2β-(2',6'-dimethoxy-4'-methylbenzoyl)-3β-methoxycarbonyl-7-oxabicyclo<2.2.1>heptane                                                                                                                                                              在
                                                                                                                                                                                 phenyltrimethylammonium tribromide                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
四氢呋喃                                                                                  为溶剂,
                                                                                                                                                    反应 5.0h,
                                                                                                                以1.9 g的产率得到2α-bromo-2β-(2',6'-dimethoxy-4'-methylbenzoyl)-3β-methoxycarbonyl-7-oxabicyclo(2.2.1)heptane