Synthesis of ara-3,7-dideazaadenosine and related pyrrolo[3,2-c]pyridine D-arabinofuranosides

Abstract

Pyrrolo[3,2-c] pyridine (3,7-dideazapurine)D-arabinonucleosides, including ara-3,7-dideazaadenosine 1, ara-3,7-dideazainosine 2, and ara-3,7-dideazanebularine 3 were synthesized from 1-(β-D-arabinofuranosyl)-4,6-dichloro-1H-pyrrolo[3,2-c] pyridine 10. Compound 10 was obtained by glycosylation of the 4,6-dichloro-1H-pyrrolo[3,2-c]pyridine 5 anion (phase-transfer conditions) with the 2,3,5-tri-O-benzyl-D-arabinofuranosyl halides 6 or 7. The ratio of glycosylation products (β:α) was 4:1 in the case of the bromide and 13:1 using the chloride. In contrast to ara-A, compound 1 is not deaminated by adenosine deaminase.