Which of the following statements most accurately defines the rigid stereochemical prerequisite for — Reaction Mechanism Chemistry Question

💡 Solution & Explanation

The $E2$ mechanism is a concerted, single-step reaction. For the new $\pi$ -bond to form concurrently as the $C-H$ and $C-X$ bonds break, the breaking orbitals must be aligned parallel to each other. An anti-coplanar geometry (a dihedral angle of $180^\circ$) is required to minimize steric repulsion in the transition state and provide optimal orbital overlap.