Scalable synthesis of substituted 2,7-dimethyl-9-phenylxanthen-9-ol (DMPx-OH): useful for the preparation of crystalline 5′-O-DMPx-protected nucleosides
作者:Shyamapada Banerjee、P. Srishylam、S. Rajendra Prasad、Michael T. Migawa、Eric E. Swayze、Yogesh S. Sanghvi
DOI:10.1016/j.tetlet.2012.06.081
日期:2012.8
A convenient single-step synthesis of several 2,7-dimethyl-9-phenylxanthen-9-ol (DMPx-OH) analogs has been accomplished using a Friedel–Crafts reaction. Treatment of various DMPx-OH with unprotected 2′-O-methoxyethyl-ribonucleosides (MOE) in the presence of B(C6F5)3, as a Lewis Acid catalyst, furnished 5′-O-protected derivatives of 2′-MOE-ribonucleosides in good yields. The deprotection of the DMPx
使用Friedel-Crafts反应已经完成了几种2,7-二甲基-9-苯基黄嘌呤9-醇(DMPx-OH)类似物的便捷一步合成。在路易斯酸催化剂的B(C 6 F 5)3存在下,用未保护的2' - O-甲氧基乙基-核糖核苷(MOE)处理各种DMPx-OH ,得到5'- O-保护的2'-衍生物MOE-核糖核苷产率高。DMPx基团的脱保护是通过在非常温和的条件下进行酸水解来实现的。在合成的五个DMPx类似物中,2,7-二甲基-9-(4-硝基苯基)氧杂蒽-9-基团提供了结晶产物,使得能够进行非色谱分离5'- O - Protetcated核苷。