A new practical synthesis strategy has been developed to access­ the β-d-arabinofuranosyl purine nucleosides fludarabine and nelarabine. In our approach, an ortho-alkyne benzoyl ester is transiently introduced as a neighbouring-participation group in Vorbrüggen glycosylation to afford the corresponding β-nucleoside exclusively. The latter was further removed efficiently by using freshly prepared Ph₃PAuOTFA to give the corresponding 2′-OH nucleosides without transesterification. After reversion of the configuration of 2′-OH and deprotection, fludarabine and nelarabine were obtained in high yield and purity.

中文翻译：

---

氟达拉滨和奈拉拉滨的实用合成

已经开发出一种新的实用合成策略来获得β- d-阿拉伯呋喃糖基嘌呤嘌呤核苷氟达拉滨和奈拉拉滨。在我们的方法中，在Vorbrüggen糖基化中将邻炔基苯甲酸酯作为邻居参与基团暂时引入，以专门提供相应的β-核苷。通过使用新鲜制备的Ph ₃ PAuOTFA将后者进一步有效除去，得到相应的2'-OH核苷而不进行酯交换反应。还原2'-OH的构型并脱保护后，可以高收率和纯度获得氟达拉滨和奈拉拉滨。