CO[C@H]1OC(=O)C[C@H]1[C@@H]1CC=C2[C@@]1(C)CC[C@@H]1[C@@]3(C)C=CC(=O)C(C)(C)[C@@H]3CC(O)[C@@]21C (4S,5S)-4-[(5R,8R,9R,10R,13S,17S)-7-hydroxy-4,4,8,10,13-pentamethyl-3-oxo-5,6,7,9,11,12,16,17-octahydrocyclopenta[a]phenanthren-17-yl]-5-methoxyoxolan-2-one