乙酸酐   、                                                                                      20(S),24(R)-epoxydammarane-3α,11α,25-triol                                                                                                                                                              在
                                                                                                                                                                                 
吡啶                                                                                                                                  作用下,
                                                                                                                                                                                                                            以29 mg的产率得到Acetic acid (3R,5R,8R,9R,10S,11R,14R,17S)-3-hydroxy-17-[(2S,5R)-5-(1-hydroxy-1-methyl-ethyl)-2-methyl-tetrahydro-furan-2-yl]-4,4,8,10,14-pentamethyl-hexadecahydro-cyclopenta[a]phenanthren-11-yl ester