Oxidation of sodium salts of alduronic and glyculosonic acids by sodium peroxide

Influence of Alkaline Treatment and Alkaline Peroxide Bleaching of Aspen Chemithermomechanical Pulp on Dissolved and Colloidal Substances

“…Similar results were also observed by Thornton et al and Pranovich et al, who treated spruce TMP with alkali and alkaline peroxide. , Native pectic substances, some of which are methyl esterified, are primarily comprised of galacturonic acid units . Methylated pectic substances can be degraded in alkaline conditions by β-elimination reactions which occur together with demethylation. , Polygalacturonic acids can be decomposed by hydrogen peroxide, which generates low-molar-mass acids and carbon dioxide . Polygalacturonic acids released during alkaline peroxide bleaching of TMP have a much lower molar mass than that released during alkaline treatment .…”

“…17,34 Polygalacturonic acids can be decomposed by hydrogen peroxide, which generates low-molar-mass acids and carbon dioxide. 35 Polygalacturonic acids released during alkaline peroxide bleaching of TMP have a much lower molar mass than that released during alkaline treatment. 36 The release of glucuronic acids during alkaline peroxide bleaching was probably mainly induced by the cleavage of bonds between xylose units and 4-O-methylglucuronic acids due to the attack of hydroxyl radical under alkaline conditions.…”

The Ruff degradation: a review of previously proposed mechanisms with evidence that the reaction proceeds by a Hofer–Moest-type reaction

“…Their proposed mechanism involves oxidation of the carbon atom adjacent to the carboxylate group to a keto group (Chart 5). While a-keto acids are known to decarboxylate in the presence of hydrogen peroxide, 68 retains its a-proton and the successful degradations of saccharinic acids rule out an a-keto acid pathway. Vás-quez-Vivar et al 70 concluded that decarboxylation of a-keto acids in a Fe(II) + H 2 O 2 system follows two pathways (Chart 6), both of which produce acids rather than aldehydes.…”

Organocatalytic Conjugate Addition of Formaldehyde N,N-Dialkylhydrazones to β,γ-Unsaturated α-Keto Esters

“…Compounds 8 are versatile 1,4-dicarbonyl compounds that can be transformed into nitriles 16 by applying a simple, racemization-free oxidative cleavage of the hydrazone moiety by magnesium monoperoxyphtalate hexahydrate (MMPP·6H 2 O) (Scheme ). Additionally, ozonolytic cleavage of 8a afforded an unstable intermediate that was further oxidized by a HCO 2 H/H 2 O 2 mixture and treated with SOCl 2 /MeOH to obtain the succinate derivative 17 resulting from deoxidative decarboxylation . Comparison of its optical rotation with literature data was used for the assignment of its absolute configuration and that of the parent adduct 8a .…”