(1'S,3'R,4'R,5'R,7'R)-N2-isobutyryl-7-{4'-acetoxy-1'-phenyl-3'-(tert-butyldiphenylsilyloxymethyl)-2',6'-dioxabicyclo[3.3.0]oct-7'-yl}guanine

(1'S,3'R,4'R,5'R,7'S)-N2-isobutyryl-7-{4'-acetoxy-1'-phenyl-3'-(tert-butyldiphenylsilyloxymethyl)-2',6'-dioxabicyclo[3.3.0]oct-7'-yl}guanine

5'-O-(4,4'-dimethoxytrityl)-1'-deoxy-1'-phenyl-β-D-ribofuranose

5'-O-(4,4'-dimethoxytrityl)-2'-O-tert-butyldimethylsilyl-1'-deoxy-1'-phenyl-β-D-ribofuranose

N-(4-{(2S,3R,4S,5R)-5-[Bis-(4-methoxy-phenyl)-phenyl-methoxymethyl]-3,4-dihydroxy-tetrahydro-furan-2-yl}-phenyl)-2,2,2-trifluoro-acetamide