Synthesis and ring-opening polymerization of new 1,4-anhydro-glucopyranose derivatives

Abstract

Three new 1,4-anhydro-glucopyranose derivatives having different hydroxyl protective groups such as 1,4-anhydro-2,3,6-tri-O-methyl-α-D-glucopyranose (AMGLU), 1,4-anhydro-6-O-benzyl-2,3-di-O-methyl-α-D-glucopyranose (A6BMG), and 1,4-anhydro-2,3-di-O-methyl-6-O-trityl-α-D-glucopyranose (A6TMG) were synthesized from methyl α-D-glucopyranoside in good yields. Their polymerizability was compared with that of 1,4-anhydro-2,3,6-tri-O-benzyl-α-D-glucopyranose (ABGLU) reported previously. The trimethylated monomer, AMGLU, was polymerized by a PF5 catalyst to give 1,5-α-furanosidic polymer having number-average molecular weights (M̄n) in the range of 2.8 × 103 to 6.8 × 103. The 13C-NMR spectrum was compared with that of methylated amylose and cellulose. Other anhydro monomers, A6BMG and A6TMG, gave the corresponding 1,5-α furanosidic polymers having M̄n = 17.1 × 103 and 1.8 × 103, respectively. Thus, the substituents at the C2 and C6 positions were found to play an important role for the ring-opening polymerizability of the 1,4-anhydro-glucose monomers. In addition, debenzylation of the tribenzylated polymer gave free (1 → 5)-α-D-glucofuranan. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 841–850, 1998