Spiro(cyclopenta(7,8)phenanthro(4b,5-b)oxirene-7(3H),2'(3'H)-furan)-10-carboxylic acid, 2,4,4',4a,5',5a,6,6a,8,9,9a,9b,10,11-tetradecahydro-4a,6a-dimethyl-2,5'-dioxo-, methyl ester, (4aS,4bR,5aR,6aS,7 R,9aS,9bR,10R)-