(8R,9S,10S,13S,14S)-2-Bromo-17-hydroxy-10,13-dimethyl-8,9,10,11,12,13,14,15,16,17-decahydro-cyclopenta[a]phenanthren-3-one   、                                                                                      
丙二酸二乙酯                                                                                                                                                              在
                                                                                                                                                                                 
1,1,2,3-四甲基胍                                                                                                                                  作用下,
                                                                                                                                                                                        反应 6.0h,
                                                                                                                以28%的产率得到(1S,2S,8R,9S,10S,13S,14S)-17-Hydroxy-10,13-dimethyl-3-oxo-2,3,8,9,10,11,12,13,14,15,16,17-dodecahydro-1H-cyclopropa[1,2]cyclopenta[a]phenanthrene-20,20-dicarboxylic acid diethyl ester