Synthesis of 5-(β-D-ribofuranosyl)-1,2,4-oxadiazole-3-carboxamide

The title compound was synthesized in three steps from ethoxycarbonylformamide oxime (5) and 3,4,6-tri-O-acetyl-2,5-anhydroallonyl chloride (4b) in 62% overall yield. An acid catalyzed de-esterification was required to prevent a facile base catalyzed elimination reaction.