‡ and ∆G Θ↓ ‡ , between two enolate intermediates with dihedral angles 0 • ≤ Θ 1 < Θ 2 < 360 • were calculated as the difference between the Gibbs free energy of the torsional transition state and the Gibbs free energy of the enolate with Θ = Θ 1 and Θ = Θ 2 , respectively. Enolate intermediates were obtained after reoptimization of energetic minima, without any geometry constraints, and their nature was confirmed by virtue of possessing all real frequencies.