(10R,13S,17R)-10,13-Dimethyl-1,2,7,8,9,10,11,12,13,14,15,16-dodecahydro-5'H-spiro[cyclopenta[a]phenanthrene-17,2'-oxolane]-3,5',6-trione 生成 (5R,9R,13R)-5,13-dimethylpentacyclo[10.8.0.02,9.05,9.013,18]icosa-2,17-diene-8,16,19-trione 、 (5S,9S,12S)-16-hydroxy-5,12-dimethylpentacyclo[10.8.0.02,9.05,9.013,18]icosa-13(18),14,16-triene-8,19-dione