2-(2-Amino-naphthalen-1-ylamino)-9-[(2R,4S,5R)-4-(tert-butyl-dimethyl-silanyloxy)-5-(tert-butyl-dimethyl-silanyloxymethyl)-tetrahydro-furan-2-yl]-1,9-dihydro-purin-6-one

O6-benzyl-3',5'-bis-O-(tert-butyldimethylsilyl)-2'-deoxyxanthosine

N2-(2-nitronaphth-1-yl)-O6-benzyl-3',5'-bis-O-(tert-butyldimethylsilyl)-2'-deoxyguanosine

3',5'-bis-O-(tert-butyldimethylsilyl)-O2-(4-methylbenzenesulfonyl)-2'-deoxyxanthosine