5'-O-(4,4'-dimethoxytrityl)-3'-deoxythymidine-3'-sulfamoyl-[3'(N)->5'(O)]-3'-O-(tert-butyldimethylsilyl)thymidine

3'-deoxy-5'-O-(4,4'-dimethoxytrityl)-3'-{{6-{[(9H)-(fluoren-9-ylmethoxy)carbonyl]-amino}-1-thioxohexyl}amino}thymidine

3'-deoxy-3'-{{6-{[(9H-fluoren-9-ylmethoxy)carbonyl]amino}-1-thiohexyl}amino}thymidine

3'-deoxythymidin-3'-ylsulfamoyl-[3'(N)->5'(O)]-thymidine

3'-deoxy-5'-O-(4,4'-dimethoxytrityl)-3'-[(2-methyl-1-thioxopropyl)amino]thymidine