Question

In the following reaction, X is an intermediate and Y is one of the end products. 

Which one of the following compounds is the end product Y? 

 

• A. (A)
• B. (B)
• C. (C)
• D. (D)

Hint:

In Grignard reactions, the carbonyl group is attacked by the Grignard reagent, forming an alkoxide intermediate that is later protonated to form the alcohol.

Answer 1

The Correct Option is D

To determine the end product Y in the given reaction, we will analyze the steps involved in the reaction mechanism.

The reaction involves the following components:

1. A ketone: \(\text{(CH}_3\text{)}_2\text{C=O}\)
2. A Grignard reagent: \(\text{C}_3\text{H}_7\text{MgI}\)
3. An acid workup: \(\text{H}^+\)

Step-by-step Reaction Mechanism:

1. The Grignard reagent \(\text{C}_3\text{H}_7\text{MgI}\) acts as a nucleophile and attacks the electrophilic carbon of the carbonyl group in the ketone.
2. This nucleophilic attack results in the formation of an alkoxide intermediate X.
3. The intermediate X then undergoes protonation during the acidic workup to form the alcohol product Y.

The reaction can be summarized as the conversion of a ketone to a tertiary alcohol after the addition of the Grignard reagent and subsequent acid workup.

Considering the options given:

• (A) is an ester.
• (B) is a secondary alcohol.
• (C) is a ketone.
• (D) is a tertiary alcohol.

Since the reaction mechanism leads to the formation of a tertiary alcohol, the correct answer is option (D).

Thus, the end product Y is a tertiary alcohol, as illustrated in option (D).