1130-49-0 2-Oxo-3(delta)-4,5,5-trimethylcyclopentenylacetic acid 2-Oxo-delta(3)-4,5,5-trimethylcyclopentenylacetic acid 3-Cyclopentene-1-acetic acid, 2,2,3-trimethyl-5-oxo- Otmcpa