MolSynapsequestion bank
MolSynapse / Question bank / Organic Reaction Mechanisms III: Nucleophilic Substitution / SN1 vs SN2: substrate, nucleophile, solvent, leaving group
NEET levelSingle correct optionDifficulty 1 of 3o3117

(S)-Butan-2-ol is converted into 2-bromobutane by phosphorus tribromide. Which statement describes the product correctly?

  1. A(R)-2-bromobutane, formed with inversion of configuration
  2. B(S)-2-bromobutane, formed with inversion of configuration
  3. C(S)-2-bromobutane, formed with retention of configuration
  4. Dracemic 2-bromobutane, formed through a free carbocation

Answer: A

converts the OH into , a good leaving group, and the liberated bromide then attacks the carbon by SN2 from the back. Inversion occurs, and since the priority order (halogen or O, then , , H) is unchanged, S becomes R.
Practice Organic Reaction Mechanisms III: Nucleophilic Substitution More on SN1 vs SN2: substrate, nucleophile, solvent, leaving group
Previous questionNext question

More questions on SN1 vs SN2: substrate, nucleophile, solvent, leaving group