9-<3',5'-bis-O-(tert-butyldimethylsilyl)-2'-deoxy-β-D-erythro-pentofuranosyl>-6-(phenylthio)-2-<bis<(phenylthio)carbonyl>amino>purine

9-<3',5'-bis-O-(tert-butyldimethylsilyl)-2'-deoxy-β-D-erythro-pentofuranosyl>-6-(phenylthio)-2-ureidopurine

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

3',5'-bis-O-(tert-butyldimethylsilyl)-2'-deoxy-6-O-methyl-2-N-(methoxycarbonyl)guanosine

2-amino-9-<3',5'-bis-O-(tert-butyldimethylsilyl)-2'-deoxy-β-D-erythro-pentofuranosyl>purine

2,6-diamino-9-<3',5'-bis-O-(tert-butyldimethylsilyl)-2'-deoxy-β-D-erythro-pentofuranosyl>purine

6-methoxy-9-<3',5'-bis-O-(tert-butyldimethylsilyl)-2'-deoxy-β-D-erythro-pentafuranosyl>-2-ureidopurine

2-amino-6-<(benzyloxycarbonyl)amino>-9-<3',5'-bis-O-(tert-butyldimethylsilyl)-2'-deoxy-β-D-erythro-pentofuranosyl>purine

2-<(methoxycarbonyl)amino>-9-<3',5'-bis-O-(tert-butyldimethylsilyl)-2'-deoxy-β-D-erythro-pentofuranosyl>-6-phenylthiopurine

{6-Benzyloxy-9-[(2R,4S,5R)-4-(tert-butyl-dimethyl-silanyloxy)-5-(tert-butyl-dimethyl-silanyloxymethyl)-tetrahydro-furan-2-yl]-9H-purin-2-yl}-carbamic acid benzyl ester

{6-Benzyloxy-9-[(2R,4S,5R)-5-(tert-butyl-dimethyl-silanyloxymethyl)-4-hydroxy-tetrahydro-furan-2-yl]-9H-purin-2-yl}-carbamic acid benzyl ester

{6-Benzyloxy-9-[(2R,4S,5R)-4-(tert-butyl-dimethyl-silanyloxy)-5-hydroxymethyl-tetrahydro-furan-2-yl]-9H-purin-2-yl}-carbamic acid benzyl ester