Question

a. Which of the following reactions does not give the carbonyl product shown?

b. Which of the reactions that do not occur can be made to occur if an acid catalyst is added to the reaction mixture?

Short answer

a. 1,3,4,6,7,9 will not form the given product under such condition

b. 9 will form the shown product in presence of an acid catalyst

Step-by-step solution

(a) Reaction which does not give the carbonyl product shown

In reaction first, two equivalent of carboxylic acid leads to the formation of acetic anhydride only in the presence of P₂O₅ dehydrating agent only.

The acetic anhydride formed on the reaction of acyl chloride and the carboxylic acid, not by the two equivalents of carboxylic acid.

Hence, the given conditions are wrong.

(a) Reaction which does not give the carbonyl product shown

In the third reaction, the formation of acyl chloride occurs by the reaction of the amide with chloride ion but this is not possible because amide is not replaced by chloride ion.

The formation of the acyl chloride occurs on the reaction of the carboxylic acid with the thionyl chloride which leads to the reaction of the oxygen of the carboxylic with thionyl and acyl chloride formed.

(a) Reaction which does not give the carbonyl product shown

In the fourth reaction, the formation of amide is occur by reacting the carboxylic acid with amine which is not possible.

The right way of the formation of amide is the reaction of the acyl chloride with amide in which the chloride ion replaces by an amide ion and the acyl chloride is formed from carboxylic acid in reaction with thionyl chloride.

(a) Reaction which does not give the carbonyl product shown

In the seventh reaction shows the formation of acetic anhydride on the reaction of the amide with carboxylic acid which is a wrong reaction.

The acetic anhydride formation takes on a reaction with the acyl chloride with the carboxylic acid as shown below:

(a) Reaction which does not give the carbonyl product shown

In the ninth reaction, shows the formation of carboxylic acid in the reaction of amide in the presence of water which is a wrong reaction.

The formation of the two equivalents of a carboxylic acid is formed by reacting the acetic anhydride with water.

(b) Reaction occurred in presence of acid-catalyzed reaction

Reaction 9 occurs in the presence of the acid catalyst and the formation of the carboxylic acid occurs on reacting the acetic anhydride in reaction with the acid catalyst the two equivalent of the carboxylic acid are formed.