For cyclohexane, which of the following factors does not make the boat conformation less stable than the chair conformation

Options

A. 1,3-diaxial interactions
B. flag pole interactions
C. angle strain
D. torsional strain

Answer

To determine which factor does not make the boat conformation of cyclohexane less stable than the chair conformation, we need to analyze the different types of interactions and strains that affect the stability of these conformations.

### Step-by-Step Solution:

1. **Understanding Cyclohexane Conformations**:
- Cyclohexane can adopt different conformations, primarily the chair and boat forms. The chair conformation is generally more stable than the boat conformation.

2. **Identifying Stability Factors**:
- The stability of these conformations is influenced by various factors, including steric interactions, torsional strain, and angle strain.

3. **Analyzing the Chair Conformation**:
- In the chair conformation, there are interactions known as 1,3-diaxial interactions. These occur between axial substituents on the first and third carbon atoms, leading to steric hindrance and a decrease in stability.

4. **Analyzing the Boat Conformation**:
- The boat conformation has its own set of interactions, such as flagpole interactions, which occur between the two axial hydrogens at the ends of the boat. These interactions also contribute to the instability of the boat conformation.

5. **Considering Other Strains**:
- Angle strain occurs when bond angles deviate from the ideal tetrahedral angle (109.5°), which is not a significant factor in the stability comparison between chair and boat forms of cyclohexane.
- Torsional strain arises from eclipsing interactions between bonds, which is more pronounced in the boat conformation than in the chair conformation.

6. **Identifying the Correct Answer**:
- The question asks for the factor that does **not** make the boat conformation less stable than the chair conformation. Among the options, angle strain is not a significant factor affecting the stability of the boat conformation compared to the chair conformation.

### Conclusion:
The factor that does not make the boat conformation less stable than the chair conformation is **angle strain**.