Glucose 3,5-phenylboronate, preparation

Zenkl et al. [51] presented another approach to design saccharide-sensitive nanobeads. They prepared particles (0 380 nm) based on poly (/V- i sopropy I aery I am ide) cross-linked with phenylboronic acid moieties. In the presence of a saccharide (glucose or fructose) the particles reversibly swell due to the formation of negative charges. A FRET-indicator couple (fhiorescein/rhodamine) is used to monitor the... 

Methacrylic anhydride in pyridine, applied to 1,6-anhydro-D-glucose 2,4-phenylboronate, gave the 3-methacrylate, from which an addition polymer was prepared.78... 

The first, satisfactory methylation appears to have been effected by Bourne and his colleagues,48 who prepared 6-O-methyl-D-glucose in high yield from the l,2 3,5-bis(phenylboronate), using diazomethane and boron trifluoride etherate in dichloromethane for methylation, and a final separation on a column of cellulose powder. It is this procedure which the same group used for structural analysis of triol phenylboron-ates43 (see Section 111,1) others80 have attempted to use it, but without success. 

Maekawa er al. reported that a series of co-oxazolylalkanoic acid derivatives as antidiabetic agents, promoting the glucose-dependent secretion of insulin. (o-(5-Oxazolyl)alka-noates 27, the key intermediates for the synthesis of target compounds, were prepared via Suzuki coupling of substituted 2-chlorooxazole with phenylboronic acid [34]. 

A study of the stability of compounds derived from D-glucose and D-fructose with boric acid or phenylboronic acid has found that the stability constants for the fructose compounds are much greater than those for the glucose compounds. The synthesis of crystalline 3-0-acetyl-2,4-0-phenylboranediyl- -D-ribopyranosyl bromide in a two pot process from D-ribose has been described along with some of its selective glycosylation reactions. Ethyl (dimethoxy)borane has been used in the synthesis of anomerically pure furanosides from the free sugars. Thus methyl 2,3-0-ethylboranediyl-tt-D-lyxofuranoside was prepared and then de-esterified under essentially neutral conditions to the glycoside in 80%... 

Except for the adsorption of metal ions, chitosan gels can be applied in the adsorption of organic substances. Novel gels from phenylboronate derivatives of chitosan were prepared for the adsorption of saccharides hy Matsumoto et al. [40]. The adsorption characteristics of D-glucose and 1-methyl-a-D-glucoside on the gels were examined and compared with a commercial gel. The resulted showed that the chitosan gels were inferior to the commercial gel in their adsorption capacity. 

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