Oxidative cleavage aromatic compounds

Some experiments were conducted to determine the influence of the solution pH. The catalytic oxidation of p-coumaric acid has been performed by increasing the initial pH from 3.5 to 7.5 and 11. Although the cleavage of the exocyclic double bond may be pH sensitive we obtained the same major intermediates which are the hydroxybenzaldehyde and the p-hydroxybenzoic acid molecules. The rate of oxidation of these aromatic compounds to ring opening compounds was higher when the initial pH was basic and yielded higher concentrations of maleic and fumaric acids. 

During the rotting of plant materials, different phenolic compounds can be identified (14, 16, 18, 28) as shown in Figure 1. These are aromatic compounds with side chains of one or three carbon atoms. They may be derived from the polymeric lignin by cleavage or oxidation reactions whereby the side chain is shortened. 

Oxidative cleavage of oximes.2 PDC is recommended for regeneration of ketones and aromatic aldehydes from the oximes (80-100% conversion). The rate of deoximation is increased by addition of 3A molecular sieves, but the yield of the carbonyl compound is lowered. 

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