Chemistry - ALCOHOL & ETHER Question with Solution | TestHub
List - I | List - II |
|---|---|
(A) | (P) Major product is Saytzeff alkene |
(B)
| (Q) Major product is Hoffmann alkene |
(C)
| (R) Rearragement takes place |
(D) | (S) Markovnikov's addition takes place |
| (T) Carbocation (classical or non-classical) is formed as an intermediate |
Options:
Answer:
Solution:
(A) P, R, T: Dehydration of butan-1-ol forms a primary carbocation intermediate (T), which rearranges via a 1,2-hydride shift (R) to a more stable secondary carbocation, yielding but-2-ene as the Saytzeff alkene major product (P).
(B) R, S, T: Electrophilic addition of HBr to allylbenzene forms a carbocation intermediate (T), which undergoes a 1,2-hydride shift rearrangement (R) to the highly stable benzylic position, following overall Markovnikov's addition (S).
(C) Q, T: Acid-catalyzed dehydration of the substituted cyclobutanol forms a carbocation intermediate (T) that undergoes ring rearrangement to relieve strain, ultimately eliminating to give the less-substituted Hoffmann alkene (Q) as the major product.
(D) S, T: Kucherov's hydration of phenylacetylene via Hg²⁺/dil. H₂SO₄ proceeds through a non-classical mercurinium ion/carbocation-like intermediate (T) following Markovnikov's addition (S) to yield acetophenone via keto-enol tautomerism.
