The Williamson ether synthesis is an old, but still frequently encountered organic reaction, which provides ether products most often from alcohols and alkyl halides. Alkoxides, derived from alcohols and bases such as
sodium hydride or generated
in situ, and alkyl halides can react through S
N2 type mechanisms to give a variety of ether products. The reactivity is generally dependent on reaction the scope of the pertinent S
N2 reaction, with sterics being the dominant presiding factor.