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Question #43964
The Question
An organic compound , 4-hydroxy-5,5-dimethylhexan-2-one (), is treated with amalgamated zinc and concentrated hydrochloric acid under heating. Assuming the reaction is thermodynamically controlled with respect to the carbon skeleton, identify the major organic product formed.
Options
- A.
2,3-dimethylhex-2-ene
- B.
2,2-dimethylhex-3-ene
- C.
2,2-dimethylhexane
- D.
2,3-dimethylhexane
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Exception_Exposure
Learn to identify edge cases and boundary exceptions that JEE examiners hide in math problems.
Concepts Behind This Question
Clemmensen vs. Wolff-Kishner|SN1 Carbocation Rearrangement
Why This Question Is Tricky
Common Mistakes
This question tests the competition between functional group reduction and acid-catalyzed carbocation rearrangement.
Students often blindly apply the Clemmensen reduction to the carbonyl group, either ignoring the hydroxyl group or dehydrating it without considering the carbon skeleton.
The 'hidden variable' is the kinetic rapidity of the Wagner-Meerwein rearrangement (1,2-methyl shift) in the highly sterically hindered neopentyl-like secondary carbocation, which outpaces the heterogeneous surface reduction of the ketone.
This leads to a rearranged, unsaturated hydrocarbon rather than a simple straight-chain alkane.
Quick Facts About This Question
Question Information
| Subject | Chemistry |
| Chapter | Aldehydes, Ketones, and Carboxylic Acids - Class 12 |
| Concept | Clemmensen vs. Wolff-Kishner |
| Difficulty | 8 |
| Cognitive Load | 7 |
| Target Solve Time | 160 sec |
| Access | Free |