Question

An alcohol X (C\(_5\)H\(_{12}\)O) when reacted with conc. HCl and anhydrous ZnCl\(_2\), produces turbidity instantly. The alcohol X can be prepared from which of the following reactions?

• A. Reduction of 2-pentanone with NaBH\(_4\)
• B. Reaction of isopropyl magnesium bromide with ethanol
• C. Reaction of ethyl magnesium bromide with propanal
• D. Acid catalyzed hydration of 2-methyl-1-butene

Hint:

Tertiary alcohols react instantly with Lucas reagent due to rapid formation of carbocations.

Answer 1

The Correct Option is D

The Lucas test (reaction with HCl/ZnCl\(_2\)) gives instant turbidity for tertiary alcohols. The acid-catalyzed hydration of 2-methyl-1-butene forms 2-methyl-2-butanol, a tertiary alcohol, which reacts instantly. Other options do not form tertiary alcohols.