title: Total Synthesis of the Antiviral Natural Product Houttuynoid B.
abstract: The first total synthesis of houttuynoid B, a powerful antiviral flavonoid glycoside from the Chinese plant Houttuynia cordata, is described. In a key step, a Baker-Venkataraman rearrangement employing an already glycosylated substrate was used to efficiently set up the fully functionalized carbon skeleton. The required benzofuran building block was prepared through a domino Sonogashira coupling/5-endo-dig cyclization and converted into a stable 1-hydroxybenzotriazole-derived active ester prior to linking with a galactosylated hydroxyacetophenone unit. The elaborated synthesis requires only nine steps (11 % overall yield) along the longest linear sequence and paves the way for the preparation of structurally related compounds for further biological evaluation.
authors.affiliation: Department of Chemistry, University of Cologne, Greinstrasse 4, 50939, Köln, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Kerl
authors.affiliation: Department of Chemistry, University of Cologne, Greinstrasse 4, 50939, Köln, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Berger
authors.affiliation: Department of Chemistry, University of Cologne, Greinstrasse 4, 50939, Köln, Germany. schmalz@uni-koeln.de.
authors.forename: Hans-Günther
authors.initials: HG
authors.lastname: Schmalz
mesh_terms: D000998:Antiviral Agents / Q000138:chemical synthesis* / Q000737:chemistry; D001686:Biological Phenomena; D003500:Cyclization; D005419:Flavonoids / Q000138:chemical synthesis* / Q000737:chemistry; D006027:Glycosides / Q000138:chemical synthesis / Q000737:chemistry*; D015394:Molecular Structure; D014230:Triazoles / Q000737:chemistry*
chemical_list: D000998:Antiviral Agents; D005419:Flavonoids; D006027:Glycosides; D014230:Triazoles; C000609049:houttuynoid B; C011852:1-hydroxybenzotriazole
keywords: antiviral agents; benzofurans; cross-coupling; flavonoids; glycosides