β-Lithiated Enamines as Enolate Equivalents in Michael Additions to Enoates. A Novel Entry to Mono- and Disubstituted 5-Oxo Esters
作者:Lucette Duhamel、Pierre Duhamel、Dieter Enders、Wolfgang Karl、Frederic Leger、Jean M. Poirier、Gerhard Raabe
DOI:10.1055/s-1991-26536
日期:——
Mono-, di- and trisubstituted tert-butyl 5-amino-4-alkenoates 3 and mono- or disubstituted tert-butyl 5-oxoalkanoates 4 are prepared in good overall yield by conjugate addition of ß-lithiated enamines to enoates, followed by quenching with water or iodo-methane. In all cases, only one stereoisomer of the polysubstituted enamino esters 3 is produced (de > 98%).
通过将β-锂化烯胺共轭加成到烯酸酯上,然后淬灭,以良好的总收率制备单、二和三取代的5-氨基-4-烯酸叔丁酯3和单或二取代的5-氧代链烷酸叔丁酯4与水或碘甲烷。在所有情况下,仅产生多取代烯氨基酯3的一种立体异构体(de>98%)。