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NEET levelSingle correct optionDifficulty 1 of 3g3060

The alpha hydrogens of propanone () are much more acidic than those of propane mainly because

  1. Apropanone forms hydrogen bonds with the base
  2. Bthe C=O group is non-polar
  3. Cthe methyl groups of propanone are strongly electron releasing
  4. Dthe enolate ion formed is stabilised by delocalisation of the negative charge onto oxygen

Answer: D

Loss of an alpha proton from propanone gives , which is a resonance hybrid with the charge shared between carbon and the electronegative oxygen. This delocalisation stabilises the conjugate base and so raises the acidity. Propane gives only a localised, unstabilised carbanion.
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