Synthesis of 3-hexuloses from 1,2 : 5,6-di-O-isopropylidenehexitols

A simple, but low-yielding method for the synthesis of 3-hexuloses has been elaborated. Oxidation of 1,2:5,6-di-O-isopropylidenehexitols with bromine in the presence of barium carbonate, followed by mild-acid hydrolysis of th e oxidation products gave the free hexuloses. Oxidation occurred at only on e of the carbon atoms bearing free hydroxyl groups. From the D-mannitol der ivative, D-arabino-3-hexulose was obtained via the di-O-isopropylidene deri vative, whereas the D-glucitol derivative gave a mixture of the 1,2:5,6-di- O-isoprpylidene derivatives of L-xylo- and D-ribo-3-hexulose, separable by column chromatography. Mild-acid hydrolysis of the oxidation products affor ded the free hexuloses. (C) 2001 Elsevier Science Ltd. All rights reserved.