Aldehydes which have no α-H atom give Cannizzaro's reaction, (CH3)3C−CHO does not contain α-H atom, hence it will give Cannizzaro reaction.

What type of aldehyde can go Cannizzaro reaction?

What type of aldehydes undergo Cannizzaro's reaction? Aldehydes which do not have an alpha hydrogen atom, undergo self-oxidation and reduction reaction on treatment with concentrated alkali. In this reaction, one molecule of the aldehyde is reduced to alcohol while another is oxidized to carboxylic acid salt.

Which aldehydes do not give Cannizzaro reaction?

Here we see that only Acetaldehyde contains an α− hydrogen so it will not undergo the Cannizzaro reaction.