An efficient one-pot procedure is described for the conversion of a variety of hydroxyglycal esters to their 2-oxoglycosyl bromides which simply comprises of brief treatment with N-bromosuccinimide/methanol at ambient temperature. Exhibiting comparably low anomeric reactivity in glycosidation reactions, these ulosyl bromides, as well as their 2-benzoyloxyimino analogs, can readily be transformed into a range of more reactive glycosyl donors with iodine, pentenyloxy, ethylthio and dithiocarbamoyl residues at the anomeric centre, such that any ß-selective glycosidation may be successfullv achieved.
描述了一种高效的一锅法步骤,用于将多种羟基
甘油酯转化为其2-
氧基糖苷
溴化物,该过程仅涉及在室温下用N-
溴琥珀
酰亚胺/
甲醇进行简短处理。这些
氧基糖苷
溴化物在糖苷化反应中表现出相对较低的异构体反应性,同时,它们的2-
苯甲
氧羰基亚
氨基类似物也可以很容易地转化为一系列更具反应性的糖苷供体,这些供体在异构体中心具有
碘、
戊烯氧、乙
硫基和二
硫氨基甲酰基残基,从而可以成功实现任何β选择性的糖苷化反应。