An anomalous effect of fluorine on the conformational equilibrium of 2-fluorocyclohexane-1,3-dione

Abstract

Conformational stabilities of 2-halocyclohexane-1,3-diones are strongly affected by steric and dipolar effects involving the carbonyl groups and the equatorial halogen. However, 2-fluorocyclohexane-1,3-dione has been found to be mostly equatorial, because of electron delocalization in this conformer that overcomes repulsive interactions, while the other halogen derivatives perform as expected.