Structural bias effect on fluorination at C-1 and C-2 of alkyl-3,6-anhydro-D-hexofuranosides: Syntheses of 2-fluoro sauropunols and glycosyl fluorides

Published in: Carbohydrate Research, Date: September 2026, Article: 110008, Volume: Volume 567

DOI: 10.1016/j.carres.2026.110008

Authors: Susanta Das[TCGLS Member], Ratul Hore, Sayanta Paria[TCGLS Member], Anirban Pradhan, Mrinalkanti Kundu[TCGLS Member], Joykrishna Maity

Abstract: Natural sauropunols A-D, F, and H contain a 3,6-anhydro-2-deoxy-d-glucofuranose sugar backbone, and most of them have anti-inflammatory activity. Reaction of DAST with 2-hydroxy group of the α-anomer of alkyl-3,6-anhydro-5-O-benzoyl-D-glucofuranosides yielded 2-β-fluorosauropunol A and its analogues. On the other hand, the corresponding β-anomer produced α-glycosyl fluoride based on 3,6-anhydro-mannofuranose core through 1,2-migration of anomeric alkoxy groups. A similar reaction of alkyl-3,6-anhydro-5-O-benzoyl-β-d-mannofuranosides, obtained from the corresponding β-d-glucofuranoside through appropriate oxidation and reduction reactions, yielded 2-α-fluorosauropunols A-D, F, H, and 1,4-disubstituted triazole appended glycoconjugate of 2-α-fluorosauropunol F. Eventually, using the structural bias of the substrates, eight 2-fluorosauropunol derivatives and nine glycosyl fluorides were synthesised with good yields and functional group tolerance.