Question

The Cannizaro reaction is not given by

• A. trimethyl acetaldehyde
• B. acetaldehyde
• C. benzaldehyde
• D. formaldehyde

Answer 1

Answer: (B)

$\underset{\text{trimethyl acetaldehyde}}{C{H}_3-\underset{\stackrel{|}{C{H}_3}}{\stackrel{\underset{|}{C{H}_3}}{C}}-\stackrel{\underset{|}{H}}{C}=O}$
$\underset{\text{ acetaldehyde}}{H_{\alpha }-\underset{\stackrel{|}{H_{\alpha }}}{\stackrel{\underset{|}{H_{\alpha }}}{O}}-\stackrel{\underset{|}{H}}{C}=O}$

$\underset{\text{formaldehyde}}{H-\stackrel{\underset{|}{H}}{C}=O}$
Cannizzaro reaction is given by only those aldehydes which do not have $\alpha$-hydrogen atom. As such acetaldehyde will not give Cannizzaro reaction.