Sodium salt of 2'-deoxy-N6-dimethylaminomethylene-3'-O-(tetrahydro-2H-pyran-2-yl)adenosine (VIII) reacted with dibenzyl p-toluenesulfonyloxymethanephosphonate (Ia) to give dibenzyl ester of 2'-deoxy-N6-dimethylaminomethylene-5'-O-phosphonomethyl-3'-O-(tetrahydro-2H-pyran-2-yl)adenosine (XI) which after deprotection afforded the final 2'-deoxy-5'-O-phosphonomethyladenosine (XII). 2'-Deoxy-5'-O-hydroxymethanephosphonyladenosine (XIV) and 5'-O-benzyloxymethanephosphonyl-2'-deoxyadenosine (XIII) were isolated as a side product. The preparation of 2'-deoxy-5'-O-phosphonomethylguanosine (XVI) and protection of the starting nucleoside were analogous to those of compound XII. In the 2'-deoxy-3'-O-phosphonomethylnucleosides series, 2'-deoxy-3'-O-phosphonomethylcytidine (XXI) and 2'-deoxy-3'-O-phosphonomethyladenosine (XXVII) were prepared, using N4-benzoyl-5'-O-tert-butyldiphenylsilyl-2'-deoxycytidine (XVIII) and 5'-O-tert-butyldiphenylsilyl-2'-deoxy-N6-dimethylaminomethyleneadenosine (XXIV), respectively, as starting compounds.
2'-脱氧核苷酸(XII)的制备方法如下:先将2'-脱氧-N6-二甲氨基甲基烯基-3'-O-(四氢-2H-吡喃-2-基)腺苷(VIII)的钠盐与二苄基对甲苯磺酰氧甲基膦酸酯(Ia)反应,得到2'-脱氧-N6-二甲氨基甲基烯基-5'-O-膦酸甲酯-3'-O-(四氢-2H-吡喃-2-基)腺苷的二苄基酯(XI),去保护后得到最终产物2'-脱氧-5'-O-膦酸甲基腺苷(XII)。2'-脱氧-5'-O-羟甲基膦酸酯腺苷(XIV)和5'-O-苄氧甲基膦酸酯-2'-脱氧腺苷(XIII)为副产物。2'-脱氧-5'-O-膦酸甲基鸟苷(XVI)的制备和起始核苷的保护与化合物XII类似。在2'-脱氧-3'-O-膦酸甲基核苷系列中,使用N4-苯甲酰-5'-O-叔丁基二苯基硅基-2'-脱氧胞苷(XXI)和5'-O-叔丁基二苯基硅基-2'-脱氧-N6-二甲氨基甲基烯基腺苷(XXIV)作为起始化合物,制备了2'-脱氧-3'-O-膦酸甲基胞苷(XXI)和2'-脱氧-3'-O-膦酸甲基腺苷(XXVII)。