title: Synthesis of the unique angular tricyclic chromone structure proposed for aspergillitine, and its relationship with alkaloid TMC-120B.
abstract: The synthesis of the tricyclic angular chromone structure originally assigned to aspergillitine is reported. The synthesis was achieved in 11 steps and 15% overall yield from 2,4-dihydroxypropiophenone, through the intermediacy of 2,3-dimethyl-7-hydroxychromen-4-one. Construction of the nitrogen-bearing heterocyclic ring entailed a Stille cross-coupling reaction with n-Bu(3)SnCH(2)CH=CH(2), followed by double bond isomerization, oximation of the chromone carbonyl, and a final microwave-assisted electrocyclization of the thus formed 6π-electron aza-triene system.
authors.affiliation: Institute of Chemistry of Rosario (IQUIR, CONICET-UNR) and School of Biochemical and Pharmaceutical Sciences, National University of Rosario, Suipacha 531, S2002LRK Rosario, Argentina.
authors.forename: Sebastián O
authors.initials: SO
authors.lastname: Simonetti
authors.forename: Enrique L
authors.initials: EL
authors.lastname: Larghi
authors.forename: Andrea B J
authors.initials: AB
authors.lastname: Bracca
authors.forename: Teodoro S
authors.initials: TS
authors.lastname: Kaufman
mesh_terms: D000470:Alkaloids / Q000737:chemistry*; D001572:Benzofurans / Q000737:chemistry*; D002867:Chromones / Q000138:chemical synthesis / Q000737:chemistry*; D006575:Heterocyclic Compounds, 3-Ring / Q000138:chemical synthesis*; D007546:Isoquinolines / Q000737:chemistry*; D015394:Molecular Structure
chemical_list: D000470:Alkaloids; D001572:Benzofurans; D002867:Chromones; D006575:Heterocyclic Compounds, 3-Ring; D007546:Isoquinolines; C402697:TMC 120B; C474263:aspergillitine