JEE Chemistry 2023 Question with Solution

Step-by-step solution

Standard Method

Under alkaline KMnO4 followed by acidic workup, the required major product corresponds to option (1).

Common mistakes

• Assuming alkaline $KMnO_4$ only affects one side chain. This is wrong because strong oxidation converts all oxidizable benzylic alkyl side chains on the aromatic ring to carboxylic acids. Check every benzylic substituent before choosing the product.

• Ignoring ester hydrolysis under alkaline conditions. This is wrong because the $-COOCH_3$ group can hydrolyze in basic medium and after acidic workup appear as $-COOH$. Include both oxidation and hydrolysis effects.

• Choosing the fused-ring rearranged product by focusing on skeletal appearance instead of reagent behavior. This is wrong because reagent-based prediction should dominate: alkaline permanganate favors oxidation of side chains, not arbitrary ring reconstruction.