Abstract
2, 6-Diacetamido-8-hydroxy-9-(3, 5-O-diacetyl-2-O-tosyl-β-D-ribofuranosyl)purine (III) was cyclized with ammonia in methanol to give a mixture of 2, 6-diamino-8, 2'-anhydro-8-hydroxy-9-β-D-arabinofuranosylpurine (V) and 2-acetamido-6-amino-8, 2'-anhydro-8-hydroxy-9-β-D-arabinofuranosylpurine (IV), which was deacetylated to the cyclonucleoside (V) with 40% methylamine.After acetylation, the cyclonucleoside (V) was converted to 2, 6-diamino-9-β-D-arabinofuranosylpurine (IX) by cleavage of the anhydro linkage with H2S in pyridine followed by Raney Ni dethiolation. Alternatively, acetylated arabinofuranosylguanine (X) derived from 8, 2'-anhydro-8-hydroxy-9-β-D-arabinofuranosylguanine was chlorinated with phosphoryl chloride and aminated with ammonia in metthanol to afford the arabinoside (IX).
