乙酸酐   、                                                                                      
methyl 1α,2α,3β,23-tetrahydroxyolean-12-en-28-oate                                                                                                                                                              在
                                                                                                                                                                                 
吡啶                                                                                                                                  作用下,
                                                                                                                                                                                                                            以21.5 mg的产率得到(4aS,6aS,6bR,8aR,9R,10R,11R,12R,12aR,12bS,14bS)-10,11-Diacetoxy-9-acetoxymethyl-12-hydroxy-2,2,6a,6b,9,12a-hexamethyl-1,3,4,5,6,6a,6b,7,8,8a,9,10,11,12,12a,12b,13,14b-octadecahydro-2H-picene-4a-carboxylic acid methyl ester