Stereoselective synthesis of 1-deoxy-1-ethynyl-β-d-ribofuranose as a versatile scaffold

We have developed an efficient stereoselective synthesis of 1-deoxy-1-ethynyl-β-d-ribofuranose (RE), via the β-selective cyanation of the anomeric position of 1-O-acetyl-2,3,5-tri-O-benzoyl-β-d-ribofuranose. Under conditions for copper(I)-catalyzed alkyne–azide 1,3-dipolar cycloaddition, the cycloaddition of RE with 4-fluorobenzylazide was accomplished within 5 min, to afford the corresponding triazole ribonucleoside in quantitative yield.