重氮甲烷   、                                                                                      
((2S,4aR,4bR,6aR,8S,10aR,10bR,12aS)-8-Acetoxy-4a,4b,7,7,10a-pentamethyl-1-oxo-octadecahydro-chrysen-2-yl)-acetic acid                                                                                                                                                                                              以
                                                                                         
乙醚                                                                                  为溶剂,
                                                                                                                                                                                        生成                                                 methyl 2-[(2S,4aR,4bR,6aR,8S,10aR,10bR,12aS)-8-acetyloxy-4a,4b,7,7,10a-pentamethyl-1-oxo-3,4,5,6,6a,8,9,10,10b,11,12,12a-dodecahydro-2H-chrysen-2-yl]acetate