Editing Williamson ether synthesis (section)

==Mechanism==
The Williamson ether reaction follows an S<sub>N</sub>2 (bimolecular nucleophilic substitution) mechanism. In an S<sub>N</sub>2 reaction mechanism there is a backside attack of an electrophile by a nucleophile and it occurs in a concerted mechanism (happens all at once). In order for the S<sub>N</sub>2 reaction to take place there must be a good [[leaving group]] which is strongly electronegative, commonly a halide.<ref>{{Cite book|last=Wade|first=Leroy|title=Organic Chemistry|publisher=Pearson|year=2017|isbn=9780321971371|pages=261–274}}</ref>

In the Williamson ether reaction there is an alkoxide ion (RO<sup>−</sup>) which acts as the nucleophile, attacking the electrophilic carbon with the leaving group, which in most cases is an alkyl tosylate or an alkyl halide. The leaving site must be a primary carbon, because secondary and tertiary leaving sites generally prefer to proceed as an [[elimination reaction]]. Also, this reaction does not favor the formation of bulky ethers like di-tertbutyl ether, due to steric hindrance and predominant formation of alkenes instead.<ref>{{Cite book|last=Wade|first=Leroy|title=Organic Chemistry|publisher=Pearson|year=2017|isbn=9780321971371|pages=682–683}}</ref>[[File:Williamson ether synthesis of dipropyl ether.png|none|thumb|576x576px|An example for a Williamson ether synthesis to make dipropyl ether. X<sup>−</sup> product is not shown.]]