有效方法。该策略基于通过 Schwartz 试剂和串联立体选择性亲核试剂加成的糖衍生内酰胺的部分还原,由 Woerpel 模型提供多羟基化环胺作为关键中间体。将乙烯基或烯丙基基团引入亚氨基糖产生二烯衍生物,该衍生物可以进行闭环复分解反应 (RCM),以良好至极好的产率提供多羟基化吡咯里西啶、中氮茚和喹唑啉衍生物。该反应序列已应用于风信子 A 2的正式合成,它是一种多羟基化的吡咯里西啶生物碱。