[(E,6R)-6-[(8S,9R,10R,13R,14S,16R,17R)-2-ethoxy-16-hydroxy-4,4,9,13,14-pentamethyl-3,11-dioxo-8,10,12,15,16,17-hexahydro-7H-cyclopenta[a]phenanthren-17-yl]-6-hydroxy-2-methyl-5-oxohept-3-en-2-yl] acetate