Sugars periodic acid degradation

In Summary Oxidative cleavage with periodic acid degrades the sugar backbone to formic acid, formaldehyde, and CO2. The ratio of these products depends on the structure of the sugar. 

As a preparatory method, oxidation with periodic acid is of particular importance for the preparation of short-chain sugars. For example, 2,3-0-benzylidene-D-arabitol (I) consumes one mole of periodic acid and yields 2,3-0-benzylidine-D-threose (II) which can be converted to a crystalline isopropylidene derivative 226), The oxidation of aldoses by one mole of lead tetraacetate in acetic acid will cause degradation to aldoses containing one less carbon thus, D-arabinose and D-lyxose have been prepared in yields of more than 35% from D-glucose and D-galactose, respectively 227), The... 

The methods for oxidation of sugars discussed so far leave the basic skeleton intact. A reagent that leads to C-C bond rupture is periodic acid, HIO4. This compound oxidatively degrades vicinal diols to give carbonyl compounds. 

The incorporation of [2-14C]pyruvate and [l-14C]acetate into sugars 17 and 18 was investigated.27 Oxidation of the methyl glycosides of sugar 17 with periodate yielded acetaldehyde from the 1-hydroxyethyl branch. The acetaldehyde (2,4-dinitrophenyl)hydrazone was further oxidized by Kuhn-Roth oxidation to acetic acid, which was degraded by the Schmidt reaction to methylamine and carbon dioxide. Periodate oxidation of the methyl glycosides of sugar 18 produced acetic acid from the C-acetyl branch. The acetic acid was isolated, and purified as 1-acetamidonaphthalene. 

Sometimes, it is more feasible, however, to degrade periodate-oxidized polysaccharides so that unattacked residues are split off as free, reducing sugars. This can be achieved by a graded hydrolysis of the polyaldehyde with sulfurous acid. The conditions for an optimum yield of the desired products must be carefully chosen. ... 

However, Head showed that glyoxal is produced by the treatment of both oxycellulose and periodate-oxidized methyl fl-cellobioside (121) with alkali. The other theory was that of Haskins and Hogshead, based on the p-alkoxycarbonyl elimination mechanism of Isbell for the formation of saccharinic acids on treatment of sugars with alkali. They suggested that fission of the C5—O bond would yield glyoxal and n-erythrose. Recent work has indicated that the degradation is, indeed, based on a jS-alkoxycarbonyl elimination, but the products are different from those postulated above. 

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