1,6-Anhydro-2,3,4-tri-O-benzyl-beta-D-talopyranose (1) was synthesized and polymerized to compare its polymerizability with that of other benzylated 1,6-anhydrohexopyranoses reported previously. In methylene chloride at -60 degrees C, phosphorus pentafluoride as the initiator gave stereoregular polymers (2) with nurnber-average molecular weights (M-n) of 9500-19 600. The polymerizability was analyzed based on the configuration of the hydroxyl groups and conformational change of the pyranose ring during polymerization. The monomer reactivity ratios resulting from copolymerization with 1,6-anhydro-2,3,4-tri-O-benzyl-beta-D-glucopyranose (4) were also compared. The present monomer I required a large amount of the initiator for polymerization. P-31 NMR results of polymerization suggested that considerable amounts of the initiator coordinated with not only the oxygen of the 1,6-anhydro ring of the monomer but also those of the polymer. This additional coordination of the initiator with the polymer oxygens is expected to decrease the initiation efficiency. Debenzylation resulted in a new stereoregular polysaccharide, (1 -> 6)-alpha-D-talopyranan (3).