Study on the fluorination of 1, 2-O-isopropylidene D-pentofuranose with DAST and its scalable application

•Scalable synthesis of rare d-lyxose.•Scalable synthesis of 3′-fluoro-3′-deoxy-β-d-ribofuranosyl-7-halogen-7-deazapurine derivative.•Inversion of configuration of d-pentofuranosides promoted by DAST reagent. The research focuses on the inversion of configuration at C3 of 1,2-O-isopropylidene-d-arabinofuranoside and d-ribofuranoside promoted by DAST. Both the initial configuration and the presence of C5 acyl group in d-furanosides are the key factors for this inversion due to the formation of cyclic oxonium ion intermediates. This inversion of configuration has been successfully applied to scalable synthesis of d-lyxose and 2′,5′-di-O-benzoyl-3′-fluoro-3′-deoxy-β-d-ribofuranosyl-7-halogen-7-deazapurine. [Display omitted]