Carbohydrate Chem [Splst Period'l Rpt Vol 13] by J. Kennedy, et al.,

Show description

Sticzay, V. Kovic'ik, M. KulhAnek, and M. Tadra, Carbohydv. , 1979, 7 6 , 290. V. I. Krupenskii, Khim. , 1979, 96 (Chem. A b s . , 1979, 91, 141 125k). R. B. Taylor and V. C . Sood, J . Pharm. , 1978, 30, 510 (Chem. A b s . , 1979, 90, 72 397r). 72Similar condensations with other 0-dicarbonyl compounds led t o furan derivatives on acidic h y d r ~ l y s i s . % A study of the side-reactions in the acid hydrolysis of sucrose has shown that self-condensation of fructose is predominant. Fructosyl glucose is the major by-product with lesser amounts of trisaccharide ketoses, fructopyranosyl fructose, and i n u l ~ b i o s e .

Fujiwara and K. Arai, Carbohydr. , 1979, 69, 3 0 5 . J. Oehlke, Pharmazie, 1978, 33, 6 4 4 (Chern. A b s . , 1979, 90, 5 5 199k). 0 G ly c osid es 39 CO, H C&CH,NH, HOH,C I HO (73) OACOAC (74) 2-0- and 6-O~-D-mannopyranosyl-D-mannose have been synthesized by conventional routes. 181 Thioglycosides of 0-D-galactopyranose, 0-D-glucopyranose, a-D-mannohaving the aglycone pyranose, and 2-acetamido-2-deoxy-~-D-glucopyranose CH2CONHCH2CH(OMe)2 have been obtained by use of corresponding l-thiosugar derivatives.

D-glucopyranosides is readily effected by use of titanium tetrachloride, but replacement of the benzyl group at C-6 by acetate caused appreciable reduction in the reaction rates which suggested that the Lewis acid co-ordinated with both the ring and C-6 oxygen atoms prior t o ring opening. -D-glucopyranoside were studied at different alkali concentrations, and the reaction rates increased rapidly above 2M. '74 The thermal decomposition of a range of mono-, di-, and tri-saccharides related to the components of 4-0-methylglucuronoxylans was studied, and it was found that the thermal stability increased with increasing number of sugar units.