Oxirene is a hypothesized

heterocyclic A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different elements as members of its ring(s). Heterocyclic chemistry is the branch of organic chemistry dealing with the synthesis, properties, and ...

chemical compound which contains an unsaturated three-membered ring containing two carbon atoms and one oxygen atom. Because it has never been observed, the substance is mainly studied by quantum chemical computational techniques. As the configuration is extremely strained and proposed to be an anti-aromatic 4 π electron system, oxirene is expected to be very high energy and unstable according to these calculations. Moreover, different computational methods draw different conclusions as to whether the structure constitutes a true

molecule A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and bioch ...

(i.e., a local minimum on the potential energy surface) or merely a

transition state In chemistry, the transition state of a chemical reaction is a particular configuration along the reaction coordinate. It is defined as the state corresponding to the highest potential energy along this reaction coordinate. It is often marked wi ...

between two isomeric molecular species. Experimental indications exist that substituted oxirenes (as intermediates or transition states) may be involved in carbonylcarbene rearrangements observed in the

Wolff rearrangement The Wolff rearrangement is a reaction in organic chemistry in which an α-diazocarbonyl compound is converted into a ketene by loss of dinitrogen with accompanying 1,2-rearrangement. The Wolff rearrangement yields a ketene as an intermediate produ ...

. Computational evidence also point to the intermediacy of oxirenes in the ozonolysis of alkynes.

References

{{Reflist Oxygen heterocycles Ethers Hypothetical chemical compounds Three-membered rings Antiaromatic compounds