The crystal structure of the title compound, C12H19NO6, was determined in order to ascertain its relative configuration. It was synthesized by the stereospecific reduction of the novel oxime derived from 5-O-acetyl-1,2-isopropylidene-3-oxo-alpha-D-ribofuranose and comprises two cis-fused heterocyclic five-membered rings, furanose and dioxolane, which adopt envelope conformations.