Across the four warheads, torsional transition states occur at dihedral angles of Θ ‡ ≈ 134 • (between To understand the observed stability trend between the enolate rotamers, the electronic structures of the individual rotamers were further investigated. First, the Mulliken charge distributions within each rotamer were extracted (see Figures S3-S6 in the Supporting Information). As the augcc-pVTZ basis set is fairly complete, there is some ambiguity within our Mulliken analyses as it is not a priori clear which electrons should count towards the basis functions of one atom over another. However, we only use Mulliken analysis as a qualitative indicator of trends across the various systems. For each rotamer, we observe that every hydrogen atom has a positive Mulliken charge, whereas the oxygen atom and every carbon atom have negative Mulliken charges (apart from the former-carbonyl carbon atom). The oppositely-charged nature of these species could give rise to some favorable non-covalent electrostatic interactions, if permitted conformationally.