The molecule is a monocarboxylic acid anion that is the conjugate base of (5R)-carbapenem-3-carboxylic acid, obtained by deprotonation of the carboxy group. It is a conjugate base of a 1-carbapenem-3-carboxylic acid.
(5R)-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate