Answer: Pinacol rearrangement.
- A Kolbe reaction
- B Cannizzaro reaction
- C Pinacol rearrangement
- D Friedel-Crafts reaction
Correct answer: C. Pinacol rearrangement
Explanation: Pinacol rearrangement converts vicinal diols into carbonyl compounds via 1,2-shift.
The phenoxide ion's negative charge spreads into the aromatic ring through resonance, lowering its energy and making phenol give up its proton more easily; an alkoxide ion (from a plain alcohol) has nowhere to delocalise the charge, making alcohols far less acidic.
Concept context
Oxygen-containing organic compounds. Understand the acidic nature of phenols, reactions of alcohols (dehydration, oxidation, esterification), and properties of ethers. Includes industrial applications and named reactions.