(2S,3S,4S,5S)-2-((S)-1-(benzyloxycarbonylamino)-2-hydroxyethyl)-5-(5-methyl-2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)tetrahydrofuran-3,4-diyl diethanoate   、                                                                                      
乙酸酐                                                                                                                                                              在
                                                                                                                                                                                 
吡啶   、                                                                                                  
4-二甲氨基吡啶                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
二氯甲烷                                                                                  为溶剂,
                                                                                                                                                    反应 1.0h,
                                                                                                                以183 mg的产率得到(2S,3S,4S,5S)-2-((S)-1-(benzyloxycarbonylamino)-2-(ethanoyloxy)ethyl)-5-(5-methyl-2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)tetrahydrofuran-3,4-diyl diethanoate