Question

Which of the following options is correct about the following reaction?

• A. Reaction is goes through $E_2$ Mechanism.
• B. Reaction goes though anti elimination so it is highly stereo specific.
• C. Reaction is bimolecular with respect to RDS step.
• D. Over all order of the reaction is 2.

Answer 1

The correct option is D Over all order of the reaction is 2.

The first step of the reaction is abstraction of proton by base, thus generating a carbanion intermediate.

The intermediate carbanion is stabilized by two factors : (1) resonance and (2) inductive effect produced by $Cl$. So the reaction will proceed through E1cB mechanism.
The progress of reaction is as follow :


Since strong base is used and the carbanion formed is highly stable so first step will be fast. Molecuarity w.r.t. RDS step is 1. Overall order of the reaction is 2.
It is neither stereo specific nor stereo selective.