The molecule is a 5-oxo monocarboxylic acid anion that is the conjugate base of 1-deoxy-11-oxopentalenic acid, obtained by deprotonation of the carboxy group; major species at pH 7.3. It is a conjugate base of a 1-deoxy-11-oxopentalenic acid.
(1R,2S,5R,8S)-2,10,10-trimethyl-3-oxotricyclo[6.3.0.01,5]undec-6-ene-6-carboxylate