6-deoxy-D-mannono-1,4-lactone

(+)-(3R,4S,5R)-3-hydroxy-4-mesyloxy-5-methyldihydro-2(3H)-furanone

(+)-(3R,4S,5R)-3-hydroxy-4-p-nitrobenzoyloxy-5-methyldihydro-2(3H)-furanone