(2aE,4E,5'S,6S,6'R,7S,8E,11R,13S,15S,17aR,20R,20aR,20bS)-20,20b-dihydroxy-5',6,8,19-tetramethyl-6'-[(1S)-1-methylpropyl]-17-oxo-5',6,6',10,11,14,15,17,17a,20,20a,20b-dodecahydro-2H,7H-spiro[11,15-methanofuro[4,3,2-pq][2,6]benzodioxacyclooctadecine...