3-Methylideneoxolane-2,5-dione

Abstract

The title compound (itaconic anhydride), C5H4O3, consists of a five-membered carbon-oxygen ring in a flat envelope conformation (the unsubstituted C atom being the flap) with three exocyclic double bonds to two O atoms and one C atom. In contrast to the bond lengths, which are very similar to those in itaconic acid in its pure form or in adducts with other molecules, the bond angles differ significantly because of the effect of ring closure giving rise to strong distortions at the C atoms involved in the exocyclic double bonds. In the crystal, C - H⋯O interactions link the molecules, forming an extended three-dimensional network. © 2013 Beginn et al.