Thin layer chromatography was used to separate and analyze the samples in the process of preparation of β d glucopyranose 1 bromo 2 amino 2,3,4,6 tetra acetyl ester.The best developing solvent system is ethyl acetate...Thin layer chromatography was used to separate and analyze the samples in the process of preparation of β d glucopyranose 1 bromo 2 amino 2,3,4,6 tetra acetyl ester.The best developing solvent system is ethyl acetate∶methane alcohol∶water=6∶3∶0.5(V/V).The reactants, inter mediates and products could be separated effectively,thus indicated the reaction progression obviously.展开更多
N-acetyl-2-thiazolidinethione(Ⅰ),N-propanoyl-2-thiazolidinethione(Ⅱ),N-acetylbenzotriazole(Ⅲ),N-propanoylbenzotriazole(Ⅳ),N-acetoxybenzotriazole(Ⅴ) and N-propanoxybenzotriazole(Ⅵ) were first synthesized.The resu...N-acetyl-2-thiazolidinethione(Ⅰ),N-propanoyl-2-thiazolidinethione(Ⅱ),N-acetylbenzotriazole(Ⅲ),N-propanoylbenzotriazole(Ⅳ),N-acetoxybenzotriazole(Ⅴ) and N-propanoxybenzotriazole(Ⅵ) were first synthesized.The resulting active reagents reacted with sucrose to obtain sucrose-2-esters,followed by an intramolecular shift mechanism to afford the final product sucrose-6-esters with the best yield of 73.1% in the presence of the catalyst 1,8-diazabicycloundec-7-ene(DBU).It’s indicated that the acyl regents using 2-thiazolidinethione as leaving group possess favorable regioselectivity from the experimental data in synthesizing sucrose-6-acetate(1) and propanoate(2).展开更多
文摘Thin layer chromatography was used to separate and analyze the samples in the process of preparation of β d glucopyranose 1 bromo 2 amino 2,3,4,6 tetra acetyl ester.The best developing solvent system is ethyl acetate∶methane alcohol∶water=6∶3∶0.5(V/V).The reactants, inter mediates and products could be separated effectively,thus indicated the reaction progression obviously.
文摘N-acetyl-2-thiazolidinethione(Ⅰ),N-propanoyl-2-thiazolidinethione(Ⅱ),N-acetylbenzotriazole(Ⅲ),N-propanoylbenzotriazole(Ⅳ),N-acetoxybenzotriazole(Ⅴ) and N-propanoxybenzotriazole(Ⅵ) were first synthesized.The resulting active reagents reacted with sucrose to obtain sucrose-2-esters,followed by an intramolecular shift mechanism to afford the final product sucrose-6-esters with the best yield of 73.1% in the presence of the catalyst 1,8-diazabicycloundec-7-ene(DBU).It’s indicated that the acyl regents using 2-thiazolidinethione as leaving group possess favorable regioselectivity from the experimental data in synthesizing sucrose-6-acetate(1) and propanoate(2).
