Question

Reaction of Grignard reagent, C₂H₅MgBr with C₈H₈O followed by hydrolysis gives compound "A" which reacts instantly with Lucas reagent to give compound B, C₁₀H₁₃Cl. The Compound B is : 

• A. A
• B. B
• C. C
• D. D

Hint:

Lucas Test: 3° alcohols react instantly (turbidity), 2° in 5 mins, 1° do not react at room temp.

Answer 1

The Correct Option is D

Let's solve this problem step-by-step: 

1. The Grignard reagent, \(C_2H_5MgBr\), reacts with \(C_8H_8O\) (which is benzaldehyde, \(C_6H_5CHO\)) followed by hydrolysis. This forms an alcohol because Grignard reagents react with aldehydes to form secondary alcohols. The reaction is: 
   
   \(C_2H_5MgBr + C_6H_5CHO \rightarrow C_6H_5CH(OH)C_2H_5\) (compound "A")
2. Compound "A" (a secondary alcohol) reacts instantly with Lucas reagent (a mixture of concentrated hydrochloric acid and zinc chloride) to form the corresponding alkyl chloride. This reaction is characteristic of secondary alcohols. Thus, we get: 
   
   \(C_6H_5CH(OH)C_2H_5 + HCl \rightarrow C_6H_5CH(Cl)C_2H_5\) (compound "B")
3. The molecular formula of compound B is given as \(C_{10}H_{13}Cl\). This corresponds to a structure where we have an ethyl group and a chlorine attached to a benzene ring.
4. Based on the options provided, we need to match the structure \(C_6H_5CH(Cl)C_2H_5\) with the correct compound. Option D matches this structure:
5. Therefore, the correct answer is Option D.