A three-step reaction sequence starting from a ribonucleoside to give the corresponding 5′-O-acyl-2′,3′-didehydro-2′,3′-dideoxynucleoside is described. The key intermediate is the bromoacetate, made by reaction of the 2′,3′-methoxyethylidene nucleoside with acetyl bromide. Reductive elimination of the bromoacetate using a zinc-copper couple furnishes the desired compounds in good overall yield.
描述了一种从
核糖核苷开始的三步反应序列,最终得到相应的5'-O-酰基-2',3'-二脱氧-2',3'-二氢核苷。关键中间体是
溴乙酸酯,由2',3'-甲氧基亚乙基核苷与
乙酰溴反应制得。利用
锌-
铜偶对
溴乙酸酯进行还原消除,可在良好的总体产率下获得目标化合物。