A One-Pot Formal [4 + 2] Cycloaddition Approach to Substituted Piperidines, Indolizidines, and Quinolizidines. Total Synthesis of Indolizidine (−)-209I
作者:Shanghai Yu、Wei Zhu、Dawei Ma
DOI:10.1021/jo051080y
日期:2005.9.1
delivers substituted piperidines in good yields. This transformation goes through a cascade Michael addition/alkylation process and represents a facile one-pot formal [4 + 2] cycloaddition approach to piperidine ring. Using secondary cyclic γ-chloropropylamines as substrates, this process produces substituted indolizidines or quinolizidines. On the basis of this approach, indolizidine (−)-209I is elaborated
在70-83°C下加热i -PrOH中取代的N-苄基γ-氯丙胺,共轭炔酸或炔酮,碳酸钠和催化量的碘化钠的混合物,可得到高产率的取代哌啶。该转化经历级联的迈克尔加成/烷基化过程,代表对哌啶环的简便的一锅形式[4 + 2]环加成方法。使用仲环状γ-氯丙胺作为底物,该方法产生取代的吲哚并咪唑或喹唑烷。在此方法的基础上,由11个步骤从2-己酸甲酯精制了吲哚唑烷(-)-209I。