Synthesis of the First Selenium‐Containing Acyclic Nucleosides and Anomeric Spironucleosides from Carbohydrate Precursors

We report the synthesis of acyclic and spiranic imidazole‐derived C ‐selenonucleosides. 5‐Hydroxy‐4‐tetrahydroxybutyl imidazolidine‐2‐selones, a novel class of acyclic selenonucleosides, were transformed into (tetrahydroxybutylimidazol‐2‐yl)diselenide, by acetylation and chemoselective N ‐deacetylation with methanolic imidazole. Furthermore, the synthesis of a new class of conformationally restricted arabino ‐configured spironucleosides containing an imidazolidine‐2‐selone unit around the glycosidic bond was achieved, starting from N ‐fructosamines, via 4‐hydroxy‐4‐tetrahydoxybutyl‐imidazolidine‐2‐selones as the key intermediates. Acetylation–deacetylation of these intermediates gave access to stable aromatic imidazoline‐2‐selones.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)