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Question #44410
The Question
Compound \textbf{P}, 2-methyl-1,1-diphenylpropane-1,2-diol, is treated with a catalytic amount of anhydrous -toluenesulfonic acid (TsOH) in excess ethanol at 298 K. What is the major organic product formed?
Options
- A.
3,3-diphenylbutan-2-one
- B.
1-ethoxy-2-methyl-1,1-diphenylpropan-2-ol
- C.
2-methyl-1,2-diphenylpropan-1-one
- D.
2,2-diethoxy-3,3-diphenylbutane
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Mechanism_Trap
Don't get tricked by the process! Learn the mechanical traps used in competitive exam questions.
Concepts Behind This Question
Pinacol-Pinacolone Rearrangement|Nucleophilic Addition Sterics
Why This Question Is Tricky
Common Mistakes
This question tests the competition between intramolecular rearrangement and intermolecular nucleophilic addition, alongside regioselectivity traps.
Students often fall into three traps: 1) Relying solely on migratory aptitude (Ph > Me) without evaluating the stability of the initial carbocation, leading to the wrong rearranged product (Option C). 2) Assuming the stable carbocation will be captured by the external nucleophile (ethanol) present in excess, ignoring the kinetic advantage of intramolecular rearrangement and steric hindrance (Option B). 3) Assuming the final ketone will react with excess alcohol to form a ketal, failing to recognize the severe steric hindrance preventing nucleophilic addition at the carbonyl carbon (Option D).
Quick Facts About This Question
Question Information
| Subject | Chemistry |
| Chapter | Alcohols, Phenols, and Ethers - Class 12 |
| Concept | Pinacol-Pinacolone Rearrangement |
| Difficulty | 8 |
| Cognitive Load | 7 |
| Target Solve Time | 160 sec |
| Access | Free |