Question

Which of the following compounds cannot be prepared by Williamson's synthesis?

• A. \(\text{C}_{6}\text{H}_{5}\text{OCH}_{2}\text{CH}_{3}\)
• B. \(\text{CH}_{3}\text{CH}_{2}\text{O CH}_{2}\text{CH}_{3}\)
• C. \((\text{CH}_{3})_{3}\text{C-O-CH}_{2}\text{CH}_{3}\)
• D. \((\text{CH}_{3})_{3}\text{C-O-C(CH}_{3})_{3}\)

Hint:

Williamson synthesis is an SN2 reaction, which fails with a tertiary alkyl halide.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept
Williamson synthesis uses an alkoxide and a primary alkyl halide in an \(S_N2\) reaction.

Step 2: Limitation
A tertiary alkyl halide gives elimination to an alkene instead of substitution.

Step 3: Check the options
Options A, B and C can all be made using a primary halide such as ethyl halide with a suitable alkoxide or phenoxide. Option D, di-tert-butyl ether, would need a tertiary halide on one side, so it cannot be prepared.

Final Answer:
Di-tert-butyl ether cannot be prepared by Williamson synthesis. \[ \boxed{\text{(D) }(\text{CH}_{3})_{3}\text{C-O-C(CH}_{3})_{3}} \]