Williamson Ether Synthesis is the most important laboratory method for preparing symmetrical and unsymmetrical ethers.

• Reaction: $R-O^{-}N{a}^{+}+R^{\prime }-X\to R-O-R^{\prime }+NaX$
• Mechanism: It follows an $S_{N}2$ pathway, where the alkoxide ion serves as a nucleophile attacking the alkyl halide.
• Constraint: To achieve high yields, especially for unsymmetrical ethers, the alkyl halide ($R^{\prime }-X$) should be primary ($1^{\circ }$). Secondary or tertiary halides primarily undergo elimination ($E2$) to form alkenes due to the basic nature of the alkoxide.