2H-Phenanthro(1,2-c)pyran-2-carboxylic acid, 1,4,4a,4b,5,7,8,9,10,10a,10b,11,12,12a-tetradecahydro-6,10b-dihydroxy-2,4b,7,7,10a,12a-hexamethyl-12-methylene-1,4,5,8-tetraoxo-, methyl ester, (2R,4aR,4bS,10aS,10bS,12aR)- 71911-90-5