Question

Draw a stepwise mechanism for the following reaction.

Short answer

Answer

Formation of the final product

Step-by-step solution

Step-by-Step SolutionStep 1: The intramolecular esterification

The intramolecular esterification takes place from the and hydroxy carboxylic acids. It occurs in the presence of a strong acid and forms five or six-membered lactones.

During this reaction, the acid protonates the carbonyl group and causes the intramolecular ring closure resulting in the formation of lactones.

The stepwise mechanism of the given reaction

• The first step involves the protonation of the carboxylic acid group followed by the removal of a proton.

First step

• The second step is the ring closure by the nucleophilic attack of the -OH group on the carbonyl carbon.

Second step

• The next step is the protonation of the alcohol group.

Third step

• Finally, a proton is removed by the group:

Formation of the final product