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NEET levelSingle correct optionDifficulty 1 of 3o3003

Optically active (S)-3-chloro-3-methylhexane is hydrolysed in aqueous acetone by the SN1 mechanism. The 3-methylhexan-3-ol obtained is

  1. Aonly the (R) alcohol, formed with complete inversion
  2. Bonly the (S) alcohol, formed with complete retention
  3. Ca meso compound
  4. Dan (almost) racemic mixture of the (R) and (S) alcohols

Answer: D

The slow step gives a planar, sp2 hybridised tertiary carbocation. Water can attack either face of this cation with nearly equal probability, so both enantiomeric alcohols are formed in nearly equal amounts and the product is (almost) racemic.
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