The preparation of 4,6-dichloro-4,6-dideoxy-α-d-galactopyranosyl 6-chloro-6-deoxy-,β-d-fructofuranoside and the conversion of chlorinated derivatives into anhydrides

Chemoenzymatic Preparation of Sugar-Based Hydrogels

We have prepared sugar-based hydrogels using a chemoenzymatic synthetic approach. Specifically, the regioselectivity of enzymes was used to prepare sugar acrylate monomers. These monomers were polymerized with a crosslinker in a standard free radical polymerization. The polymers consist of a polyacrylate backbone with sucrose, (α-methyl glucoside, or β-methyl galactoside pendant groups. These materials are highly water absorbent swelling to more than 100 times their initial weight when placed in water. The degree of swelling for poly(β-methyl galactoside 6-acrylate) hydrogel was relatively insensitive to pH (from pH 4.5-9) and ionic strength (0.15-3 M NaCl). Potential applications of these materials include waterabsorbents and drug delivery systems.

Tin(IV)-functionalised polymer supports; non-toxic and practical reagents for regioselective acetylation of sucrose

Polymer-supported butyltin(IV) reagents have been surveyed for regioselectivity in acetylation of sucrose. Polymer-supported butyltin(IV) dichloride 8 catalysed the acetylation of sucrose to give a 59% yield of 6-O-acetyl sucrose 3, the precursor of sucralose. The yield is close to that of a previously reported process involving dibutyltin(IV) oxide (Bu2SnO). The spent polymeric resin could readily be regenerated and can be subsequently used in further synthetic reactions.

Relationship between the structure and the properties of carbohydrates in aqueous solutions: sweetness of chlorinated sugars

The structural basis of the sweet taste of D-galactose, D-glucose, D-mannose, sucrose, and some of their chlorinated derivatives has been derived from an interpretation of their F.t.-i.r. spectra. AH-B glucophores are proposed in the light of the observed OH vibrations, and an explanation of the differences in sweetness of the monosaccharides is proposed. The hydrophobic character of the CH2Cl, "gamma" centre in the tripartite template does not seem to play the same role in monosaccharides and 4,1',6'-trichloro-4,1',6'-trideoxy-galacto-sucrose. The enhancement of sweetness in the disaccharide derivative is due to the enhanced hydrophobicity of the CH2Cl groups as well as to specific interactions with water. A sharp i.r. absorption characteristic of free hydroxyl is found in the spectra of most of the very sweet polyhydroxy compounds.