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Question #44636
The Question
Methyl 2-hydroxybenzoate is treated with exactly two equivalents of methylmagnesium bromide () in dry diethyl ether at 273 K. After the reaction reaches completion, the mixture is subjected to careful aqueous acidic workup (). Identify the major organic product formed.
Options
- A.
1-(2-Hydroxyphenyl)ethan-1-one
- B.
2-(2-Hydroxyphenyl)propan-2-ol
- C.
Equimolar mixture of methyl 2-hydroxybenzoate and 2-(2-hydroxyphenyl)propan-2-ol
- D.
1-(2-Methoxyphenyl)ethan-1-one
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
Grignard Reagent Sensitivity|Nucleophilic Acyl Substitution|Esterification Reversibility
Why This Question Is Tricky
Common Mistakes
This problem tests the kinetic dominance of acid-base reactions over nucleophilic addition and the stabilization of tetrahedral intermediates via chelation.
Students typically memorize that esters react with Grignard reagents to form tertiary alcohols because the intermediate ketone is more reactive.
If they account for the acidic proton but miss the chelation, they will assume the intermediate collapses, leading to a mixture of unreacted ester and tertiary alcohol (Option C).
However, the ortho-phenoxide creates a stable magnesium chelate (conceptually similar to a Weinreb amide), preventing collapse until acidic workup, thus stopping the reaction cleanly at the ketone stage.
Quick Facts About This Question
Question Information
| Subject | Chemistry |
| Chapter | Haloalkanes and Haloarenes - Class 12 |
| Concept | Grignard Reagent Sensitivity |
| Difficulty | 8 |
| Cognitive Load | 7 |
| Target Solve Time | 160 sec |
| Access | Free |