Question

Name the functional group for which Cannizzaro reaction is not given.

Answer 1

Cannizzaro reaction:

• Cannizzaro reaction is basically known as one type of redox reaction.
• In this two molecules of carbonyl compounds undergo disproportionation reaction, in which one molecule of Aldehyde gets oxidized to form Carboxylic acid whereas the other molecule undergoes reduction to produce an Alcohol.
• The Cannizzaro’s reaction can be given as :

The functional group which does not show Cannizzaro reaction :

• Cannizzaro’s reaction is generally given by those carbonyl compounds that do not have α− Hydrogen.
• The $\mathrm{\alpha }-\mathrm{H}$ is known as the atom attached to $\mathrm{\alpha }-\mathrm{C}$ of the molecule which is the Carbon atom just adjacent to the Carbon bearing functional group.
• Hence, we can say those molecules or aldehydes that will have $\mathrm{\alpha }-\mathrm{H}$ will not give a Cannizzaro reaction.
• Example : In case of Acetaldehyde $(\mathrm{C}{\mathrm{H}}_3-\mathrm{CHO})$, there exist a $\mathrm{\alpha }-\mathrm{H}$ bearing $\mathrm{\alpha }-\mathrm{C}$, so it will not undergo cannizzaro reaction.

Hence, carbonyl compounds containing a $\mathrm{\alpha }-\mathrm{H}$ ,will not give cannizzaro reaction.