Question

2-phenylethylbromide when heated with $NaOEt$, elimination takes place. No deuterium exchange takes place when the reaction is carried out in $C_2{H}_{5}OD$ solvent. The mechanism will be:

• A. $E1$ elimination
• B. $E2$ elimination
• C. $E1cB$ elimination
• D. $E2$ or $E1cB$

Answer 1

The correct option is B $E2$ elimination

It is a primary bromide. So it will undergo elimination either by $E2$ or $E1cB$. Since there isnodeuterium exchange in $C_2{H}_{5}OD$ solvent, $C-H$ bond is not broken to form carbanion.

Hence, the actual mechanism is $E2$ only.