2,5-二羟基苯甲醛   、                                                                                      
ethyl (E)-3-[(3aR,6aR)-spiro[3a,6a-dihydrofuro[2,3-d][1,3]dioxole-2,1'-cyclohexane]-5-yl]prop-2-enoate                                                                                                                                                              在
                                                                                                                                                                                 
silver(l) oxide                                                                                                                                  作用下,
                                                                                                                                                                                        反应 72.0h,
                                                                                                                以100%的产率得到ethyl (4a'R,5'S,7a'R,10a'R,10b'R,10c'R)-4a'-formyl-1',4'-dioxo-1',4',4a',5',7a',10a',10b',10c'-octahydrospiro[cyclohexane-1,9'-naphtho[1',2':4,5]furo[2,3-d][1,3]dioxole]-5'-carboxylate