[1-[2',5'-bis-O-(tert-butyldimethylsilyl)-β-D-ribofuranosyl]-4-N-[Nα-(benzyloxycarbonyl)-valyl-propyl]cytosine]-3'-spiro-5''-[4''-amino-1'',2''-oxathiole-2'',2''-dioxide]

4-N-[Nα-(benzyloxycarbonyl)valylprolyl]-1-β-D-arabinofuranosylcytosine

乙基缬氨酸酯