[1S,4aR,6R,10R,13aS,(-)]-1,2,3,4,4a,5,6,9,10,11,12,13a-Dodecahydro-1,6-dihydroxy-4,4,13a-trimethyl-9-methylene-10,7-metheno-7H-benzocycloundecene-8,13-dione