Ring-Opening Polymerization of 3-O-Benzyl-β- l -arabinofuranose 1,2,5-Orthopivalate and Synthesis of Stereoregular (1→5)-α- l -Arabinofuranan

The ring-opening polymerization of 3- O -benzyl-β- l -arabinofuranose 1,2,5-orthopivalate ( 1 ) by BF 3 ·Et 2 O gave stereoregular 3- O -benzyl-2- O -pivaloyl-(1→5)-α- l -arabinofuranan with [α −151.4° and a number-average degree of polymerization ( ) of approximately 91. These results indicate that the substituted effects derived from the chemical synthesis of cellulose by ring-opening polymerization can be also applied to that of the arabinose ortho ester derivative. Removal of the pivaloyl and benzyl groups gave a linear stereoregular polysaccharide (1→5)-α- l -arabinofuranan.