<1R-(1α,4aβ,4bα,7β,10aα)>-1,2,3,4,4a,4b,5,6,7,8,10,10a-Dodecahydro-7-(3-methoxycarbonylpropanoyl)-1,4a,7-trimethyl-8-oxo-1-phenanthrencarbonsaeure-methylester                                                                                                                                                              在
                                                                                                                                                                                 
potassium tert-butylate                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
苯                                                                                  为溶剂,
                                                                                                                                                                                        以65%的产率得到<4R-(4α,5α,9α,10β,13α)>-2,3,4,5,6,9,10,11,12,13,16,17-Dodecahydro-4,10,13-trimethyl-17-oxo-1H-cyclopenta
phenanthren-4,15-dicarbonsaeure-dimethylester