Novel cis-1,2-fused1,3-oxathiolan-, 1,3-oxaselenolan-, and 1,3-oxazolidin-2-iminecarbohydratederivatives have been prepared by treatment of the corresponding 1,2-anhydrosugars with potassium thiocyanate, potassium selenocyanate, and sodium cyanamide, respectively. The procedure is compatible with several protecting groups such as acyl, benzyl, and silyl and also with sugars of different configurations