Explanation:

* Steric Hindrance: Isoborneol has a more sterically hindered structure due to the presence of the hydroxyl group (OH) on the bridgehead carbon atom. This steric strain makes it less stable than borneol.

* Hydrogen Bonding: Borneol can form stronger hydrogen bonds with itself and other molecules because the hydroxyl group is in a more accessible position. This intermolecular interaction contributes to its higher thermodynamic stability.

* Experimental Evidence: Experimental studies have shown that borneol is the major product in the reduction of camphor, indicating that it is the more stable isomer.

Therefore, borneol is the thermodynamically more stable isomer of borneol and isoborneol.