Glyoxylic acid, ozonolysis

DuPont has developed a process for the manufacture of glyoxylic acid by aerobic oxidation of glycolic acid (Fig. 2.33) mediated by whole cells of a recombinant methylotrophic yeast (Gavagnan et al, 1995). The glycolic acid raw material is readily available from the acid-catalysed carbonylation of formaldehyde. Traditionally, glyoxylic acid was produced by nitric acid oxidation of acetaldehyde or glyoxal, processes with high E factors, and more recently by ozonolysis of maleic anhydride. 

Chemical/Physical. Ozonolysis of acetic acid in distilled water at 25 °C yielded glyoxylic acid which oxidized readily to oxalic acid before undergoing additional oxidation producing carbon dioxide. Ozonolysis accompanied by UV irradiation enhanced the removal of acetic acid (Kuo et al, 1977). 

The reactivity of double bonds has been used in organic industrial chemistry and pharmaceutical applications. For example, glyoxylic acid is produced by ozonolysis of dimethyl maleate (Scheme 2). 

Preparative Methods ozonolysis of 8-Phenylmenthyl Acrylate, NaOAc-catalyzed elimination of nitrite ion from nitrate esters, and direct esterification with glyoxylic acid. ... 

The ozonolysis of y-pyrone yields mesoxal dialdehyde (0.03 mole), glyoxylic acid (0.12 mole), glyoxal (0.12 mole), and formic acid (3.1 moles). 

In the ozonolysis of 3-methyl-y-pyrone and of tetramethyl-y-pyrone, scission products are formed which are characteristic for polar structures. In the ozonolysis of 2,3,6-dimethyl-y-pyrone particularly interesting results were obtained. The following characteristic scission products have been isolated pyruvic acid (0.11 mole), dimethylglyoxal (0.07 mole), methylglyoxal (0.08 mole), glyoxylic acid (0.11 mole), and acetic acid (1.85 moles). This means that the trimethyl-y-pyrone reacts according to mesomeric polar structures. 

---