(2’R,5S,7R,8S,10R,11R,13S,14S)-methyl 5-cyano-10,13-dimethyl-11-((methylsulfonyl)oxy)-3,5′-dioxooctadecahydro-3’H-spiro[cyclopenta[a]phenanthrene-17,2′-furan]-7-carboxylate