Question

$2$-Phenylethylbromide when heated with $NaOEt$, elimination takes place. No deuterium exchange takes place when the reaction is carried out in $C_2H_5OD$ solvent. The mechanism will be

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

Answer 1

Answer: (B)

$E2$ elimination

Answer 2

It is a primary bromide. So it will undergo elimination either by $E2$ or $E1cB$. Since there is no deuterium exchange in $C _{2} H _{5} OD$ solvent, $C-H$ bond is not broken to form carbanion. Hence the actual mechanism is $E2$ only.