Cyclopentyl methyl ketone, C5H9-CO-CH3 (cyclopentyl = C5H9), is treated with CF3CO3H. The major product is

JEE Main levelSingle correct optionDifficulty 2 of 3ro097

Cyclopentyl methyl ketone, $C X_{5} H X_{9} - CO - CH X_{3}$ (cyclopentyl = $C X_{5} H X_{9}$ ), is treated with $CF X_{3} CO X_{3} H$ . The major product is

The secondary cyclopentyl group has a higher migratory aptitude than methyl, so it moves to oxygen. The ketone

C X_{5} H X_{9} - CO - CH X_{3}

becomes

CH X_{3} - CO - O - C X_{5} H X_{9}

, cyclopentyl ethanoate. The other ester would result from methyl migration.