Question

Boat from of cyclohexane is less stable than chair form because:

• A. it floats on water
• B. of interaction of flag pole hydrogens on top of carbon
• C. eclipsed $C-H$ bonds
• D. of high dipole moment

Answer 1

Answer: (B), (C)

eclipsed $C-H$ bonds

Boat conformer is not as stable as chair because some of C-H bonds are eclipsed, thus they have high torsional strain. Also they are destabilized by the close proximity of flagpole hydrogens.
Due to an interaction of flag pole H, it creates a steric strain at top of carbon and make it higher energetic.

Thus, option (b) and (c) are correct.