Synthesis of D-xylopyranan by the ring-opening polymerization of 3-O-benzyl-alpha-D-xylopyranose 1,2,4-orthopivalate. Attempts to synthesize a stereoregular polymer.

3-O-Benzyl-alpha-D-xylopyranose 1,2,4-orthopivalate (1) was newly synthesized and polymerized under cationic polymerization reaction conditions in order to synthesize stereoregular (1-->4)-beta-D-xylopyranan. Although the polymerization of orthopivalate 1 was carried out under various reaction conditions, a non-stereoregular polymer, but mainly consisting of (1-->4)-beta-xylopyranose units, was obtained. Comparing these results with those of glucose 1,2,4-orthopivalates, it was revealed that not only the substituents in the C-2 and C-3 positions, but also the CH(2)OR group in glucose 1,2,4-orthopivalate, largely contribute to (1-->4)-beta-glucosidic bond formation by the ring-opening polymerization.