Question

Whichof following cannot undergo an E2 reaction?

• A. A
• B. B
• C. C
• D. None (all can undergo an $E_2$ reaction)

Answer 1

The correct option is A A

E2 is a bimolecular reaction. It is a single step reaction goes through a single transition state. It is a concerted reaction. In E2 reaction, two groups/atoms depart simultaneously from adjacent carbons with a proton being abstracted by a base.
In the compound (A), $\beta -$ carbon doesn't have a proton group to undergo elimination. Thus, compound (A) does not undergo E2 elimination.
Compound (B) and (C) has $\beta -$ carbon so they will undergo E2 elimination reaction.