Question

Consider the reaction of chlorocyclohexane with ethoxide in a suitable inert solvent. The major product according to my textbook is cyclohexene, which implies E2 reaction pathway. Why not SN2?

EtO⁻ is an unstable anion, so why can it act as nucleophile rather than acting as a base?

Answer 1

The reaction of chlorocyclohexane with ethoxide in a suitable solvent results in the formation of cyclohexene through an E2 (elimination) reaction pathway. Ethoxide can act as a nucleophile in this reaction despite being an unstable anion.

Step-by-step explanation:

In the reaction of chlorocyclohexane with ethoxide in a suitable inert solvent, the major product formed is cyclohexene. This implies the pathway of the reaction is E2 (elimination) rather than SN2 (substitution).

The reason for this is that although ethoxide (EtO⁻) is an unstable anion, it can still act as a nucleophile in this reaction because the E2 mechanism involves the abstraction of a hydrogen atom by the base to form an alkene, rather than the direct substitution of the leaving group by the nucleophile.