(3S,3aR,5aR,7Z,11E,14aR,14bR)-1,2,3,3a,4,5,5a,6,9,10,13,14,14a,14b-Tetradecahydro-5a,12,14b-trimethyl-3-(1-methylvinyl)cycloundec[e]indene-8-carboxylic acid