With a suitable example write equations for the Williamson's ether synthesis

Explanation

Willamson.s synthesis : It is an important method for the preparation of symmertical and unsymmetrical ethers. In this method, an alkyl halide is allowed to react with sodium alkoxide.
`R-X+R. underset(..)overset(..) (O) Na^(+) to R - underset(..)overset(..) (O) - R . + NaX`
Ethers containing subsitituted alkyl groups `(2^(@) or 3^(@) )` may also e prepared by this method. The reaction involves `S_(N) 2` attack of an alkoxide ion on primary alkyl halide.
`CH_3 -underset(underset(CH_3)|)overset(overset(CH3)|) C - underset(..)overset(..) (O) Na^(+) + CH_3 - Br to CH_3 - underset(..)overset(..) (O) - underset(underset(CH_3)|)overset(overset(CH3)|)C - CH_(3) + NaBr`
In case of secondary and tertiary alkyl halides, elimination competes over substitution. if a tertiary alkyl halide is used, an alkene is the only reaction product and no ether is formed.
`underset("2-Methyl propene")(CH_3 -underset(underset(CH_3)|)overset(overset(CH3)|) C - Br+ Na^(+) underset(..) overset(..) (O) - CH_(3) to CH_(3) - underset(underset(CH_3)|)C = CH_(2) + NaBr + CH_(3) OH)`