[1-[2',5'-bis-O-(tert-butyldimethylsilyl)-β-D-ribofuranosyl]-3-N-[3-N'-[lysyl-prolylamino]propyl]thymine]-3'-spiro-5''-[4''-amino-1'',2''-oxathiole-2'',2''-dioxide]

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