(2’R,5S,7R,8R,10R,13S,14S)-methyl 5-cyano-10,13-dimethyl-3,5′-dioxo-1,2,3,4,4′,5,5′,6,7,8,10,12,13,14,15,16-hexadecahydro-3’H-spiro[cyclopenta[a]phenanthrene-17,2′-furan]-7-carboxylate