Hydrolysis to carboxylic acid [acidic]

Hydrolysis to carboxylic acid [acidic] Definition:

 

When an ester is treated with aqueous acid (and heat) it is converted into a carboxylic acid.

 

 

Hydrolysis to carboxylic acids [acidic] Explained:

 

Esters can be hydrolyzed under acidic or basic conditions. These hydrolyses are nucleophilic substitution reactions that proceed by the addition-elimination mechanism.

The hydrolysis of esters in aqueous acid is a reversible equilibrium reaction that is driven to the right by using an excess of water. Thus, esters are cleaved to carboxylic acids and alcohols.

The mechanism of ester hydrolysis in acid consists of the addition of the nucleophile and the elimination of the leaving group:

The first part of the mechanism is the addition of water. The first step in acid-catalyzed ester hydrolysis is protonation of oxygen. This protonation makes the carbonyl group more electrophilic and ready for the nucleophilic attack by water. The positive charge is removed via deprotonation and formed a tetrahedral intermediate as a neutral addition product.

 

 

In the second part of the mechanism, the elimination of the leaving group (MeOH), the alkoxy group is converted to a better leaving group by protonation. This good leaving group is eliminated in the next step, and the final product (carboxylic acid) is formed by deprotonation.