title: Synthesis of the A,B,C-ring system of hexacyclinic acid.
abstract: [structure: see text] The synthesis of the A,B,C-ring system (2) of hexacyclinic acid (1) is achieved starting from a selective Diels-Alder reaction followed by vinyl cuprate addition. The diastereoselective reduction of the ketone carbonyl at C16 could be achieved with LiAlH(4). An intramolecular Michael addition established the ring system stereoselectively, providing access to the selective generation of 9 out of the 14 stereocenters of hexacyclinic acid.
authors.affiliation: Institut für Organische Chemie, Universität Hannover, Schneiderberg 1 B, 30167 Hannover, Germany.
authors.forename: Timo
authors.initials: T
authors.lastname: Stellfeld
authors.forename: Ulhas
authors.initials: U
authors.lastname: Bhatt
authors.forename: Markus
authors.initials: M
authors.lastname: Kalesse
mesh_terms: D003300:Copper / Q000737:chemistry; D003500:Cyclization; D006576:Heterocyclic Compounds, 4 or More Rings / Q000138:chemical synthesis*; D007202:Indicators and Reagents; D015394:Molecular Structure; D013237:Stereoisomerism; D013302:Streptomyces / Q000737:chemistry*; D014753:Vinyl Compounds / Q000737:chemistry
chemical_list: D006576:Heterocyclic Compounds, 4 or More Rings; D007202:Indicators and Reagents; D014753:Vinyl Compounds; C502347:hexacyclinic acid; D003300:Copper