MHT CET202616 April 2026Evening ShiftChemistryAlcohols Phenols and EthersActual
Identify the product X in the following reaction.
Options
- A2,3-dimethyl-2-butene
- B3,2-diethyl butene
- C3,3-dimethyl-1-butene
- D2,2-diethyl butene
Correct answer
A. 2,3-dimethyl-2-butene
Step-by-step solution
The given reaction is the acid-catalyzed dehydration of an alcohol. The reactant is 3,3-dimethyl-2-butanol. Protonation of the hydroxyl group by H₂SO₄ to form a good leaving group ( -OH₂^+ ). CH₃-C(CH₃)₂-CH(OH)-CH₃ + H^+ CH₃-C(CH₃)₂-CH(OH₂^+)-CH₃ Loss of a water molecule to form a secondary ( 2^ ) carbocation. CH₃-C(CH₃)₂-CH(OH₂^+)-CH₃ CH₃-C(CH₃)₂-CH^+-CH₃ + H₂O The 2^ carbocation undergoes a 1,2-methyl shift to form a more stable tertiary ( 3^ ) carbocation. CH₃-C(CH₃)₂-CH^+-CH₃ 1,2-methyl shift CH₃-C^+(CH₃)-CH(CH