Cannizzaro’s reaction is given by aldehydes that do not have α− hydrogen, so it will not undergo the Cannizzaro reaction.
Cannizzaro’s reaction involves the formation of alcohol and salt of acid from aldehyde in presence of a strong base. Decarboxylation involves the release of CO2 from acid to give alkane. Aldehydes that do not have an α-hydrogen atom, undergo self oxidation and reduction (disproportionation) reaction on heating with concentrated alkali. In this reaction, one molecule of the aldehyde is reduced to alcohol while another is oxidised to carboxylic acid salt.