REGIOSELECTIVITY AND STEREOSELECTIVITY IN CATIONIC CYCLOPOLYMERIZATIONS OF 1,2-5,6-DIANHYDRO-3,4-DI-O-METHYL-D-MANNITOL AND 1,2-5,6-DIANHYDRO-3,4-DI-O-METHYL-L-IDITOL AND THE SYNTHESIS OF OLY[(1-]6)-2,5-ANHYDRO-3,4-DI-O-METHYL-D-GLUCITOL]

The cyclopolymerizations of 1,2:5,6-dianhydro-3,4-di-O-methyl-D-mannit ol (1) and -L-iditol (2) were carried out using BF3 . OEt(2) and SnCl4 . The polymers obtained were soluble in chloroform, methanol, tetrahyd rofuran, and water but insoluble in n-hexane. The specific rotations ( [alpha](22)(546)) of the polymers were +41.3 to +73.2 degrees for 1 an d +38.2 to +62.9 degrees for 2 (c = 1.0, CHCl3). For all the polymers, the extent of cyclization was 100%. The structure of the polymers obt ained from both 1 and 2 was (1-->6)-bonded 2,5-anhydro-3,4-di-O-methyl -D-mannitol as the 5-membered constitutional unit, namely, poly[(1-->6 )-2,5-anhydro-3 ,4-di-O-methyl-D-glucitol]. The n-hexane-soluble produ cts, which were obtained together with the n-hexane-insoluble polymers for the polymerization using BF3 . OEt(2), contained 1,6:2,5-dianhydr o-3 ,4-di-O-methyl-D-glucitol, the cyclic dimer of 2,5-anhydro-3,4-di- O-methyl-D-glucitol and its higher cyclic homologs.