Which of the following has maximum angle strain ?

Options

A.
B.
C.
D.

Answer

To determine which of the given cyclic compounds has the maximum angle strain, we need to analyze the bond angles in each compound and compare them to the ideal tetrahedral angle of 109.28 degrees, which is characteristic of sp³ hybridized carbon atoms.

### Step-by-Step Solution:

1. **Identify the Compounds**: The compounds in question are cyclopropane, cyclobutane, cyclopentane, and cyclohexane.

2. **Determine the Ideal Bond Angle**: For sp³ hybridized carbon atoms, the ideal bond angle is 109.28 degrees.

3. **Analyze the Bond Angles**:
- **Cyclopropane**: The bond angles are approximately 60 degrees.
- **Cyclobutane**: The bond angles are approximately 90 degrees.
- **Cyclopentane**: The bond angles are approximately 108 degrees.
- **Cyclohexane**: The bond angles are approximately 120 degrees (in its chair conformation).

4. **Calculate Angle Strain**:
- **Cyclopropane**: The angle strain is significant because the actual angle (60 degrees) is much less than the ideal angle (109.28 degrees).
- **Cyclobutane**: The angle strain is present but less than cyclopropane since 90 degrees is closer to 109.28 degrees.
- **Cyclopentane**: The angle strain is minimal as 108 degrees is very close to 109.28 degrees.
- **Cyclohexane**: The angle strain is negligible as it can adopt conformations (like chair) that allow it to have bond angles close to the ideal angle.

5. **Conclusion**: Among all these compounds, cyclopropane has the smallest bond angle (60 degrees), which results in the highest angle strain compared to the ideal tetrahedral angle of 109.28 degrees.

### Final Answer:
**Cyclopropane has the maximum angle strain.**

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