Galactose 6-deoxy derivatives

A. C. Richardson and K. A. McLauchlan, 3-Amino-3-deoxy-derivatives of L-glucose, L-galactose and L-talose,/. Chem. Soc. (1962) 2499-2506. 

Benzylidene derivatives led to comparable amounts of 3- and 4-deoxy derivatives,26 whereas 4,6-O-benzylidene derivatives of glucose suffer deoxygenation at C-6 via the (less stabilized) primary radical, while the analogous galactose derivative led mainly to the 4-deoxy derivatives. The different regioselectivity has been explained considering the relative strain in the fused bicyclic structures.27... 

Lewisx (SLex, 26).76 The enzyme trans-sialidase transfers sialic acid to 0-3 of the galactose unit.77 Thus, the 3 -deoxy derivatives of the disaccharides would be useful for studying biological recognition processes. 

Springer and coworkers874 reported an extensive list of saccharides that were weakly inhibiting or noninhibiting. These included the 2-acetamido-2-deoxy derivatives of D-galactose, D-glucose, D-ribose, D-talose, and D-arabinose, 3,6-dideoxy-L- and -D-xy/o-hexose, L-lyxo-hexosulose, L-arabinose, D-fructose, and 2-deoxy-D-erythro-pentose. 

Replacement of a hydroxyl group by hydrogen yields a deoxy sugar. The derivative of ribose, deoxyribose, is a component of deoxyribonucleic acid (DNA). Similarly, deoxy derivatives of the two hexoses, galactose and mannose, occur as fucose and rhamnose, respectively, these being components of certain heteropolysaccharides. 

The synthesis of halodeoxy sugars has also been achieved by reaction of sugar phosphorodiamido and phosphonamido derivatives with alkyl halides (83). Heating equimolar amounts of 6-(tetraethylphosphoro-diamido)-l,2 3,4-di-0 isopropylidene-D-galactose with methyl iodide (and benzyl bromide) at 140°C. for 4 hours afforded the 6-deoxy-6-iodo (74b) (75%) and 6-bromo-6-deoxy (74c) (56%) derivatives, respectively. 

Deoxy-sugars. Part XVI. A Study of the Stabilities of Some Phosphoric Acid Derivatives of D-Galactose and 2-Deoxy-D-Gaiactose, A. B. Foster, W. G. Overend, and M. Stacey, /. Chem. Soc., (1951) 987-991. 

The structure of S10A has been investigated by Baddiley and coworkers.34,35 The polysaccharide is composed of D-galactose, 2-ace-tamido-2-deoxy-D-galactose, ribitol, and phosphate in the molar proportions 4 1 1 1. A hexasaccharide and its N-deacetylated derivative were obtained from S10A by treatment first with base and then... 

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