Stereoselective N-glycosylation with N4-acyl cytosines and efficient synthesis of gemcitabine
作者:Tongchao Liu、Jiadeng Tang、Jianpeng Liang、Yabin Chen、Xiaowen Wang、Jingkang Shen、Dongmei Zhao、Bing Xiong、Jun-Da Cen、Yue-Lei Chen
DOI:10.1016/j.tet.2019.01.027
日期:2019.3
gemcitabine synthesis, highly beta-stereoselective and high yielding TBAI catalyzed N-glycosylation was achieved with N4-Bz cytosine and anomeric mixture of 2,2‘-difluororibose mesylate donor. The subsequent global deprotection gave gemcitabine efficiently. Meanwhile, the anomeric chloride intermediate and fluoride-displaced side products of this N-glycosylation were identified, too. This new glycosylation
通过在吉西他滨合成的糖基化步骤中各种N 4保护的胞嘧啶衍生物的系统比较,使用N 4 -Bz胞嘧啶和2,2'-二氟核糖基甲磺酸酯的异头混合物,实现了高β-立体选择性和高产率的TBAI催化的N-糖基化。捐赠者。随后的整体脱保护有效地赋予了吉西他滨。同时,还鉴定出该N-糖基化的异头氯化物中间体和氟化物置换的副产物。这种新的糖基化方法揭示了N 4的重要性嘧啶核苷立体选择性制备中的β-保护,也为吉西他滨目前的工业生产提供了潜在的替代方法。