||Chapter 15: Alcohols, Diols
Williamson Ether Synthesis
Reaction type: Nucleophilic Substitution
- Reagents : typically use Na metal
as the base to generate the alkoxide then add the alkyl halide.
- Since the reaction is SN2,
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.
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
What is the oxidation state and charge of the sodium metal ? ANSWER
What makes the methyl and primary halides most suitable ? ANSWER
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 SN2