A convenient approach to diastereomerically pure 1,3,4-trisubstituted pyrrolidin-2-ones by intramolecular cyclisation of N-(2-alken-1-yl)amides mediated by Mn(III). An entry to both (R)- and (S)-3-pyrrolidineacetic acid
作者:Roberta Galeazzi、Giovanna Mobbili、Mario Orena
DOI:10.1016/0040-4020(95)00939-6
日期:1996.1
The oxidative cyclisation of a series of either (S)-N-(2-alken-1-yl)-N-(1-phenyleth-1-yl)-acetoacetamides5a-d and methoxycarbonylacetamides 6a-b, performed by using Mn(OAc)3 · 2H2) and Cu(OAc)2 · H2O in acetic acid, has been examined. The reaction proceeds regioselectively through a 5-exo-mode, leading to 1,3,4-trisubstituted pyrrolidin-2-ones 7a-d,8a-d and 9a-b,10a-b as diastereomeric mixtures in
使用Mn进行的一系列(S)-N-(2-烯-1-基)-N-(1-苯基乙基-1-基)-乙酰乙酰胺5a-d和甲氧羰基乙酰胺6a-b的氧化环化反应(OAc)3 ·2H 2)和Cu(OAc)2 ·H 2 O在乙酸中的含量已经过检验。该反应通过5- exo-模式区域选择性地进行,得到1,3,4-三取代的吡咯烷酮-2-酮7a-d,8a-d和9a-b,10a-b以约2:1的比例的非对映体混合物形式存在,其容易通过硅胶色谱法分离。由1 H NMR数据确定纯的非对映异构体的构型,并通过NOE实验确认。在分子力学计算的基础上解释了观察到的不对称感应。该环化构成了用于合成对映体纯形式(例如(R)-和(S)-3-吡咯烷乙酸)1和2均含有吡咯烷环的生物活性氨基酸的有用工具。