9-(5'-O-t-Butyldimethylsilyl-2',3'-O-isopropylidene-b-D-ribofuranosyl)-6-chloro-7-deazaguanine

2-Amino-4-chloro-7-(2,3-O-isopropylidene-5-O-tert-butyldimethylsily--D-ribofuranosyl)pyrrolo[2,3,-d]pyrimidine

4-Chloro-7-[5-O-[(1,1-dimethylethyl)dimethylsilyl]-2,3-O-(1-methylethylidene)--D-ribofuranosyl]-7H-pyrrolo[2,3-d]pyrimidin-2-amine