(Rac)-1-ethyl-7-methoxy-4a-methyl-4,4a,9,10-tetrahydro-3h-phenanthren-2-one   、                                                                                      
三溴化硼                                                                                                                                                              在
                                                                                                                                                                                 crude product                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
二氯甲烷                                                                                  为溶剂,
                                                                                                                                                    反应 5.0h,
                                                                                                                以v, stepwise gradient) as eluent to yield E64的产率得到(Rac)-1-ethyl-7-hydroxy-4a-methyl-4,4a,9,10-tetrahydro-3h-phenanthren-2-one