An Electron Diffraction Investigation of Methyl Formate, Methyl Acetate and Methyl Chloroformate

The structures of simple carboxylic esters have received considerable elucidation from studies of dipole moments. This work is summarized and discussed in the fourth and fifth chapters of Wheland's book, "The Theory of Resonance." 'The conclusion from these studies is that simple aliphatic esters do not have free rotation about the carbonyl carbon-ether oxygen bond, but are planar with the configuration I, which we shall call cis.