First Completely Stable Axial Conformers of Monosubstituted Cyclohexanes at Room Temperature

摘要

In summary, an empirical shift rule of the chemical shifts of the α-protons of oxygen-containing homologues was found, which provides evidence for the anisotropy of the C-H single bond. According to the anomalous downfield shift of the H_20 signals and their coupling constants, stable and conformationally pure axial monosubstituted cyclohexanes are obtained for the first time in the chiral alkyl nitronic ester and o-alkyloxime, which is rationally explained by steric effects.