(8S,11R,13S,14S,17S)-17-hydroxy-11-[4-((RS)-1-hydroxyethyl)phenyl]-13-methyl-17-pentafluoroethyl-1,2,6,7,8,11,12,13,14,15,16,17-dodecahydrocyclopenta[a]phenanthren-3-one   、                                                                                      
溴乙酸叔丁酯                                                                                                                                                              在
                                                                                                                                                                                 
四丁基硫酸氢铵   、                                                                                                  potassium hydroxide                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
二氯甲烷                                                                                  为溶剂,
                                                                                                                                                    反应 2.0h,
                                                                                                                以21%的产率得到{(1RS)-1-[4-((8S,11R,13S,14S,17S)-17-hydroxy-13-methyl-3-oxo-17-pentafluoroethyl-2,3,6,7,8,11,12,13,14,15,16,17-dodecahydro-1H-cyclopenta[a]phenanthren-11-yl)-phenyl]ethoxy}acetic acid tert-butyl ester