2-N-(benzyloxycarbonyl)-3',5'-bis-O-(tert-butyldimethylsilyl)-2'-deoxyguanosine

O6-Allyl-3',5'-O-bis(tert-butyldimethylsilyl)-2'-deoxyguanosine

5'-O-(4,4'-dimethoxytrityl)-2-N-cyclohexylcarbamoyldeoxyguanosine 3'-(2-cyanoethyl N,N-diisopropylphosphoramidite)

5'-O-(4,4'-dimethoxytrityl)-2-N-(N-cyclohexyl-N-methylcarbamoyl)deoxyguanosine 3'-(2-cyanoethyl-N,N-diisopropylphosphoramidite)