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Question #44397
The Question
Compound \textbf{X} (3-hydroxybenzoic acid) is subjected to two parallel reaction pathways:
Pathway I: \textbf{X} is treated with and aqueous at , followed by careful acidification to yield the major product \textbf{P}.
Pathway II: \textbf{X} is treated with (1 eq.) and excess anhydrous at , followed by acidic workup to yield the major product \textbf{Q}.
Based on the principles of electrophilic aromatic substitution and functional group reactivity, identify \textbf{P} and \textbf{Q}.
Options
- A.
\textbf{P} = 4-formyl-3-hydroxybenzoic acid; \textbf{Q} = 3-acetoxybenzoic acid
- B.
\textbf{P} = 5-formyl-3-hydroxybenzoic acid; \textbf{Q} = 5-acetyl-3-hydroxybenzoic acid
- C.
\textbf{P} = 2-formyl-3-hydroxybenzoic acid; \textbf{Q} = 4-acetyl-3-hydroxybenzoic acid
- D.
\textbf{P} = 4-formyl-3-hydroxybenzoic acid; \textbf{Q} = 5-acetyl-3-hydroxybenzoic acid
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
Reimer-Tiemann Reaction|Friedel-Crafts on Carboxylic Acids|Electrophilic Substitution Control
Why This Question Is Tricky
Common Mistakes
The problem tests the 'functional group priority' and 'Lewis acid coordination' traps in electrophilic aromatic substitution.
Students often assume the -COOH group will dictate the regiochemistry (meta-direction) or completely prevent the Reimer-Tiemann reaction.
However, the strongly activating phenoxide ion overrides the -COOH group, directing the carbene to the less hindered ortho position (C4).
Conversely, in Friedel-Crafts acylation, students frequently forget that AlCl3 coordinates with both -OH and -COOH groups, transforming them into strongly deactivating groups that halt ring acylation, leading exclusively to O-acylation.
Quick Facts About This Question
Question Information
| Subject | Chemistry |
| Chapter | Alcohols, Phenols, and Ethers - Class 12 |
| Concept | Reimer-Tiemann Reaction |
| Difficulty | 8 |
| Cognitive Load | 7 |
| Target Solve Time | 160 sec |
| Access | Free |