(4R,6R)-4-ethyl-6-((S)-1-((1aR,3aR,3bS,5aS,6R,8aS,8bS,10R,10aR)-10-methoxy-3a,5a-dimethylhexadecahydrocyclopenta[a]cyclopropa[2,3]cyclopenta[1,2-f]naphthalen-6-yl)ethyl)tetrahydro-2H-pyran-2-one