| 摘要 |
A method is provided for the preparation of a sucrose 6-ester by: (i) reacting a solution of sucrose in an inert organic solvent with a reagent selected from the group consisting of a trialkyl orthoester and a ketene acetal, in the presence of an acid catalyst to provide a sucrose alkyl 4,6-orthoester, (ii) treating the sucrose alkyl 4,6-orthoester under mild aqueous acidic conditions to provide a mixture of sucrose 4- and 6-monoesters, (iii) treating the mixture of esters with a base to convert the sucrose 4-ester into sucrose 6-ester, and (iv) neutralizing the solution and isolating the sucrose 6-ester, in which stage (i) is effected in a continuous manner by passing the solution of sucrose and reagent through a strong acid macroreticular ion exchange resin at ambient temperature. Sucralose is prepared by chlorinating the sucrose 6-esters obtained.
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