reaction, and an imine reduction/intramolecular aminolysis process. To address the epimerization issue during Schmidt reaction, an improved synthesis was developed, which also led to a synthesis of 22-epi-solanidine. In this synthesis, selective transformation of azido lactone to azido diol and amino diol was realized through a reduction relay tactic. The azido diol was transformed to solanidine via
描述了由25 R-配置的薯os
皂苷元
乙酸酯合成茄碱和22-表-茄
嘌呤,两种25 S天然甾体
生物碱的发散性合成。最初,茄碱是通过一系列转化合成的,包括
呋喃斯坦26-酸的级联环转换过程,受六元内酯环构象控制的C25差向异构化,分子内Schmidt反应以及
亚胺还原/分子内
氨解过程。为了解决施密特反应过程中的差向异构问题,开发了一种改进的合成方法,该方法还导致合成22-表位异构体-
茄啶。在该合成中,通过还原中继策略实现了
叠氮基内酯选择性转化为
叠氮基二醇和
氨基二醇。
叠氮基二醇通过分子内Schmidt反应/ N-烷基化/还原过程被转化为
茄啶,并且通过分子内双N-烷基化过程被转化为22-外延-
茄啶。