C/C1=C/[C@@]2(C)C(=CCC[C@@H]2C)CC[C@H](O)[C@H]1O (4S,4aS,5Z,7S,8S)-4,4a,6-trimethyl-3,4,7,8,9,10-hexahydro-2H-benzo[8]annulene-7,8-diol