Study on the Selectivity of Benzoylation of Metal Chelates of Sucrose1
作者:
JuanL. Navia,
RichardA. Roberts,
RobertE. Wingard,
期刊:
Journal of Carbohydrate Chemistry
(Taylor Available online 1995)
卷期:
Volume 14,
issue 4-5
页码: 465-480
ISSN:0732-8303
年代: 1995
DOI:10.1080/07328309508005351
出版商: Taylor & Francis Group
数据来源: Taylor
摘要:
A study of the selectivity of metal chelate-directed benzoylation of sucrose dianion, relative to unchelated sucrose anion, was conducted as part of a study on new synthetic approaches to the high-potency sweetener sucralose. Ionic complexes of sucrose with various metal ions were prepared in DMF and the resulting complexes reacted at low temperature with benzoic anhydride. Cobalt and manganese salts directed esterification mostly to the 3′-OH on the fructosyl portion. Unchelated sucrose anion and other metals favored esterification at the 2-OH of the glucosyl portion. Migration of the benzoate ester along the glucose portion was observed in the directionO-2 toO-6 at moderate temperature, but at higher temperature transannular migration was observed from the glucose to the fructose ring. Reaction mixtures were analyzed by HPLC and monobenzoates identified by retention times relative to standards. Six of eight possible monobenzoates of sucrose were isolated from mixtures and identified by their1H NMR spectra.
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