The reaction of benzyl 4, 5, 7, 8, 9-penta-O-acetyl-2-bromo- or -chloro-2, 3-dideoxy-D-glycero-β-D-galacto-2-nonulopyranosonate (2, 3) with uridine, 5-fluorouridine, and cytidine under Koenigs-Knorr reaction conditions gave the corresponding (2→5) linked disaccharide uncleoside derivatives, in yields of 32-47%. A similar reaction of 3 with inosine gave the (2→N¹) linked derivative. These uncleoside analogues were converted into the final target compounds.The configuration at the anomeric position of these compounds was elucidated by means of proton and carbon unclear magnetic resonance (¹H-, ¹³C-NMR)analysis, and consideration of the rate of hydrolysis of the (2→5) glycosidic linkage.