Acetic acid (2R,3R,4R,5R)-4-acetoxy-5-acetoxymethyl-2-(2-acetylamino-6-oxo-1,6-dihydro-purin-9-yl)-tetrahydro-furan-3-yl ester
2',3',5'.-tri-O-acetyl-8-bromoguanosine
2-acetamido-6-ethoxy-8-methylthio-9-(2-O-tosyl-1-β-D-ribofuranosyl)-9H-purine
Acetic acid (2R,3R,4R,5R)-4-acetoxy-5-acetoxymethyl-2-(2-acetylamino-6-ethoxy-8-methylsulfanyl-purin-9-yl)-tetrahydro-furan-3-yl ester
2-acetamido-6-ethoxy-9-(2',3',5'-tri-O-acetyl-β-D-ribosyl)purine