Synthesis of 2′-deoxytubercidin {4-amino-7-(2-deoxy-β-D-erythro-pentofuranosyl)pyrrolo[2,3-d]pyrimidine} from the parent antibiotic

Abstract

Desulphurisation of 4-amino-7-(2-S-benzyl-2-thio-2-deoxy-β-D-arabinofuranosyl)pyrrolo[2,3-d]pyrimidine (7), obtained by intramolecular episulphonium ion rearrangement of the isomeric 3′-S-benzyl-thio-xylo-2′-O-methylsulphonyl derivatives (5)[obtained in three steps from 2′,3′-anhydrotubericidin (1)] using sodium benzoate in NN-dimethylformamide, gave the elusive 2′-deoxy-tubercidin (8).