trisubstituted piperidine moiety via condensation of a beta-keto sulfone with an l-alanine-derived bromide and subsequent alkylative cyclization and construction of its quinolizidine skeleton via a diastereoselective intramolecular conjugate addition. The possible stereochemical course for this conjugate addition is discussed.
[结构:见正文]描述了一条组装克拉维汀类化合物A和B和哌替明的短途路线,该路线的特征是通过将β-
酮砜与
L-丙氨酸衍生的
溴化物缩合,随后烷基化环化和构建来精制其三取代
哌啶部分。通过非对映选择性分子内共轭物的添加来合成其
喹喔啉骨架。讨论了该共轭物添加的可能的立体
化学过程。