QTAIM explanation of the anomeric effect in the O–C–O unit II: 2-Methoxyoxane and 2,2-dimethoxypropane

QTAIM relative atomic populations and delocalization indices of the conformers of 2-methoxyoxane and 2,2-dimethoxypropane dissent from the view of the hyperconjugative model. In contrast, their evolutions are explained successfully on the basis of electron–electron repulsions. The anomeric stabilization in these compounds is mainly due to the flow of electron density from the central hydrogens to carbons and oxygens. This electron transference is related to the number of H–C–O-lp gauche arrangements and, therefore, to the repulsions between lone pairs and central hydrogens.