Furanoid glycal was utilized as a starting material for the nucleoside derivatives with the aid of benzenesulfenyl chloride. Condensation reaction with silylated nucleic bases was high in the presence of SnCl 4 . Electrophilic addition of benzenesulfenyl chloride to the glycal with substituent also proceeded in high stereoselectivity. Phenylthio-substituted nucleoside was used to convert 2',3'-dideoxynucleoside and 2',3'-didehydro-2',3'-dideoxynucleoside