title: Synthesis of all eight L-glycopyranosyl donors using C-H activation.
abstract: The synthesis of all eight rare, but biologically important L-hexoses as the according thioglycosyl donors was achieved through a procedure involving the C-H activation of their corresponding 6-deoxy-L-hexoses. The key steps of the procedure were the silylation of the OH group at C4 followed by an intramolecular C-H activation of the methyl group in γ-position; both steps were catalyzed by iridium. The following Fleming-Tamao oxidation and acetylation gave the suitably protected L-hexoses. This is the first general method for the preparation of all eight L-hexoses as their thioglycosyl donors ready for glycosylation and the first example of an iridium-catalyzed C(sp(3))-H activation on sulfide-containing compounds.
authors.affiliation: Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen Ø (Denmark).
authors.forename: Tobias Gylling
authors.initials: TG
authors.lastname: Frihed
authors.forename: Christian Marcus
authors.initials: CM
authors.lastname: Pedersen
authors.forename: Mikael
authors.initials: M
authors.lastname: Bols
mesh_terms: D002244:Carbon / Q000737:chemistry; D006601:Hexoses / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry
chemical_list: D006601:Hexoses; D002244:Carbon; D006859:Hydrogen
keywords: CH activation; Fleming-Tamao oxidation; L-hexoses; glycosyl donors; iridium catalysis