(3aR,6aR)-5-ethenylspiro[3a,6a-dihydrofuro[2,3-d][1,3]dioxole-2,1'-cyclohexane]   、                                                                                      
2,5-二羟基苯乙酮                                                                                                                                                              在
                                                                                                                                                                                 
silver(l) oxide                                                                                                                                  作用下,
                                                                                                                                                                                                                            以78%的产率得到(4a'S,7a'R,10a'R,10b'R,10c'R)-4a'-acetyl-4a',5',7a',10a',10b',10c'-hexahydrospiro[cyclohexane-1,9'-naphtho[1',2':4,5]furo[2,3-d][1,3]dioxole]-1',4'-dione