Key Idea Cannizzaro reaction takes place in those aldehydes that do not have an alpha -hydrogen. It proceed via disproportionation reaction. The given reaction is named as Cannizzaro reaction. In this reaction, aldehydes that do not have an alpha -hydrogen atom undergoes self oxidation and reduction (dis proportionation) reaction on heating with concentrated alkali. In this reaction, one − CHO group of the aldehyde is reduced to alcohol while another is oxidised to carboxylic acid salt.