How does the Williamson ether synthesis make an ether from an alkoxide ion and an alkyl halide?

The Williamson ether synthesis is a versatile method for producing ethers by reacting an alkoxide ion with an alkyl halide.1

In this process, the alkoxide ion acts as a nucleophile and attacks the alkyl halide, effectively substituting the halide atom with an alkoxy (—O—R) group. To ensure the reaction proceeds successfully, the alkyl halide used must be unhindered—typically a primary alkyl halide—because if the halide is too sterically hindered, elimination reactions will compete with the desired substitution, reducing the yield of the ether. This method was devised in the 19th century by the English chemist Alexander Williamson.12