Stereocontrolled General Synthesis of Pyrimidine<i>C</i>-Nucleosides Having Branched-chain Sugar Moieties
作者:Tsuneo Sato、Makoto Watanabe、Hiroshi Kobayashi、Ryoji Noyori
DOI:10.1246/bcsj.56.2680
日期:1983.9
variety of pyrimidine C-nucleosides bearing branched-chain sugars can be synthesized starting from adequately substituted (1R*,6S*,7S*,8R*)-7,8-isopropylidenedioxy-3,9-dioxabicyclo[4.2.1]nonan-4-ones. The general procedure consists of condensation with t-butoxybis(dimethylamino) methane, giving the corresponding α-dimethylaminomethylene lactones, base-catalyzed heterocycle formation with urea, thiourea
从充分取代的 (1R*,6S*,7S*,8R*)-7,8-isopropylidenedioxy-3,9-dioxabicyclo[4.2.1]nonan 开始,可以合成多种带有支链糖的嘧啶 C-核苷-4个。一般程序包括与叔丁氧基双(二甲氨基)甲烷缩合,得到相应的 α-二甲氨基亚甲基内酯,碱催化与尿素、硫脲或胍形成杂环,以及酸促进去除异亚丙基保护基团。整体转化继续保留立体化学以仅提供 C-β-糖基核苷结构。