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JEE Main levelSingle correct optionDifficulty 2 of 3o2027

But-1-ene is hydrated with dilute $H X_{2} SO X_{4}$ . Which statement about the main product is correct?

AIt is butan-2-ol, obtained as a single (R) enantiomer
BIt is butan-1-ol, which is achiral
CIt is butan-2-ol, obtained as a meso compound
DIt is butan-2-ol, obtained as an optically inactive racemic mixture

Answer: D

Protonation gives the planar secondary cation

CH X_{3} CH X_{2} - CH X^{+} - CH X_{3}

. Water attacks either face equally, giving equal amounts of (R)- and (S)-butan-2-ol, a racemic mixture. A single stereocentre cannot give a meso compound.

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