Summary
A new method of synthesis of 6-alkylpurine ribosides and 8-alkyladenosines from purine nucleosides is described. Reaction of 2′,3′,5′-tri- O -benzoyl-β- D -ribofuranosyl-6-methylsulfonylpurine with a carbanion from ethyl aceto-acetate gave the 6-ethoxycarbonylmethyl derivative. Alkylation followed by decarboxylation of the debenzoylated 6-ethoxycarbonylmethylpurine riboside afforded 6-ethyl to 6-pentyl-purine ribosides in high yields. Similar treatment of the 8-methylsulfonyladenosine derivative afforded 8-ethyladenosine and related 8-substituted adenosines.