Stereodivergent access to α- and β-azanucleosides <i>via</i> catalyst-free, achiral modulator-controlled iodocyclization: a concise synthesis of forodesine.

ABSTRACT: Stereoselective glycosidic bond formation remains a major challenge in nucleoside synthesis. Azanucleosides, a prominent class of nucleoside analogs wherein the sugar oxygen is replaced by nitrogen, exhibit unique biological activities but struggle to achieve anomeric selectivity in synthesis. We disclose a catalyst-free iodocyclization strategy that uses simple achiral molecules-NaI or 2-mercaptobenzimidazole-to stereodivergently access both α- and β-azanucleosides in high yields (up to 98%) with excellent stereocontrol (β : α up to β only and α : β up to 19 : 1). The utility of this method is demonstrated by a concise synthesis of forodesine in 8 steps with 20% overall yield and >20 : 1 β : α selectivity-the shortest route and highest ster

SUBMITTER: Zhong Y 

PROVIDER: S-EPMC12771107 | biostudies-literature | 2026 Feb

REPOSITORIES: biostudies-literature