Synthesis of diblock methylcellulose derivatives with regioselective functionalization patterns

This article describes a new synthesis strategy to prepare diblock copolymers as model compounds for industrially produced cellulose ethers exemplified with methylcellulose (MC). To elucidate a key structure for thermoreversible gelation of MC, five regioselectively methylated celluloses 1–5 (236, 23, 26, 3, and 6 MC), five corresponding methyl-β-D-glucopyranosyl-(1→4)-cellulosides 6–10, and five equiv methyl-β-D-glucopyranosyl-(1→4)-β-D-glucopyranosyl-(1→4)-cellulosides 11–15 were synthesized for the first time via combination of the glycosyl trichloroacetimidate method and the acid-catalyzed methanolysis method. The structure of compounds 1–15 was confirmed by means of NMR spectroscopy and MALDI-TOF MS. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011