Six new polysaccharide carbamate derivatives

［6-cyclohexyl-2

3-bis(3

5-dimethylphenyl)］- carbamate

［6-cyclohexyl-2

3-bis(3

5-dichlorophenyl)］carbamate and ［6-cyclohexyl-2

3-bis(4- chlorophenyl)］carbamate of cellulose and amylose

were synthesized by a sequential regioselective process based on the protection and deprotection of 6-position of a glucose unit.These derivatives were then used as the chiral stationary phases (CSPs) for high-performance liquid chromatography (HPLC) after being coated on the surface of aminopropyl silica gel.The structures of the obtained derivatives were characterized by 1H-NMR and FTIR spectroscopies

and their chiral recognition abilities were evaluated using nine racemates by HPLC.Some racemates were better resolved on the new derivatives

compared with the well-known monosubstituted and disubstituted phenylcarbamate derivatives

such as tris(3

5-dimethylphenylcarbamate)

tris(3

5-dichlorophenylcarbamate)

tris(4-chlorophenylcarbamate) and tris(cyclohexylcarbamate) of the cellulose and amylose with high chiral recognition ability.The higher order structure of the new derivatives seems to be changed through the selective introduction of a cyclohexyl group onto the 6-position of the glucose unit

which must influence the chiral recognition ability of the new derivatives.The obtained results indicate that three novel cellulose derivatives show higher chiral recognition ability than three amylose derivatives for most of the racemates in the study.And the property and position of substituents at 2-

3- and 6-position of glucose unit have a great influence on the chiral recognition ability of cellulose and amylose carbamate derivatives.