The synthesis and biological activity of selenophenfurin (5-β-d-ribofuranosylselenophene-3- carboxamide, 1), the selenophene analogue of selenazofurin, are described. Glycosylation of ethyl selenophene-3-carboxylate (6) under stannic chloride-catalyzed conditions gave 2- and 5-glycosylated regioisomers, as a mixture of α-and β-anomers, and the β-2, 5- diglycosylated derivative. Deprotected ethyl 5-β-d-ribofuranosylselenophene-3- ...