Vinigrol: a compact, diene-transmissive Diels-Alder strategy to the tricyclic core.
A short (six steps from 17), versatile route to the tricyclic core of Vinigrol is described. A Lewis acid catalyzed and self-assembled Diels-Alder (LACASA-DA) reaction from the homoallylic cross-conjugated trienol 15 with N-methylmaleimide afforded the monoadduct 17 with diastereo-, regio-, and chemoselective control. Oxidation and installation of an acetylene (Ohira's reagent) followed by further manipulations afforded trienone 24. The second intramolecular Diels-Alder (at 45 degrees C) reaction assembled the tricyclic skeleton 25 directly. The configuration of 25 was confirmed by X-ray analysis.
Souweha
Michael Santos
MS
Department of Chemistry, University of Ottawa, 10 Marie Curie, Ottawa, Ontario, Canada K1N 6N5.
Enright
Gary D
GD
Fallis
Alex G
AG
D018360:Crystallography, X-Ray; D004224:Diterpenes / Q000138:chemical synthesis* / Q000737:chemistry; D006575:Heterocyclic Compounds, 3-Ring / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure
D004224:Diterpenes; D006575:Heterocyclic Compounds, 3-Ring; C055112:vinigrol