What is "cyclobutanetetrone"

n. (context organic compound English) A cyclic oxocarbon derived from cyclobutane

Cyclobutanetetrone, also called tetraoxocyclobutane, is an organic compound with formula CO or (-(C=O)-), the fourfold ketone of cyclobutane. It would be an oxide of carbon, indeed a tetramer of carbon monoxide.

The compound seems to be thermodynamically unstable. As of 2000, it had yet to be synthesized in significant amounts but may have transient existence as detected by mass spectrometry.