5'-O-(4,4'-dimethoxytrityl)-2'-O-[(1-N-methyltetrazol-5-yl)ethyl]-6-N-phenoxyacetyladenosine   、                                                                                      
双(二异丙基氨基)(2-氰基乙氧基)膦                                                                                                                                                              在
                                                                                                                                                                                 
二异丙基铵盐四氮唑                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
二氯甲烷                                                                                  为溶剂,
                                                                                                                                                                                        以55%的产率得到5'-O-(4,4'-dimethoxytrityl)-2'-O-[(1-N-methyltetrazol-5-yl)ethyl]-6-N-phenoxyacetyladenosine 3'-(2-cyanoethyl N,N-diisopropylphosphoramidite