Methylation of N′-benzyloxy-1-(2-deoxy-β-D-ribofuranosyl)-5-formamidoimidazole-4- carboxamidine (2a) followed by hydrogenolysis of the N′-benzyloxy-group and cyclization produced the hitherto unknown 3-methyl-2′-deoxyadenosine (5a), which was readily hydrolysed to 3-methyladenine (6) in H2) O at pH⩽ 7· 0 and to (6) and the imidazole-(2- deoxy) riboside (4a) at pH 8· 98.
