Synthesis of polyurethanes from saccharide-derived diols and diisocyanates and their hydrolyzability

Polyurethanes with saccharide moieties in their repeating units (8 and 9) were prepared by polyaddition of methyl alpha- and beta-D-glucofuranosidurono-6,3-lactones (3 alpha and 3 beta, respectively) and 1,4:3,6-dianhydro-D-glucitol (4) with hexamethylene diisocyanate (5a) and methyl (S)-2,6-diisocyanatohexanoate (5b), which was derived from L-lysine, in N,N-dimethylformamide at 25 degrees C using dibutyltin dilaurate as a catalyst. Their properties were compared with those of the polyurethanes (6 and 7) prepared from D-glucaro-1,4:6,3-dilactone (1) and D-mannaro-1,4:6,3-dilactone (2), respectively, in our previous work. Hydrolyzability of the polyurethanes containing 1, 2, or 3 alpha units in buffer solutions was found to be higher than that of the polyurethanes derived from 3 beta or 4.