1,2-O-isopropylidene-5-O-tosyl-α-D-glucuronolactone

1,2-O-isopropylidene-β-D-idurono-3,6-lactone

3,6-di-O-acetyl-1,2-O-isopropylidene-5-O-toluene-p-sulphonyl-α-D-glucofuranose