Stereoselective synthesis of carbocyclic L-4'-fluoro-2',3'-dideoxyadenosine

[formula: see text] L-(1'S,3'S)-9-[3-Fluoro-3-(hydroxymethyl)cyclopentan-1-yl]adenine 15 has been synthesized from ester 2, which can be conveniently prepared from 2,3-isopropylidene-D-glyceraldehyde 1 in six steps. The key ring closure has been accomplished through an intramolecular nucleophilic substitution reaction.