If a tertiary alkyl halide is used, an alkene is the only reaction product and no ether is formed. For example, the reaction of CH3ONa with (CH3)3C−Br gives exclusively 2-methylpropene. CH3−
CH3
|
C
|
CH3
−Br + N
+
a
−
O
- CH3 →
CH3−
C
|
CH3
=CH2
2−Methylpropene
+ NaBr + CH3OH It is because alkoxides are not only nucleophiles but strong bases as well. They react with alkyl halides leading to elimination reactions.