Syntheses and comparison of 2,6-di-O-methyl celluloses from natural and synthetic celluloses

2,6-Di-O-methylcellulose was prepared from natural and synthetic celluloses. Natural cellulose was converted to 2,6-di-O-thexyldimethylsilylcellulose, then to 3-mono-O-allyl-2,6-di-O-methylcellulose, and finally into 2,6-di-O-methylcellulose. Alternatively, 2,6 di-O-methylcellulose was synthesized from the synthetic cellulose derivative 3-mono-O-benzyl-2,6-di-O-pivaloylcellulose by depivaloylation and methylation to give 3-mono-O-benzyl-2,6-di-O-methylcellulose, which was debenzylated to yield the dimethyl ether. Both types of 2,6-di-O-methylcellulose are insoluble in water and common organic solvents. The structures of all cellulose derivatives were determined by NMR.