Ch15 : ROH + R' X -> ROR' (Williamson ether synthesis)

Chapter 15: Alcohols, Diols and Thiols

Williamson Ether Synthesis

an alkoxide Nu attacks an alkyl halide to give the ether

Reaction type: Nucleophilic Substitution (S_N2)

Summary

Reagents : typically use Na metal as the base to generate the alkoxide then add the alkyl halide.
Since the reaction is S_N2, the halide should be methyl or primary.
Alkoxide character (primary, secondary or tertiary) is less important.
This reaction is suitable for either symmetrical or unsymmetrical ethers.
The method could also be used for cyclic ethers.

QUESTIONS
What reaction is likely to interfere if the halide is tertiary ?ANSWER
Can you write a balanced equation for the reaction of sodium metal with the alcohol ? ANSWER
What is the oxidation state and charge of the sodium metal ? ANSWER
What makes the methyl and primary halides most suitable ? ANSWER

Related Reactions

MECHANISM OF THE WILLIAMSON ETHER SYNTHESIS
The alkoxide functions as the nucleophile and attacks the electrophilic C of the alkyl halide displacing the bromide and creating the new C-O bond. This is an example of an S_N2 reaction.