Total Synthesis of (±)‐Phyllantidine: Development and Mechanistic Evaluation of a Ring Expansion for Installation of Embedded Nitrogen‐Oxygen Bonds
作者:Kyle M. Lambert、Joshua B. Cox、Lin Liu、Amy C. Jackson、Sam Yruegas、Kenneth B. Wiberg、John L. Wood
DOI:10.1002/anie.202003829
日期:2020.6.8
The development of a concise total synthesis of (±)‐phyllantidine (1 ), a member of the securinega family of alkaloids containing an unusual oxazabicyclo[3.3.1]nonane core, is described. The synthesis employs a unique synthetic strategy featuring the ring expansion of a substituted cyclopentanone to a cyclic hydroxamic acid as a key step that allows facile installation of the embedded nitrogen‐oxygen
(±)-phyllantidine(一个简明的全合成的发展1)中,所述的构件叶底描述了一个家族的生物碱家族,它们含有不寻常的恶唑双环[3.3.1]壬烷核心。该合成采用独特的合成策略,其特征在于取代环戊酮向环状异羟肟酸的扩环是关键步骤,可轻松安装嵌入的氮-氧(N-O)键。通过计算和实验评估了实现所需区域化学结果的最佳序列及其机理基础。这种合成方法还具有早期非对映选择性醛醇缩合反应,以组装取代的环戊酮,轻度还原酰胺中间体而无N-O键断裂,以及通过使用Bestmann ylide快速组装(1)中发现的丁烯内酯。。