1'-O-methyl-2'-deoxy-3'-O-tert-butyldiphenylsilyl-5'-O
6-(5-bromo-5-methyl-6-hydro-1H-pyrimidine-2,4-dione) riboside                                                                                                                                                              在
                                                                                                                                                                                 4 A molecular sieve   、                                                                                                  
三氟化硼乙醚                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
二氯甲烷                                                                                  为溶剂,
                                                                                                                                                    反应 1.5h,
                                                                                                                以49%的产率得到(5S,6S)-5-bromo-O
6-5'-cyclo-6-hydro-2'-deoxy-3'-O-tert-butyldiphenylsilylthymidine