5'-O-(tert-butyldimethylsilyl)-5-methyl-2',3'-O-thionocarbonyluridine

5'-O-(tert-butyldimethylsilyl)-2',3'-bis-O-[[(β-cyanoethyl)thio]thiocarbonyl]-5-methyluridine

3'-β-(phenylselenyl)-5'-O-trityl-3'-deoxythymidine

5'-O-三苯甲基-3'-O-甲磺酰基胸苷