4-METHOXY SUBSTITUTED TRITYL GROUPS IN 6-O PROTECTION OF CELLULOSE - HOMOGENEOUS SYNTHESIS, CHARACTERIZATION, DETRITYLATION

The reaction of cellulose with methoxy-substituted triphenylmethyl chl orides under homogeneous conditions in the presence of pyridine was ca rried out with the aim to develop new protective groups for cellulose simply introducable and completely removable under mild conditions. Th e obtained cellulose ethers dissolve well in solvents such as N,N-dime thylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, 1,4-dioxane and tetrahydrofuran and show a high 6-0 selectivity. The study proves that the speed of tritylation as well as of detritylation increases in the order unsubstituted onomethoxytrityl/dimethoxytrityl/trimethoxytr ityl. The substituent distribution of the methoxy-substituted tripheny lmethyl ethers of cellulose was determined by means of C-13 NMR spectr oscopy of the polymers and by high-performance liquid chromatography a fter chain-degradation. Since the methoxy substituted trityl groups we re introduced faster and removed easier than the unsubstituted trityl group, they are, therefore, useful tools for a regioselective synthesi s of 2,3-functionalized cellulose derivatives.