Williamson synthesis
It is an important laboratory method for the preparation of
symmetrical and unsymmetrical ethers In this method, an alkyl
halide is allowed to react with sodium alkoxide R–X +
R –ONa
’
R–O–R + Na X
’
+
–
Ethers containing  substituted alkyl groups (secondary or tertiary)
may also be prepared by this method The reaction involves SN2 attack
of an alkoxide ion on primary alkyl halide