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.

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.