Exo diastereoselective Diels-Alder reactions of (R)-2-phenyl-4-methylene-oxazolidin-5-one
作者:Stephen G. Pyne、Javad Safaei-G、David C.R. Hockless、Brian W. Skelton、Alexander N. Sobolev、Allan H. White
DOI:10.1016/s0040-4020(01)80808-5
日期:1994.1
diastereomeric Diels-Alder adducts. In some cases the initially formed adducts undergo epimerization at the amino-acetal carbon, however the stereochemical integrity of the quaternary α-amino acid stereogenic centre is maintained and Diels-Alder adducts can be obtained in high enantiomeric purity (> 90% ee). The stereochemistry of these adducts has been elucidated by single crystal X-ray structure determinations
(R)-2-苯基-4-亚甲基-恶唑烷基-5-酮与取代的1,3-环己二烯和取代的1,3-丁二烯的热诱导的Diels-Alder反应,得到外非对映异构体的Diels-Alder加合物。在某些情况下,最初形成的加合物在氨基乙缩醛碳上发生差向异构化,但是仍保持季α-氨基酸立体异构中心的立体化学完整性,并且可以以高对映体纯度(> 90%ee)获得Diels-Alder加合物。这些加合物的立体化学已通过单晶X射线结构测定和2D 1 H NMR分析得以阐明。