3-Deoxy-3,3-difluoro-<scp>d</scp>-arabinofuranose: First Stereoselective Synthesis and Application in Preparation of <i>g</i><i>em</i>-Difluorinated Sugar Nucleosides
作者:Xingang Zhang、Hairong Xia、XiCheng Dong、Jing Jin、Wei-Dong Meng、Feng-Ling Qing
DOI:10.1021/jo034512i
日期:2003.11.1
The design and synthesis of gem-difluorinated sugar nucleosides were described. The key intermediate, 3-deoxy-3,3-difluoro-d-arabinofuranose 9, was first stereoselectively prepared from the chiral gem-difluorohomoallyl alcohol 12. The kinetic formation of single anti-14 in the benzylation of 12 could be accomplished by controlling the amount of sodium hydride used. The dihydroxylation of 14 (a mixture
描述了宝石二氟化糖核苷的设计与合成。关键的中间体3-脱氧-3,3-二氟-d-阿拉伯呋喃糖9首先是从手性的gem-difluorohomoallyl醇12立体选择性地制备的。可以通过控制12的苄基化反应来实现单一抗14的动力学形成。氢化钠的用量。14(反异构体和顺式异构体的混合物)的二羟基化,然后脱保护和立体氧化,选择性地得到在C2位具有阿拉伯糖构型的呋喃糖9。由9通过糖基化反应制备N(1)-(3-脱氧-3,3-二氟-β-D-阿拉伯呋喃糖基)胞嘧啶6。4'-硫呋喃糖25很容易从9合成。25的氧化,然后与甲硅烷基化的N(4)-苯甲酰胞嘧啶缩合(Pummerer反应)未能得到我们所需要的受保护的核苷1'3'-脱氧3',3'-二氟-4'-硫代胞嘧啶核苷27',但得到区域异构体27。Pummerer反应的区域化学由4'-硫呋喃糖25的α-质子的动力学酸性确定。