(1R,4aR)-7-Isopropyl-1,4a-dimethyl-5,6-dioxo-1,2,3,4,4a,5,6,9,10,10a-decahydro-phenanthrene-1-carboxylic acid 在
silica gel 作用下,
以
四氯化碳 为溶剂,
以58%的产率得到(3aS,10bS)-10-Hydroxy-8-isopropyl-3a,10b-dimethyl-1,3,3a,5a,10b,10c-hexahydro-2H-5-oxa-acephenanthrylene-4,9-dione