In which of these cyclic compounds you find the minimum angle strain?

Options

A. `C_3H_6`
B. `C_4H_8`
C. `C_5H_10`
D. `C_6H_12`

Answer

To determine which cyclic compound has the minimum angle strain among cyclopropane, cyclobutane, cyclopentane, and cyclohexane, we can analyze the bond angles in each compound and how they compare to the ideal tetrahedral angle of 109.5 degrees.

### Step-by-Step Solution:

1. **Understanding Angle Strain**:
- Angle strain occurs when the bond angles in a molecule deviate from the ideal tetrahedral angle of 109.5 degrees found in sp³ hybridized carbon atoms.

2. **Analyzing Cyclopropane**:
- Cyclopropane has bond angles of approximately 60 degrees.
- This is significantly less than the ideal tetrahedral angle, resulting in high angle strain.

3. **Analyzing Cyclobutane**:
- Cyclobutane has bond angles of approximately 90 degrees.
- While this is an improvement over cyclopropane, it is still less than 109.5 degrees, leading to moderate angle strain.

4. **Analyzing Cyclopentane**:
- Cyclopentane has bond angles of approximately 108 degrees.
- This is very close to the ideal tetrahedral angle, indicating low angle strain.

5. **Analyzing Cyclohexane**:
- Cyclohexane has bond angles of about 120 degrees in its planar form; however, it predominantly exists in non-planar conformations (chair and boat forms).
- In these conformations, the bond angles can approximate the ideal tetrahedral angle (109.5 degrees), resulting in zero angle strain.

6. **Conclusion**:
- Among the cyclic compounds analyzed, cyclohexane has the least angle strain because it can adopt conformations that minimize strain.
- Therefore, the compound with the minimum angle strain is **cyclohexane**.

### Final Answer:
- **Cyclohexane** has the minimum angle strain.