Williamson Ether Synthesis Practice Problems
For the synthesis of the following ether,
what is the best pair of alkoxide ion and alkyl halide to use?
Identify the set of alkyl halide and nucleophile that could be used as starting materials in the synthesis of the given ether.
(i) Illustrate how ethanol and cyclopentanol can be used to synthesize cyclopentyl ethyl ether via tosylation and subsequent Williamson ether synthesis.
(ii) Cyclopentyl ethyl ether can't be synthesized via bimolecular dehydration of the two alcohols. Explain why.
In the proposed synthesis of ethyl isopropyl ether shown below, first, ethanol is reacted with an acid to protonate the hydroxy group, and then sodium isopropoxide is added to displace water. What is wrong with the synthesis?
Synthesize 2-methoxypropane using (1) alkoxymercuration-demercuration and (2) Williamson ether synthesis.
Phenols have an acidic proton that can be deprotonated easily using sodium hydroxide or potassium hydroxide to give phenoxide anions. These ions can be used in the Williamson ether synthesis. Show how the following compound can be synthesized using 2-methylphenol, dimethyl sulfate, and other necessary reagents.
2-ethoxybutane can be made by either reacting butan-2-ol with sodium metal and then ethyl iodide, or by reacting butan-2-ol with tosyl chloride and pyridine and then with sodium ethoxide. When pure (S)-butan-2-ol of specific rotation −13.9º is subjected to the first procedure, 2-ethoxybutane with a specific rotation of −14.3º is obtained as the product. Propose a detailed mechanism, and predict the rotation of 2-ethoxybutane obtained using the second procedure.