[(2S,3R,5R)-5-(5-Methyl-2,4-dioxo-3,4-dihydro-2H-pyrimidin-1-yl)-2-(toluene-4-sulfonyloxymethyl)-tetrahydro-furan-3-yl]-acetic acid methyl ester

5'-O-(tert-butyldiphenylsilyl)-3'-C-methylenecarboxylic-3'-deoxythymidine