Question

The conversion of Benzaldehyde into benzyl alcohol takes place by:
(A)Fitting reaction
(B) Wurtz-fittig reaction
(C)Wurtz reaction
(D)Cannizzaro’s reaction

Answer 1

Benzaldehyde is an organic compound with formula ${C_7}{H_6}O$. It is the simplest aromatic aldehyde and one of the most industrially useful. It is a colourless liquid with an almond like odor. Benzaldehyde does not contain any $\alpha$-hydrogen and thus can undergo cannizzaro reaction easily.

Complete step by step answer:
Let us firstly discuss all the reactions given. First of all is a fitting reaction. When $2$ moles of aryl halide are reacted with sodium $\left( {Na} \right)$ metal in presence of dry ether which leads to the formation of diphenyl. This reaction is known as a fitting reaction.

The next reaction given is a Wurtz fittig reaction. In this reaction alkyl halide is reacted with aryl halide and sodium $\left( {Na} \right)$metal in presence of dry ether which leads to the formation of alkyl benzene.

The wurtz reaction:- In this reaction, $2$ moles of alkyl halide is reacted with sodium $\left( {Na} \right)$ metal in presence of dry ether which leads to formation of alkane.
${R_1} - X + 2Na + X - {R_2}\xrightarrow{{{\text{dry ether}}}}{R_1} - {R_2} + 2NaX$
The next type of given reaction is cannizzaro reaction. It is given by those carbonyl compounds in which $\alpha -$hydrogen is absent. It is a disproportionation reds reaction
In the Benzaldehyde, $\alpha$-hydrogen is absent. so the $2$ moles of Benzaldehyde undergo cannizzaro reaction to given benzyl alcohol

Hence conversion of Benzaldehyde into benzyl alcohol takes place by cannizzaro reaction
Hence option (D) is the correct answer.

Note:
Cannizzaro reaction can be done also with $KOH$. The base used here should be Concentrated. The Cannizzaro process is a redox reaction involving transfer of a hydride from one substrate molecule to the other.