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Question #44469
The Question
The monoterpene (+)-limonene (\ce{1-methyl-4-(prop-1-en-2-yl)cyclohex-1-ene}) is subjected to reductive ozonolysis (\ce{O3} followed by \ce{Zn/H2O}) to yield an acyclic tricarbonyl compound \textbf{X}. Compound \textbf{X} is then treated with a catalytic amount of \ce{KOH} in ethanol and heated under reflux for 24 hours to yield \textbf{Y} as the major product. Identify the IUPAC name of \textbf{Y}.
Options
- A.
(2-methyl-4-oxocyclohex-2-en-1-yl)acetaldehyde
- B.
1,1'-(cyclopent-1-ene-1,4-diyl)di(ethan-1-one)
- C.
5-(3-oxobutyl)cyclopent-2-en-1-one
- D.
(4-methyl-2-oxocyclohex-3-en-1-yl)acetaldehyde
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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
Ozonolysis Fragmentation Patterns|Enolate Regioselectivity|Aldol Condensation Directionality
Why This Question Is Tricky
Common Mistakes
This problem tests the student's mastery of regioselectivity in complex intramolecular aldol condensations under thermodynamic versus kinetic control.
The 'trap' lies in the presence of a highly reactive aldehyde, which tempts students to predict a 5-membered ring (kinetic product).
The 'hidden variable' is the reversibility of the reaction under prolonged heating, which favors the 6-membered cyclohexenone.
Furthermore, it requires differentiating between two possible thermodynamic 6-membered rings based on the steric hindrance of the bulky substituent relative to the carbonyl group.
Quick Facts About This Question
Question Information
| Subject | Chemistry |
| Chapter | Hydrocarbons - Class 11 Part 2 |
| Concept | Ozonolysis Fragmentation Patterns |
| Difficulty | 8 |
| Cognitive Load | 7 |
| Target Solve Time | 160 sec |
| Access | Free |