2-(acetylamino)-7-{3,5-bis-O-[(tert-butyl)dimethylsilyl]-2-deoxy-α-D-erythro-pentofuranosyl}-1,7-dihydro-6H-purin-6-one

6-Allyloxy-9-[(2R,4S,5R)-4-(tert-butyl-dimethyl-silanyloxy)-5-(tert-butyl-dimethyl-silanyloxymethyl)-tetrahydro-furan-2-yl]-3,9-dihydro-purin-2-one