Acetolactone

In organic chemistry, αlactone refers to a functional group, the smallest possible lactone. It is a family of unstable, three-membered heterocycles, containing an epoxide ring fused with a carbonyl group.

Acetolactone
Names
IUPAC name
Oxiran-2-one
Preferred IUPAC name
Oxiranone
Identifiers
3D model (JSmol)
ChemSpider
  • InChI=1S/C2H2O2/c3-2-1-4-2/h1H2 Y
    Key: HZSIFDFXFAXICF-UHFFFAOYSA-N Y
  • InChI=1/C2H2O2/c3-2-1-4-2/h1H2
    Key: HZSIFDFXFAXICF-UHFFFAOYAQ
  • O=C1OC1
Properties
C2H2O2
Molar mass 58.036 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y verify (what is YN ?)
Infobox references

The parent, acetolactone (α-acetolactone), is an organic compound with formula C
2
H
2
O
2
, and has not been isolated in bulk. The compound was first described in 1997 as a transient species in mass spectrometry experiments.

Generally, α‑lactones are produced by the cryogenic, photochemical decarboxylation of peroxymalonic anhydrides. Even at 77 K, the products rapidly polymerize or decarbonylate to ketones or aldehydes.

An exception is bis(trifluoromethyl)acetolactone ((CF
3
)
2
C
2
O
2
), stabilized by its two trifluoromethyl groups. That compound has a half-life of 8 hours at 25 °C.

Α-Thiolactones can be produced via oxygen transfer from a nitrone to a thioketene.