Synthesis of erythro and threo furanoid glycals from 1- and 2-phenylselenenyl–carbohydrate derivatives

Differently protected erythro and threo furanoid glycals were synthesized by selenoxide elimination when phenyl 1-selenoglycosides were treated in oxidizing conditions ( t BuOOH, Ti(O i Pr) 4, Et 2 i PrN). The phenyl 1-selenoglycosides were obtained from methyl 2-deoxy- d- erythro-pentofuranoside by protection of the primary hydroxyl or both hydroxyls and further reaction with PhSeH in the presence of BF 3·Et 2O. Erythro and threo furanoid glycals were also prepared by treating 2-deoxy-2-phenylselenenyl-1,4-anhydrocyclitols under similar conditions. The 2-deoxy-2-phenylselenenyl-1,4-anhydrocyclitols were obtained from 4-pentene-1,2,3-triols by a 5-endo selenium electrophilic induced cyclization. Graphic