The most stable conformation of 3-fluorobutan-2-ol is

The most stable conformation of 3-fluorobutan-2-ol is the one where the –OH group at C-2 and the fluorine atom at C-3 are gauche to each other.

Explanation:

1.  

2. Structure:

   • Butan-2-ol has the –OH group attached to C-2.

   • In 3-fluorobutan-2-ol, a fluorine atom is attached to C-3.

3. Conformational analysis:

   • Around the C-2–C-3 bond, there can be anti or gauche conformations between –OH and –F.

   • Normally, anti would be favored to minimize steric repulsion.

4.  

5. Gauche effect:

   • In molecules with electronegative substituents on adjacent carbons, a gauche conformation is stabilized.

   • Here, stabilization arises from hyperconjugation and orbital interactions:

     • The lone pair on oxygen overlaps with the σ* orbital of C–F bond, giving extra stabilization.

6.  

7. Conclusion:

   • Due to this gauche effect, the most stable conformation of 3-fluorobutan-2-ol is the one where –OH and –F are gauche to each other (dihedral angle ≈ 60°).

   •  

Final Answer:
The most stable conformation of 3-fluorobutan-2-ol is the gauche conformation, where the hydroxyl group at C-2 and the fluorine atom at C-3 are gauche to each other.