Carboxylic acids peroxy acid oxidation

Unlike ketones, aldehydes are easily oxidized to carboxylic acids by common oxidants such as bleach (sodium hypochlorite), chromic acid, permanganate, and peroxy Oxidation acids. Aldehydes oxidize so easily that air must be excluded from their containers to q-P A (jehvdeS avoid slow oxidation by atmospheric oxygen. Because aldehydes oxidize so easily, mild reagents such as Ag20 can oxidize them selectively in the presence of other oxidizable functional groups. 

A number of aryl-eubst-ituted ethylene oxidea have been exposed to tlie action of carboxylic adds during the peroxy acid oxidation of olefane. Among these (Bq. 763) may be cited -metbylstyrwie tM... 

Carboxylic acids decarboxylate in oxidizing cumene at 80°C, whereas, in the absence of oxygen, they decarboxylate only above 300° C [208], The reaction of peroxy radicals with carboxylic groups was suggested to account for C02 formation, viz. 

In this most likely multistage reaction, the carboxylic acids and gaseous oxidative products are produce by peroxy radicals. Characteristic of the radiation-induced oxidation is the significant peld of carboxylic adds and low yield of hydroperoxides. The chain reaction involving hydroperoxides may be more important during the thermal oxidation. 

Functional groups that stabilize radicals would be expected to increase susceptibility to autoxidation. This is illustrated by two cases that have been relatively well studied. Aldehydes, in which abstraction of the aldehyde hydrogen is fecile, are easily autoxidized. The autoxidation initially forms a peroxycarboxylic acid, but usually the corresponding carboxylic acid is isolated because the peroxy acid oxidizes additional aldehyde in a... 

The analytical method described is also used in following the consumption of peroxybenzoic acid or other peroxy acids during an oxidation reaction it has also been used in determining the conversion of other carboxylic acids to peroxy acids when solvent extraction has been used in the isolation. 

Oxidation, of acids to peroxy acids by hydrogen peroxide, 43, 96 of alkylarenes to aromatic carboxylic acids, 43, 80... 

Peroxy acids resemble carboxylic acids in structure, possessing just one additional oxygen atom. Peroxy acids are not very acidic, but they are used as strong oxidizing agents. Common examples of peroxy acids are ... 

Acidic products result from further oxidation of aldehydes (or ketones), again by a radical process. Oxidation of an aldehyde to a carboxylic acid in the presence of air involves a peroxy acid (compare peroxyacetic acid. Section 8.1.2). Finally, a reaction between the peroxy acid and a molecule of aldehyde yields two carboxylic acid molecules this is not a radical reaction, but is an example of a Baeyer-Villiger oxidation. Baeyer-Villiger... 

Oxidation of Carboxylic Acids to Peroxy Acids Peroxy-de-hydroxy-substitiition... 

The oxidation of carboxylic acids with H202 and an acid catalyst is the best general method for the preparation of peroxy acids.450 The most common catalyst for aliphatic R is concentrated sulfuric acid. The reaction is an equilibrium and is driven to the right by removal of water or by the use of excess reagents. For aromatic R the best catalyst is methanesulfonic acid, which is also used as the solvent. 

Oxidative hydrolysis transforms the intermediate ozonide into ketone(s) and/or carboxylic acid(s) in good yields. H202 in water, in sodium hydroxide solution, or in formic acid is the best proven oxidant.582,584,592 Peroxy acids and silver oxide are also employed. Rearrangement and overoxidation may be undesirable side-reactions. A simple two-step ozonation in MeOH yields methyl esters without added oxidizing agent.627... 

---