Formation of dioxirane from carbonyl oxide

Abstract

1 H₂C=O^⊕-O^⊖ → O-^O 2The isomerization (a) should be exothermic and should have an activation barrier of 23 kcal mol^-1. This follows from the results of ab initio calculations, which, moreover, suggest an initiating pyramidalization at the central O atom, which is facilitated by Π-donor substituents like fluorine: In cis- and trans-HFCO₂ the activation energy is still only 17 and 8 kcal mol^-1, respectively. However, fluorodixirane is kinetically less stable than 2. Only geminal methyl groups effect both a thermodynamic and a kinetic stabilization.