乙酸酐   、                                                                                      
(5S,8R,9S,10R,13S,14S)-3-Ethoxy-16-[1-hydroxy-meth-(Z)-ylidene]-10,13-dimethyl-1,2,5,6,7,8,9,10,11,12,13,14,15,16-tetradecahydro-cyclopenta[a]phenanthren-17-one                                                                                                                                                              在
                                                                                                                                                                                 
吡啶                                                                                                                                  作用下,
                                                                                                                                                                                        反应 24.0h,
                                                                                                                以96%的产率得到Acetic acid (5S,8R,9S,10S,13S,14S,17R)-16,16-bis-acetoxymethyl-10,13-dimethyl-3-oxo-hexadecahydro-cyclopenta[a]phenanthren-17-yl ester