1-[2-deoxy-5-O-(4,4'-dimethoxytriphenylmethyl)-β-D-erythro-pentofuranosyl]-1,5-dihydro-6-[(2-methylpropanoyl)amino]-3-(3-trifluoroacetamidoprop-yl)-4H-pyrazolo[3,4-d]-pyrimidin-4-one   、                                                                                      
双(二异丙基氨基)(2-氰基乙氧基)膦                                                                                                                                                              在
                                                                                                                                                                                 diisopropylethylamine tetrazolium                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
二氯甲烷                                                                                  为溶剂,
                                                                                                                                                    反应 2.0h,
                                                                                                                以82.3%的产率得到1-[2-deoxy-5-O-(4,4'-dimethoxytriphenylmethyl)-β-D-erythro-pentofuranosyl]-1,5-dihydro-6-[(2-methylpropanoyl)amino]-3-(3-trifluoroacetamidoprop-yl)-4H-pyrazolo[3,4-d]-pyrimidin-4-one 3-(2-cyanoethyl-diisopropylphosphoramidite)