The sugar moiety of adenosine, inosine, or guanosine was protected with a tert-butyldimethylsilyl group. The C-8 lithiation of these protected nucleosides was carried out with lithium diisopropylamide in tetrahydrofuran at below -70°C. The reactions of the C-8-lithiated species with MeI, HCO2Me, and ClCO2Me were examined. The resulting products having a carbon substituent at the C-8 position were converted to the corresponding 8-carbon-substituted purine nucleosides by treatment with tetrabutylammonium fluoride. The whole sequence constitutes a simple method for the preparation of 8-carbon-substituted purine nucleosides from intact purine nucleosides.
腺苷、
肌苷或
鸟苷的糖部分被特丁基二甲基
硅基保护。对这些保护的核苷进行了C-8
锂化反应,反应使用了
二异丙基胺锂,在低于-70°C的
四氢呋喃中进行。C-8
锂化物与MeI、HCO2Me和ClCO2Me的反应进行的研究。所得到的在C-8位有碳取代基的产物经过四丁基
氟铵处理后转化为相应的8-碳取代的
嘌呤核苷。整个过程构成了一种从完整的
嘌呤核苷制备8-碳取代
嘌呤核苷的简单方法。