rel-(2R,3aR,6aS,8aS,12aS,12bR,13bS)-3a-hydroxy-2-methoxy-6a,9,9,12a-tetramethyl-2,3,3a,6a,7,8,8a,9,10,11,12,12a,12b,13b-tetradecahydro-4H-benzo[a]furo[3,2-j]xanthen-4-one