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Question #44412
The Question
An organic compound \textbf{X}, 1,1-bis(4-nitrophenyl)-2-methylpropane-1,2-diol, is heated with concentrated . Assuming standard Pinacol-Pinacolone rearrangement conditions, identify the major product formed.
Options
- A.
1,2-bis(4-nitrophenyl)-2-methylpropan-1-one
- B.
3,3-bis(4-nitrophenyl)butan-2-one
- C.
1,1-bis(4-nitrophenyl)-2-methylprop-2-en-1-ol
- D.
2,2-dimethyl-3,3-bis(4-nitrophenyl)oxirane
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|Inductive Effect Trends
Why This Question Is Tricky
Common Mistakes
Students often blindly apply the heuristic that 'diaryl carbocations are more stable than dialkyl carbocations' (Aryl > Alkyl), assuming C1 forms the most stable carbocation.
They fail to calculate how the strong EWG () destabilizes the transition state and the intermediate at C1.
Consequently, they predict the wrong migration (methyl shift) leading to the distractor.
The true pathway proceeds via the kinetically and thermodynamically favored tertiary dialkyl carbocation at C2, forcing the migration of the 4-nitrophenyl group despite its poor migratory aptitude.
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 |