Question

An organic compound \( B \) is formed by the reaction of ethyl magnesium iodide with a substance \( A \), followed by treatment with dilute aqueous acid. Compound \( B \) does not react with PCC or PDC in dichloromethane. Which of the following is a possible compound for \( A \)?

• A. \( \text{CH}_3\text{COOH} \)
• B. \( \text{CH}_3 \text{CHO} \)
• C. \( \text{CH}_3 \text{COOH} \)
• D. \( \text{H}_2\text{C=O} \)

Hint:

Grignard reagents react with carbonyl compounds to form alcohols, and PCC or PDC can oxidize primary alcohols to aldehydes but not secondary alcohols.

Answer 1

The Correct Option is A

Step 1: Reaction with Grignard reagent.
The reaction of ethyl magnesium iodide (a Grignard reagent) with a carbonyl compound like an aldehyde or ketone forms an alcohol. The fact that \( B \) does not react with PCC or PDC suggests that \( B \) is an alcohol, specifically a secondary alcohol.

Step 2: Conclusion.
The correct compound \( A \) is acetic acid, corresponding to option (1).