1H-3,9a-Methanocyclopent(c)oxocin-4-carboxylic acid, octahydro-4-hydroxy-7-(1-methylethylidene)-, (3R,4R,6aS,9aS)- 1H-3,9a-Methanocyclopent(c)oxocin-4-carboxylic acid, octahydro-4-hydroxy-7-(1-methylethylidene)-, (3R-(3alpha,4alpha,6aalpha,9aalpha))- 67309-95-9 Aspterric acid