Synthesis and X-ray structure of a C5–C4-linked glucofuranose–oxazolidin-2-one

The formation of (4R)-4-carbamoyl-4-[(4R)-3-O-benzyl-1,2-O-isopropylidene-β-l-threofuranos-4-C-yl]-oxazolidin-2-one instead of expected imidazolidin-2,4-dione (hydantoin) derivative from 5-amino-5-cyano-5-deoxy-3-O-benzyl-1,2-O-isopropylidene-α-d-glucofuranose or 3-O-benzyl-1,2-O-isopropylidene-α-d-xylo-hexofuranos-5-ulose under Bucherer–Bergs reaction conditions is reported. Single crystal X-ray diffraction data revealed that 3T4 is the prefered conformation for the furanose ring, while E2 and 2T1 conformations are adopted by the 1,3-dioxolane and 2-oxazolidinone five-membered rings, respectively.