LCAO-MO-SCF STUDIES OF CARBON-CARBON BOND CLEAVAGE IN ETHYLENE OXIDE

Nonempirical LCAO-MO-SCF studies of carbon-carbon bond cleavage in ethylene oxide indicate the presence of two open forms. In one form (the 90, 90 form) the terminal methylene groups are perpendicular to the C-O-C plane. In the other (the 0, 0 form), the terminal methylene groups are in the C-O-C plane. On the basis of molecular correlation diagrams such as those of Hoffmann and Woodward, one would expect that either of these open forms could add stereospecifically to olefins. Previously Huisgen had sug-gested that the 0, 0 open form was an intermediate in the 1,2 cycloaddition of tetracyanoethylene oxide to olefins; however, a 90, 90 form is also consistent with the experimental data.