Studies On Novel Sweetener Of Halo-deoxy Sucrose Derivatives

As intense sweetener of the new generation, sucralose has high degree and good characters of sweetness, high safety and stability in physical-chemical properties, which can avoid the problems existing in the applications of other sweeteners. Due to its excellent properties, sucralose is regarded as the highest accomplishment of intense sweetener up to now and applied widely in the food industry.The synthesis of sucralose is studied. Sucralose is synthesized via per-protection reaction with sucrose as raw material. Sucrose is treated with trityl chloride in pyridine at room temperature to protect the hydroxy groups at the positions of C-6, C-1', C-6' in the sucrose molecule. Then acetic anhydride is used to protect the residual hydroxy groups to give TRISPA. 4-PAS is prepared from TRISPA in dichloromethane containing acetic acid with hydrochloric acid as catalyst. 4-PAS reacts with acetic acid in methyl isobutyl ketone to get 6-PAS after acetyl migrateon. The chlorination of 6-PAS is carried out in pyridine with triphenylphosphine-carbon tetrarchloride as chlorination reagent to give TOSPA. De-acetylation of TOSPA takes place in the methanol containing sodium methoxide to get sucralose.The orthogonal text is designed in each step to optimize the reaction conditions. And the optimizations of technological parameters and catalyst have been gain. All the intermediates are characterized via mass spectrogram, IR and ~1H NMR. The properties of synthesized sucralose are tested, which accord with the criterions.On this basis, the sweetness mechanism of 4'-holo-4'-deoxy-sucralose is discussed. The synthesis of 4'-chloro-4'-deoxy-sucralose (It is 2200 times the sweetness of sucrose) is dicribed. Sucralose is treated with tert-butyldiphenylsilyl chloride to protect 6-OH, then epoxidation by isopropyl azodicarboxylate-triphenylphosphine, esterification via acetic anhydride-pyridine, de-protection of tert-butyldiphenylsilyl and esterification, addition with lithium chloride and esterification and de-protection in methanol-sodium methylate to give 4'-chloro-4'-deoxy-sucralose. By mass spectrogram, IR and ~1H NMR, 4'-chloro-4'-deoxy-sucralose is characterized...