3',5'-bis-O-[(tert-butyl)dimethylsilyl]-2'-deoxy-N2-isobutyryl-O6-[(2,4,6-triisopropylphenyl)sulfonyl]guanosine

Acetic acid (2R,3S,5R)-2-acetoxymethyl-5-(2-isobutyrylamino-6-oxo-1,6-dihydro-purin-9-yl)-tetrahydro-furan-3-yl ester