Tertiary alcohol in Z prevents oxidation by acidified KMnO4

Steps:

• Acidified KMnO4 oxidizes primary alcohols to carboxylic acids and secondary alcohols to ketones, but tertiary alcohols remain unreacted.
• Identify the alcohol type in each option by examining the carbon bearing the OH group.
• Option A: C2 is attached to C1 (carboxy), CH3, CH2CH3, and OH—tertiary, no reaction.
• Options B and D: CH2OH group—primary, reacts; option C: CH(OH)CH3 group—secondary, reacts.
• The salt Mr confirms molecular size, but oxidation test identifies A as matching no reaction.

Why A is correct:

• Tertiary alcohols lack a hydrogen on the OH-bearing carbon, preventing formation of a carbonyl group per oxidation mechanism.

Why the others are wrong:

• B: Primary alcohol oxidizes, decolorizing KMnO4.
• C: Secondary alcohol oxidizes to ketone, decolorizing KMnO4.
• D: Primary alcohol oxidizes, decolorizing KMnO4.

Final answer: A