Diastereodivergent Synthesis of 4-Hydroxy-2,3-methanopipecolic Acid Derivatives as Conformationally Constrained Homoserine Analogues
作者:Ernesto G. Occhiato、Andrea Casini、Antonio Guarna、Dina Scarpi
DOI:10.1002/ejoc.201100962
日期:2011.11
methylide were 1:4 to 1:7 in DMSO and diastereopure trans isomers were obtained by chromatography after OH-deprotection in 57–73 % yield. These compounds are new, conformationally constrained homoserine analogues potentially useful as conformational probes and for drug discovery in medicinal chemistry.
报告了一种用于非对映发散合成具有高光学纯度的环丙烷化 4-羟基哌啶酸衍生物的简短实用程序。关键步骤是高度对映选择性脂肪酶催化的动力学拆分和 4-羟基吡啶衍生物的立体选择性环丙烷化反应。在 OH 导向的环丙烷化的最佳条件下,Charette 的 Zn-carbenoid 以最高产率 (73–86%) 和面部选择性 (> 99:1) 提供顺式-4-羟基-2,3-甲氧基哌啶酸。DMSO 中二甲基亚砜的迈克尔型加成反应的反式选择性为 1:4 至 1:7,非对映纯反式异构体在 OH 脱保护后通过色谱法获得,产率为 57-73%。这些化合物是新的,