作者:Dieter Enders、Bert Nolte、Jan Runsink
DOI:10.1016/s0957-4166(02)00133-7
日期:2002.4
Starting from a protected glycol aldehyde hydrazone a flexible asymmetric synthesis of 2-substituted piperidin-3-ols was achieved. An α-alkylation/1,2-addition sequence furnished the intermediate hydrazines which were subjected to reductive cleavage of the chiral auxiliary. After acidic workup and simultaneous deprotection the title compounds were obtained in moderate overall yields and excellent diastereomeric
从受保护的乙二醇醛开始,可以实现2-取代的哌啶-3-醇的柔性不对称合成。α-烷基化/ 1,2-加成序列提供了中间体肼,该肼经历了手性助剂的还原裂解。在酸性处理和同时脱保护后,通过在还原性胺化条件下闭环,以适中的总收率和优异的非对映异构体和对映异构体过量(de,ee > 96%)获得标题化合物。