15,20-epoxy-2α,3β-dihydroxy-13,14:14,15-diseco-18-nor-pregna-5,15(16),17(20)-trien-13-one-14-oic acid                                                                                                                                                              在
                                                                                                                                                                                 
吡啶   、                                                                                                  
4-二甲氨基吡啶                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
乙醚                                                                                  为溶剂,
                                                                                                                                                    反应 25.0h,
                                                                                                                生成                                                 (1S,2R,6R,7R,8aR)-6,7-Bis-(4-bromo-benzoyloxy)-8a-methyl-1-[3-(2-methyl-furan-3-yl)-3-oxo-propyl]-1,2,3,5,6,7,8,8a-octahydro-naphthalene-2-carboxylic acid methyl ester