Disproportionation is a specific type of redox reaction in which a species is simultaneously reduced and oxidised to form two different products.he oxidation state of oxygen is -1/2 in the superoxide free radical anion, -1 in hydrogen peroxide and 0 in dioxygen. 1  In the Cannizzaro reaction, an aldehyde is converted into an alcohol and a carboxylic acid. 2  In the related Tishchenko reaction, the organic redox reaction product is the corresponding ester.