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

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