Thiohydantoin nucleosides. Synthesis approaches

Several thiohydantoin N-nucleosides and their S-glycosides were prepared via different approaches which involved the direct glycosylation of the free thiohydantoin bases or their silylated derivatives with the corresponding sugar moieties in the presence of base or Lewis acid. Deprotection was carried out in acidic or basic medium. The site of N- and/or S-glycosylation was determined by NMR and UV measurements. In similar manner, hydantoin nucleosides were prepared.