Question

What is the name of the following reaction?
${\left( {C{H_3}CO} \right)_2}O + {C_6}{H_5}CHO\xrightarrow{{C{H_3}COONa}}{C_6}{H_5}CH = CH COOH + C{H_3}COOH$
A) Perkin reaction.
B) Friedel-craft reaction.
C) Hofmann reaction.
D) Tischenko reaction.

Answer 1

Hint: We know that Perkin reaction is the reaction between aromatic aldehydes and the aliphatic acid anhydride gives cinnamic acid derivatives. The Perkin reaction is an organic chemical reaction which is named after a scientist William Henry Perkin who discovers the reaction.

Complete step by step answer:Now, we see the details about the Perkin reaction.
Perkin reaction:
The Perkin reaction gives an alpha, beta-unsaturated aromatic acid through the aldol condensation of an aromatic aldehyde and an acid anhydride. The alkali salt of the acid is also present.
${\left( {C{H_3}CO} \right)_2}O + {C_6}{H_5}CHO\xrightarrow{{C{H_3}COONa}}{C_6}{H_5}CH = CH COOH + C{H_3}COOH$
Thus, the given reaction is an example of Perkin reaction. $\therefore $, option A is correct.
Let us discuss the Friedel-crafts reaction.
Friedel-crafts reaction:
An organic coupling reaction involving an electrophilic aromatic substitution that is used for the attachment of substituents to aromatic rings is called Friedel-crafts reaction. The two types of Friedel-Crafts reactions are the alkylation and acylation reactions.
Friedel-Crafts alkylation reactions is,

Friedel-Crafts acylation reactions is,

$\therefore $ option B is incorrect.
Let us discuss the Hofmann reaction.
Hofmann reaction:
An organic reaction in which primary amide is changed to primary amine with fewer number of carbon atoms.

$\therefore $, the option C is incorrect.
Now, we discuss the Tischenko reaction.
Tischenko reaction:
The disproportionation of aldehydes in the presence of an alkoxide is known as Tischenko reaction.

$\therefore $, the option D is incorrect.

And hence option A is correct.


Note:
We can use the Perkin reaction for the synthesis of phytoestrogenic stilbene resveratrol in the laboratory. Also we can use the Perkin reaction for synthesis cinnamic acids. We must know that the coumarin is the first synthesized substance by using the Perkin reaction. Therefore, we can synthesize coumarin by heating salicylic anhydride and acetic acid.