Synthesis of All Eight L‐Glycopyranosyl Donors Using CH Activation |
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Authors: | Tobias Gylling Frihed Prof Christian Marcus Pedersen Prof Mikael Bols |
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Institution: | Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen ? (Denmark) |
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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(sp3)? H activation on sulfide‐containing compounds. |
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Keywords: | C H activation Fleming– Tamao oxidation glycosyl donors iridium catalysis L‐hexoses |
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