(5'R)-3',5'-di-O-(tert-butyldimethylsilyl)-5'-(tert-butylcarbonyl)thymidine

3'-O-TBDMS-5'-aldehydic thymidine

3'-O-acetylthymidine 5'-O-(1-imidazolyl)carbamate

3'-O-(1,3-benzodithiol-2-yl)thymidine

5'-O-TBDPS-dT