Diastereomerically pure pyrrolidin-2-ones by intramolecular Michael reaction. Synthesis of both (S)- and (R)-3-pyrrolidineacetic acid
作者:Roberta Galeazzi、Geremia Silvano、Mobbili Giovanna、Orena Mario
DOI:10.1016/0957-4166(95)00423-8
日期:1996.1
By intramolecular conjugate addition of their derived enolates, the amides 5 and 6 gave diastereomeric mixtures of pyrrolidin-2-ones 10,11 and 12,13, in good yield and 80:20 d.r. After chromatographic separation, the configuration of pure diastereomers was assigned from H-1 NMR data. The usefulness of this intramolecular cyclisation was proven by conversion of either 10 or 12 into pyrrolidin-2-one 14 which through simple steps gave (S)-3-pyrrolidineacetic acid, 2. Following the same synthetic scheme, but starting from either 11 or 13, (R)-3-pyrrolidineacetic acid 3 was obtained.