What is "oxirene"

n. (context organic compound English) The unsaturated three-membered heterocycle having two carbon atoms, one oxygen atom and one double bond

Oxirene is a hypothesized heterocyclic chemical compound which contains an unsaturated three-membered ring containing two carbon atoms and one oxygen atom. As the configuration is extremely strained, no consensus exists whether the structure constitutes a molecule or whether it is merely a transition state. The substance is therefore mainly evaluated by molecular modeling techniques.

Experimental indications exist that oxirene (as intermediate or transition state) occurs in the Wolff rearrangement.