Lesson eLearning

In the Williamson ether synthesis, which of the following statements is true?

medium MCQ 2 marks Class 12 · Chemistry · Alcohols Phenols and Ethers
  1. A. The reaction proceeds efficiently when both reactants are tertiary alkyl halides.
  2. B. A primary alkyl halide reacts best with a primary alkoxide to give an ether.
  3. C. Secondary alkyl halides give higher yields than primary ones due to better leaving groups.
  4. D. The reaction is favored in strongly acidic medium.
Answer
B. A primary alkyl halide reacts best with a primary alkoxide to give an ether.

The correct answer is B. A primary alkyl halide reacts best with a primary alkoxide to give an ether. — Therefore, statement B correctly describes the optimum combination for the Williamson synthesis.

Step-by-step solution

  1. Recall that the Williamson ether synthesis proceeds via an reaction between an alkoxide ion and an alkyl halide.
  2. An reaction requires a substrate with little steric hindrance; primary alkyl halides satisfy this condition.
  3. If the alkyl halide is tertiary, elimination () dominates, giving alkenes instead of ethers.
  4. Secondary alkyl halides give slower rates and compete with elimination, reducing yields.
  5. The reaction must be carried out in a non‑protic, aprotic solvent; acidic conditions would protonate the alkoxide.
  6. Therefore, statement B correctly describes the optimum combination for the Williamson synthesis.
Common mistake: Choosing option A, believing tertiary halides work well (they lead to elimination)

Concept tested: Williamson ether synthesis

Published · How this solution was prepared and checked

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