(1R,4S,4aR,9bS)-6-acetyl-7,9-dimethoxy-1-(1-methylethyl)-1,2,3,4,4a,9b-hexahydrodibenzofuran-4-spiro-4'-dioxolan-2'-one                                                                                                                                                              在
                                                                                                                                                                                 
三溴化硼                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
二氯甲烷                                                                                  为溶剂,
                                                                                                                                                    反应 1.0h,
                                                                                                                以99%的产率得到(1R,4S,4aR,9bS)-6-acetyl-7-hydroxy-9-methoxy-1-(1-methylethyl)-1,2,3,4,4a,9b-hexahydrodibenzofuran-4-spiro-4'-dioxolan-2'-one