The thermally induced hetero-Diels-Alder reaction of vinyl ethers 2a-d and N-acylenaminones 3a-h leads to the diastereomeric adducts 4a-h and 5a-h in 75–98% yield providing -compounds 4a-h as the main products. Isomerisation of 4a-f with Lewis acids gives the thermodynamically more stable 5a-f. Transformation of 4 and 5 by hydrogenation leads to 3-amino sugar glycosides.
乙烯基醚2a-d和N-酰基亚
氨基3a-h的热诱导异Diels-Alder反应导致非对映体加合物4a-h和5a-h的产率为75-98%,提供了4a-h化合物作为主要产物。用
路易斯酸将4a-f异构化,可得到热力学上更稳定的5a-f。通过氢化转化4和5产生3-
氨基糖苷。