Cross-metathesis of α-methylene-β-lactams: the first tetrasubstituted alkenes by CM
作者:Yanke Liang、Ravinder Raju、Tri Le、Christopher D. Taylor、Amy R. Howell
DOI:10.1016/j.tetlet.2008.12.060
日期:2009.3
α-Alkylidene-β-lactams have been prepared in good to excellent yields by olefin cross-metathesis. Electron-poor α-methylene-β-lactams undergo cross-metathesis more rapidly and efficiently than more electron-rich analogs. Significantly, tetrasubstituted alkenes have for the first time been accessed by CM reactions.
Synthesis of Optically Active α-Methylene β-Lactams through Lipase-Catalyzed Kinetic Resolution
作者:Waldemar Adam、Peter Groer、Hans-Ulrich Humpf、Chantu R. Saha-Möller
DOI:10.1021/jo0003089
日期:2000.8.1
is reported. The optically active alpha-methylene beta-lactams 5a-c, and their corresponding amino acids 6a-c have been readily made available throughlipase-catalyzed kinetic resolution in high enantiomeric purity (up to 99% ee). The N-substituted beta-lactam derivatives 4a, b and 10 are not accepted by the lipases and were prepared in optically active form by chemical transformation.