Chemistry - Halogen Derivative Question with Solution | TestHub
Matrix match
List - I (Reactants) | List - II (Statements w.r.t major products) |
|---|---|
(P) | (1) E1CB mechanism forms major product |
(Q)
| (2) Major product is formed by E2 reaction |
(R)
| (3) Reaction proceeds with transition state |
(S) | (4) Carbanion is involved as intermediate |
Options:
Answer:
Solution:
(P) (2, 3): Bromocyclopentane undergoes a standard, single-step concerted E2 elimination via a transition state to form cyclopentene.
(Q) (3): The reaction between sodium -butoxide and methyl iodide is an Sɴ2 substitution (Williamson ether synthesis) that proceeds via a single transition state without any intermediate.
(R) (1, 4): The presence of the electron-withdrawing carbonyl group makes the -hydrogen highly acidic, favoring an E1cB mechanism that involves a stable carbanion intermediate.
(S) (2, 3): Hofmann elimination of the quaternary ammonium salt proceeds via a concerted E2 mechanism involving a transition state to yield the less-substituted alkene as the major product.
