Synthesis of Enantiopure 3-Substituted Pyrroline <i>N</i>-Oxides by Highly Regioselective Oxidation of the Parent Hydroxylamines: A Mechanistic Rationale
作者:Andrea Goti、Stefano Cicchi、Valentina Fedi、Luca Nannelli、Alberto Brandi
DOI:10.1021/jo962372p
日期:1997.5.1
The syntheses of four new, differently O-substituted 3-hydroxypyrroline N-oxides and the first 3-amino analogue have been performed by the use of a strategy involving double nucleophilic displacement of the corresponding dimesylates by hydroxylamine and oxidation of the resulting 1-hydroxypyrrolidines. The regioselectivity data of the oxidation reactions nicely confirm the mechanistic hypothesis, which
四种新的,不同的O取代的3-羟基吡咯啉N-氧化物和第一个3-氨基类似物的合成已通过使用一种策略进行,该策略涉及通过羟胺对相应的二甲基酯进行双亲核置换并氧化所得的1-羟基吡咯烷酮。氧化反应的区域选择性数据很好地证实了机理假说,这解释了对取代基电子性质的依赖性。区域选择性比的趋势具有有用的预测价值。通过用苯甲酰氧基官能团取代已经获得了实际的完全区域选择。O-烯丙基取代的硝酮在反应条件下不稳定,