1,4-Methano-1H-indene-1-acetic acid, octahydro-.alpha.,3a,5-trimethyl-6,8-dioxo-, [1R-[1.alpha.,1(S*),3a.beta.,4.alpha.,5.alpha.,7a.beta.]]- 1,4-Methanoindan-1-acetic acid, hexahydro-.alpha.,3a,5-trimethyl-6,8-dioxo- 510-35-0 NSC138622 Santonic acid