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Question #44391
The Question
Consider the organic compound \textbf{P}, 3-\textit{tert}-butyl-5-methoxyphenol. \textbf{P} undergoes the following reaction sequence:\ 1. \ce{NaOH} (aq), followed by evaporation to dryness.\ 2. \ce{CO2} (g) at and pressure.\ 3. Dilute \ce{H3O+}, yielding major product \textbf{X}.\ 4. \textbf{X} is treated with \ce{(CH3CO)2O} in the presence of catalytic \ce{H2SO4} to yield major product \textbf{Y}.\ Identify the IUPAC name of product \textbf{Y}.
Options
- A.
2-Acetoxy-5-\textit{tert}-butyl-3-methoxybenzoic acid
- B.
2-Acetoxy-3-\textit{tert}-butyl-5-methoxybenzoic acid
- C.
4-Acetoxy-2-\textit{tert}-butyl-6-methoxybenzoic acid
- D.
4-Acetoxy-6-\textit{tert}-butyl-2-methoxybenzoic acid
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
Kolbe-Schmitt Reaction Mechanism|EAS in Phenols|Ortho-Effect in Anilines
Why This Question Is Tricky
Common Mistakes
This question tests the 'Ortho-Effect' and transition state stabilization in the Kolbe-Schmitt reaction.
Students often assume that an ortho-position flanked by two groups is too sterically hindered for electrophilic attack.
However, the hidden variable is the coordinative ability of the adjacent group.
While a bulky, non-coordinating group (like tert-butyl) blocks its adjacent position, a coordinatively active group (like methoxy) actively stabilizes the transition state via multidentate chelation with the sodium ion and the electrophile (CO2).
This thermodynamic stabilization overrides standard steric hindrance, dictating the regioselectivity.
Quick Facts About This Question
Question Information
| Subject | Chemistry |
| Chapter | Alcohols, Phenols, and Ethers - Class 12 |
| Concept | Kolbe-Schmitt Reaction Mechanism |
| Difficulty | 8 |
| Cognitive Load | 7 |
| Target Solve Time | 160 sec |
| Access | Free |