Vanillin acetone oxidation

Vanillin 0.01-0.02% w/v in solutions, and syrups Sweet Light sensitive, and slowly oxidizes in moist air Incompatible with acetone. Alkaline solutions turn brown-colored. 1 100 in water, 1 2 in ethanol... 

The choice of liquid phase can affect the course of ozonation. This has been shown with phenylindenes by Miura et al. (1985) and with lignin models by Kratzl et al. (1976), who found that 4-methylveratrole gave a higher yield of dimethyl -methyl-cis,cis-muconate in 45% aqueous acetic acid than in dichloromethane and that the yield of dimethyl oxalate from acetoveratrone was markedly dependent on the solvent. Eriksson and Gierer (1985) found that in methanol the benzene ring of vanillin is cleaved (albeit only very slowly, after acetalization has occurred), but that in nonprotic solvents, such as acetone, the initial reaction is oxidation of the aldehyde function to a carboxyl group. 

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