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Question #44434
The Question
An optically active cyclic diol, (1R,2R,4R,5S)-4,5-dimethylcyclohexane-1,2-diol, is subjected to oxidative cleavage using an excess of periodic acid () in aqueous methanol at 298 K. Which of the following correctly describes the stereochemistry and optical activity of the major organic product?
Options
- A.
Optically inactive \textit{meso}-(3R,4S)-3,4-dimethylhexanedial
- B.
Optically active (3R,4R)-3,4-dimethylhexanedial
- C.
Optically active (3S,4S)-3,4-dimethylhexanedial
- D.
Racemic mixture of (3R,4R) and (3S,4S)-3,4-dimethylhexanedial
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
Glycol Periodic Acid Cleavage|Optical Activity and Enantiomers
Why This Question Is Tricky
Common Mistakes
This problem tests the 'conservation of optical activity' fallacy.
Students often incorrectly assume that reactions of chiral molecules that do not directly break bonds at the stereocenters will always yield chiral products.
Here, the oxidative cleavage destroys the asymmetry of the ring, revealing a hidden plane of symmetry in the open-chain product and converting a chiral glycol into an achiral meso dicarbonyl.
Quick Facts About This Question
Question Information
| Subject | Chemistry |
| Chapter | Alcohols, Phenols, and Ethers - Class 12 |
| Concept | Glycol Periodic Acid Cleavage |
| Difficulty | 8 |
| Cognitive Load | 7 |
| Target Solve Time | 160 sec |
| Access | Free |