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Question #44622
The Question
Consider the solvolysis of (2S, 3S)-2-chloro-3-(methylthio)butane in an aqueous medium at 298 K. The reaction proceeds exclusively via a cyclic intermediate due to Neighboring Group Participation (NGP). Identify the major stereoisomeric product(s) formed.
Options
- A.
Only (2S, 3S)-3-(methylthio)butan-2-ol
- B.
Only (2R, 3S)-3-(methylthio)butan-2-ol
- C.
Equimolar mixture of (2S, 3S) and (2R, 3S) isomers
- D.
Racemic mixture of (2R, 3S) and (2S, 3R) isomers
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
Steric Hindrance in SN2|SN2 Stereochemical Inversion|Optical Activity and Enantiomers
Why This Question Is Tricky
Common Mistakes
This question tests the stereochemical consequences of Neighboring Group Participation (NGP).
A common trap is assuming standard intermolecular SN2, which would predict 100% inversion to the (2R, 3S) product.
Another trap is memorizing that NGP leads to a racemic mixture without considering the substrate's diastereomer.
The threo (2S, 3S) isomer forms a chiral trans-episulfonium intermediate with C2 symmetry, leading to 100% retention.
In contrast, the erythro isomer would form a meso cis-episulfonium intermediate, yielding a racemic mixture.
Quick Facts About This Question
Question Information
| Subject | Chemistry |
| Chapter | Haloalkanes and Haloarenes - Class 12 |
| Concept | Steric Hindrance in SN2 |
| Difficulty | 8 |
| Cognitive Load | 7 |
| Target Solve Time | 160 sec |
| Access | Free |