Advanced Topic 799 of 1102 Organic Chemistry
Williamson Ether Synthesis
An alkoxide reacts with an alkyl halide via SN2 to form an ether.
In-depth explanation of Williamson Ether Synthesis
The Williamson ether synthesis prepares an ether by reacting a metal alkoxide, RO-, with a primary alkyl halide, R'X, by an SN2 substitution, giving ROR'. The alkoxide is prepared by treating an alcohol with a strong base such as sodium hydride. Because the reaction is SN2, it works best with primary halides, while secondary and tertiary halides give elimination instead. This method is the most reliable way to make unsymmetrical ethers, in which the two carbon groups differ.
Going deeper: Williamson Ether Synthesis
Key ideas: An alkoxide (RO- from alcohol plus Na or NaH) attacks a primary alkyl halide by SN2, giving an ether. For unsymmetrical ethers choose the combination where the halide is methyl or primary and the bulky group sits on the alkoxide: tert-butyl methyl ether comes from tert-butoxide plus methyl iodide, not from methoxide plus tert-butyl chloride. Phenoxide with an alkyl halide makes aryl alkyl ethers.
Common mistakes and connections: Students use tertiary halides, which eliminate to alkene instead. Another error is thinking aryl halides will react with alkoxides in SN2; they do not. Links to SN2, E2 competition, ether nomenclature and intramolecular variants forming epoxides.
Visualization of Williamson Ether Synthesis
An alkoxide attacks a primary alkyl halide in an SN2 step, forming the C-O-C ether bond with inversion at carbon. The interactive lesson shows this as a live animation or chart.
Worked example and use case
Sodium methoxide reacts with bromoethane to give methyl ethyl ether, CH3ONa plus CH3CH2Br giving CH3OCH2CH3.
Frequently asked questions about Williamson Ether Synthesis
What is Williamson Ether Synthesis?
An alkoxide reacts with an alkyl halide via SN2 to form an ether.
Is Williamson Ether Synthesis a beginner, intermediate or advanced topic?
Williamson Ether Synthesis is a advanced topic in Organic Chemistry. It builds on beginner and intermediate topics, so review those first if needed.
What should I learn before Williamson Ether Synthesis?
Study these earlier topics in Organic Chemistry first: Ethanol Production, Phenols, Ethers.
What comes after Williamson Ether Synthesis?
The next topics in Organic Chemistry are Aldehydes and Ketones.
Can I practise Williamson Ether Synthesis with quizzes?
Yes. The interactive lesson includes a self-check question on Williamson Ether Synthesis, and the Organic Chemistry quiz draws on every topic in this area.
Where Williamson Ether Synthesis fits in Organic Chemistry
Williamson Ether Synthesis is topic 71 of 148 in Organic Chemistry.