Question

Identify \( Z \) in the following reaction.

• A. A
• B. B
• C. C
• D. D

Hint:

In esterification reactions, phenols react with alkyl or acyl halides to form esters, with pyridine acting as a catalyst.

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
The reaction involves phenol (\( \text{Ar-OH} \)) reacting with an acyl chloride (\( \text{R-COCl} \)) in the presence of pyridine. This is a standard acylation reaction.
Step 2: Key Formula or Approach:
Acylation of phenols leads to the formation of esters. The oxygen atom of the phenol acts as a nucleophile and attacks the carbonyl carbon of the acyl chloride, displacing the chloride ion.
Step 3: Detailed Explanation:
Phenol (\( \text{Ar-OH} \)) reacts with an acid chloride (\( \text{R-COCl} \)) to produce an ester (\( \text{R-COOAr} \)) and hydrochloric acid (\( \text{HCl} \)).
Pyridine is used as a base to neutralize the \( \text{HCl} \) formed, which shifts the equilibrium toward the products.
Reaction: \( \text{Ar}-\text{OH} + \text{Cl}-\text{C}(=\text{O})-\text{R} \xrightarrow{\text{Pyridine}} \text{R}-\text{C}(=\text{O})-\text{OAr} + \text{HCl} \).
The product \( \text{Z} \) is an aryl ester where the acyl group (\( \text{R-CO-} \)) is attached to the phenolic oxygen.
Step 4: Final Answer:
The correct structure for \( \text{Z} \) is \( \text{R} - \text{C}(=\text{O}) - \text{OAr} \), which corresponds to option (C).