A simple, inexpensive, step economic, and highly modular synthetic strategy to access izidine alkaloids is described. The key step is a TfOH-promoted intramolecular aldol condensation between enol and cyclic imide moieties. This cyclization strategy can be employed within an aza-Robinson annulation framework and represents a general tool to build fused bicyclic amines. To illustrate the power of this
描述了一种简单、廉价、步骤经济且高度模块化的合成策略来获取齐嗪
生物碱。关键步骤是 TfOH 促进烯醇和环状
酰亚胺部分之间的分子内羟醛缩合。这种环化策略可以在氮杂罗宾逊环化框架内采用,并且代表了构建稠合双环胺的通用工具。为了说明该方法的功效,我们描述了 (±)-coniceine、(±)-quinolizidine、(±)-tashiromine、(±)-epilupinine 和 (±)-valmerins 核心的制备。