Asymmetric Michael addition reactions using ethyl (S)-4,4-dimethylpyroglutamate as a chiral auxiliary
作者:Jesús Ezquerra、Lourdes Prieto、Carmen Avendaño、José Luis Martos、Elena de la Cuesta
DOI:10.1016/s0040-4039(98)02648-3
日期:1999.2
Ethyl 4,4-dimethylpyroglutamate has been used as a chiral auxiliary for α,β-unsaturated acids in Michael addition reactions. The conjugate addition of Grignard reagents to the amides in the presence of copper iodide, tetramethylene diamine (TMEDA) and trimethylsilyl chloride, proceeded with high yields and excellent stereoselectivities, yielding after hydrolysis enantiomerically pure β-substituted
4,4-二甲基焦谷氨酸乙酯已被用作迈克尔加成反应中α,β-不饱和酸的手性助剂。在碘化铜,四亚甲基二胺(TMEDA)和三甲基甲硅烷基氯的存在下,将格氏试剂共轭添加到酰胺中,具有高收率和出色的立体选择性,水解后得到对映体纯的β-取代的羧酸衍生物。