2'-Deoxy-3'-O-[(2-methyl-2-propanyl)(diphenyl)silyl]-3,4-dihydrot hymidine

5'-O-三苯甲基-3'-O-甲磺酰基胸苷

3'-O-(叔丁基二甲基硅烷基)胸苷

3'-Tosyl-5'-O-trityl thymidine