Question

Benzyl alcohol and sodium benzoate is obtained by the action of sodium hydroxide on benzaldehyde. This reaction is known as
A. Perkin reaction
B. Cannizzaro’s reaction
C. Sandmeyer’s reaction
D. Claisen reaction

Answer 1

Hint: We know that Cannizarro reaction is the disproportionation of two non-enolizable aldehydes in the presence of a base to give a primary alcohol and a carboxylic acid.

Complete step by step answer:
Benzyl alcohol and sodium benzoate is obtained by the reaction of benzaldehyde with sodium hydroxide. This is an example of Cannizzaro reaction. In this reaction, primary alcohol and sodium salt of carboxylic acid are obtained. The reaction can be shown as below:

Hence, the correct option is B.

Additional Information
Let’s discuss the other three reactions given in options.

Option A is the Perkin reaction. In the Perkin reaction, an aromatic aldehyde and acid anhydride undergoes aldol condensation in presence of alkali salt of the acid to produce $\alpha ,\beta $-unsaturated aromatic acid.


Option B is the Sandmeyer reaction. A chemical reaction that produces aryl halides from aryl diazonium salts using copper salts as catalyst is termed as Sandmeyer's reaction. This reaction is used in transformation of benzene like trifluoromethylation, cyanation etc.


Option C is the Claisen reaction. The Claisen condensation is a reaction in which formation of carbon–carbon bond occurs between one ester and one carbonyl compound or between two esters in the presence of a strong base to form a $\beta $-keto ester or a $\beta $-diketone.

Note:
It is to be noted that Cannizzaro reaction is shown by only those aldehydes which do not have an alpha hydrogen atom. Alpha hydrogen is that hydrogen atom bonded to an alpha carbon.