title: Approaches to polycyclic 1,4-dioxygenated xanthones. Application to total synthesis of the aglycone of IB-00208.
abstract: Hexacyclic xanthone natural products such as IB-00208 present a formidable challenge in organic synthesis. A new approach to polycyclic 1,4-dioxygenated xanthones from benzocyclobutenones has been developed and applied to the first total synthesis of the aglycone of IB-00208. The 22-step synthesis features an acetylide stitching process that joins an aryl aldehyde with an angularly fused benzocyclobutenone, which was prepared by a ring-closing metathesis reaction. The resulting acetylenic benzocyclobutenone diol underwent a Moore rearrangement to give an intermediate that was further elaborated to the aglycone of IB-00208 as a mixture of hydroquinone-quinone tautomers.
authors.affiliation: Department of Chemistry, University of Texas at Austin , Austin, Texas 78712, United States.
authors.forename: Jingyue
authors.initials: J
authors.lastname: Yang
authors.forename: Daniel
authors.initials: D
authors.lastname: Knueppel
authors.forename: Bo
authors.initials: B
authors.lastname: Cheng
authors.forename: Douglas
authors.initials: D
authors.lastname: Mans
authors.forename: Stephen F
authors.initials: SF
authors.lastname: Martin
mesh_terms: D000438:Alcohols / Q000737:chemistry; D001688:Biological Products / Q000138:chemical synthesis* / Q000737:chemistry; D005960:Glucosides / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D014966:Xanthenes / Q000138:chemical synthesis* / Q000737:chemistry; D044004:Xanthones / Q000737:chemistry*
chemical_list: D000438:Alcohols; D001688:Biological Products; D005960:Glucosides; C474717:IB 00208; D014966:Xanthenes; D044004:Xanthones