ANIONIC CYCLOPOLYMERIZATION OF 1,2 5,6-DIANHYDRO-3,4-DI-O-METHYL-L-IDITOL LEADING TO (6-]1)-2,5-ANHYDRO-3,4-DI-O-METHYL-D-GLUCITOL/

The anionic cyclopolymerization of 1,2:5,6-dianhydro-3,4- di-O-methyl- L-iditol (3) was carried out using t-BuOK and KOH. The resulting polym er 4 consisted of 2,5-anhydro-3,4-di-O-methyl-D-glucitol as a five-mem bered repeating unit, which was identical with that of polymer 2 obtai ned from 1,2:5,6-dianhydro-3,4-di-O-methyl-D-mannitol (1). The copolym erization of 1 with 3 produced a random copolymer consisting of (1-->6 )-, (6-->1)-, (1-->1)-, and (6-->6)-linked 2,5-anhydro-3,4-di-O-methyl -D-glucitol. These facts elucidated the presence of two Linkages durin g the homopolymerization of 1 and 3, i.e., the (1-->6) and (6-->1)-bon ded 2,5-anhydro-3,4-di-O-methyl-D-glucitol units in polymers 2 and 4, respectively.