| Abstract
| - A synthesis of 9-(2,3-dideoxy-2-fluoro-β-d-threo-pentofuranosyl)adenine (1, FddA) via a 6-chloro-9-(3-deoxy-β-d-erythro-pentofuranosyl)-9H-purine (9), which was readily obtained from inosine (5),is described. Fluorination at the C2‘-β position of the purine 3‘-deoxynucleoside with diethylaminosulfur trifluoride was improved by the introduction of a 6-chloro group and proceeded in moderateyield. Purine 3‘-deoxynucleoside derivatives were also subjected to nucleophilic reactions withtriethylamine trihydrofluoride and gave the desired fluorinated nucleoside in good yield. The safetyand yield of the fluorination process were greatly improved by the use of triethylamine trihydrofluoride. The influence of the sugar ring conformation and 6-chloro group on the rate of thenucleophilic reaction against elimination are also discussed.
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