An improved synthesis of 9-(2,3-dideoxy-2-fluoro-β-d-threo-pentofuranosyl)adenine (1, FddA) via a fluorination of 3′-O-benzoyl-5′-O-tritylriboside (4a) using noncorrosive triethylamine trihydrofluoride (Et₃N·3HF) is described. The method is suitable for large-scale synthesis. In particular, the synthesis of the pivotal intermediate 4a was much improved in avoidance of the use of toxic tin reagent. Radical deoxygenation with several silanes was also studied. The total yield of FddA from 6-chloropurine riboside (2) in this study was greater than that we reported previously.

中文翻译：

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使用三乙胺三氟化氢改进9-（2,3-二脱氧-2-氟-β-d-苏-戊呋喃糖基）腺嘌呤（FddA）的合成

通过3' - O-苯甲酰基-5' - O-三苯甲基核糖苷的氟化反应（4a）合成9-（2,3-二脱氧-2-氟-β-d-苏-戊呋喃糖基）腺嘌呤（1，FddA）的改进方法）描述了使用非腐蚀性的三氟三乙胺（Et ₃ N·3HF）。该方法适用于大规模合成。尤其是，避免使用有毒的锡试剂大大改善了枢轴中间体4a的合成。还研究了几种硅烷的自由基脱氧。在这项研究中，来自6-氯嘌呤核糖苷（2）的FddA的总产量比我们先前报道的要高。