Find the most stable form

Options

A.
B.
C.
D. Both B & C

Answer

To determine the most stable conformation from the given options, we will analyze each conformation step by step.

### Step 1: Identify the conformations
We have three conformations to analyze:
1. **Anti-planar (Staggered Conformation)**
2. **Gauche Conformation**
3. **Eclipsed Conformation**

### Step 2: Analyze the Anti-planar (Staggered Conformation)
In the first conformation (staggered), the two groups are positioned opposite to each other (180 degrees apart). This arrangement minimizes the electron-electron repulsion between the groups, making it relatively stable.

**Hint:** Look for the arrangement of groups that minimizes repulsion.

### Step 3: Analyze the Gauche Conformation
In the second conformation (gauche), the angle between the two groups is 60 degrees. Although this conformation has some steric hindrance, it can also involve favorable interactions such as hydrogen bonding. In this case, if there is an OH group and a fluorine atom, hydrogen bonding can occur, which stabilizes this conformation.

**Hint:** Check for any interactions like hydrogen bonding that can enhance stability.

### Step 4: Analyze the Eclipsed Conformation
In the third conformation (eclipsed), the two groups are aligned (0 degrees apart). This arrangement leads to significant electron-electron repulsion, making this conformation the least stable of the three.

**Hint:** Remember that eclipsed conformations generally have higher energy due to repulsion.

### Step 5: Compare Stability
- **Staggered Conformation:** Most stable due to minimized repulsion.
- **Gauche Conformation:** More stable than staggered if hydrogen bonding is present.
- **Eclipsed Conformation:** Least stable due to maximum repulsion.

### Conclusion
Considering the presence of hydrogen bonding in the gauche conformation, it becomes more stable than the staggered conformation. Therefore, the most stable conformation among the given options is the **Gauche Conformation** (Option 2).

**Final Answer:** The most stable form is the Gauche Conformation (Option 2).