Synthesis Of Sucrose Derivatives And Optimization Of Catalytic Process

The chemical untilization of renewable resource sucrose was improved in order to develop its new market. With sucrose and its derivatives suralose and fructose as raw materials, a series of compounds were synthesized in various catalytic systems. Technology of the catalytic process and properties of the products were studied.Using supported catalyst NH2SO3H-SiO2, peracetylated saccharides were manufactured in the yields of more than 90.0%. The structure of products was focused onα- isomer. Even after the catalyst was recovered seven times, the yield of penta-O-acetylglucose was 93.8%.The active reagents with 2-thiazolidinethione, benzotriazole and N-hydroxyl-benzotriazole as leaving groups reacted with sucrose, and then sucrose-6-actate and sucrose-6-propanoate were obtained in the highest yield of 73.1% and 62.9% respectively. Under the cocatalyst CoCl2, sucrose reacted with anhydride regioselectively giving the natural product 3'-O-(4-methoxybenzoyl)sucrose and its analogues in approximate 60.0% yield.The catalytic effects of protonic acid, metal complex and salt were reviewed separately for the conversion of glucose into 5-hydroxymethylfurfural (HMF) assisted by microwave irradiation. Use of ZnCl2 gave the highest yield than all other catalytic systems. Under the conditions of microwave irradiation (300 W,8 min), HMF yields were 54.6%,55.1% and 80.6% from glucose, fructose and sucrose. Whereas upon conventional oil bath heating (0.11 g/mL sugar solution, weight ratio of ZnCl2 to substrate 1/4,189℃,60 min), HMF yields from glucose, fructose and sucrose were only up to 37.7%,42.7% and 57.7% respectively. Three large scale methods to manufacture FMF were studied. One method of them was that sucrose was converted to 5-chloromethylfurfural (CMF) firstly with MgCl2·6H2O as catalyst, then CMF was hydrolyzed to HMF. This method had the advantages of simple operation and convenient separation.In the system of H2SO4/acetone, 1,6-dichloro-1,6-dideoxy-2,3-O-isopropylidene-β-D-fructofuranose was synthesized conveniently from sucralose in the yield of 88.1% for the first time. After chlorosulfonation and aminolysis, the furan sulfamate containg chlorine atoms was produced with a total yield 47.4%. It was indicated that the leaving activity of several groups was Cl-6>OMs-4,Cl-1. The new compounds of 6-O-benzoyl and 6-azido-6-deoxy were also synthesized. From fructose topiramate was manufactured via three steps in the total yield of 42.3%. After regioselective hydrolysis of the isopropylidene groups in topiramate and alkylation. two new compounds N,N,O,O-tetra-ethyl and N,N,O,O-tetra-butyl derivatives were obtained.1,5-Anhydro-2,3-O-isopropylidene-β-D-fructopyranose-4-ketone was sythesized from 2,3:4,5-di-O-isopropylidene-(3-D-fructopyranose through tosylation, selective hydrolysis, intramolecular etherification and oxidation sequentially. The total yield was 23.5%. With this chiral ketone as catalyst of asymmetric epoxidation, the yield and ee value were 58.5% and 17.7% using (E)-cinnamyl alcohol as substrate. The yield and ee value were 4.9% and 95.7% using 1-O-TBS-(E)-cinnamyl alcohol as substrate.