An efficient large-scale synthesis of gemcitabine employing a crystalline 2,2-difluoro-α-ribofuranosyl bromide
作者:Young-Kil Chang、Jaeheon Lee、Gha-Seung Park、Moonsub Lee、Chul Hyun Park、Han Kyong Kim、Gwansun Lee、Bo-Young Lee、Ju Yuel Baek、Kwan Soo Kim
DOI:10.1016/j.tet.2010.05.039
日期:2010.7
An efficient large-scale synthesis of gemcitabine was achieved without chromatography or fractional crystallization. The key steps include stereospecific conversion of a novel β-ribofuranosyl phosphate into a highly crystalline α-ribofuranosyl bromide and coupling of the α-ribofuranosyl bromide and trimethylsilyl cytosine to produce a β-nucleoside. p-Phenylbenzoyl group was introduced for the protection
在没有色谱法或分级结晶的情况下,实现了吉西他滨的有效大规模合成。关键步骤包括将新型β-呋喃呋喃糖基磷酸酯立体定向转化为高度结晶的α-呋喃呋喃糖基溴化物,以及将α-呋喃呋喃糖基溴化物和三甲基甲硅烷基胞嘧啶偶联以产生β-核苷。为了增强中间体的结晶度,引入对苯基苯甲酰基用于保护羟基之一。通过蒸馏从反应介质中连续除去偶联反应过程中产生的三甲基甲硅烷基溴,大大提高了关键偶联反应的β-选择性。