title: Enantioselective synthesis of the C10-C20 fragment of fusicoccin A.
abstract: A synthesis of the fully protected C-ring fragment of the tricyclic diterpene fusicoccin A is reported. The desired cyclopentenyl halides 5a,b are obtained in a total of nine steps. Key transformations of the synthesis sequence are a nonconventional Cr-catalyzed allylic oxidation of a protected intermediate cylcopentenone, a diastereoselective addition of a propenyl Grignard/CeCl(3) reagent to the unmasked cyclopentenone, and an asymmetric hydroboration of the isopropenyl substituent. The protected and suitably functionalized C-ring fragment paves the way to explore further the total synthesis of fusicoccin A.
authors.affiliation: Fakultät Chemie, Chemische Biologie, Technische Universität Dortmund, Otto-Hahn-Strasse 6, 44221 Dortmund, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Richter
authors.forename: Christian
authors.initials: C
authors.lastname: Hedberg
authors.forename: Herbert
authors.initials: H
authors.lastname: Waldmann
mesh_terms: D002384:Catalysis; D003517:Cyclopentanes / Q000737:chemistry*; D004224:Diterpenes / Q000138:chemical synthesis* / Q000737:chemistry; D006027:Glycosides / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D010084:Oxidation-Reduction; D013237:Stereoisomerism
chemical_list: D003517:Cyclopentanes; D004224:Diterpenes; D006027:Glycosides; C007808:fusicoccin; C013905:cyclopentenone