title: An enantioselective total synthesis of helioporins C and E.
abstract: A short and enantioselective total synthesis of helioporins C and E, which are bioactive marine diterpenes containing a serrulatane or amphilectane skeleton, was elaborated. The chirogenic step, i.e. a Cu(I)-catalyzed allylic alkylation of a cinnamyl chloride with methylmagnesium bromide, proceeded with virtually complete enantioselectivity (99% ee) in the presence of a chiral phosphine-phosphite ligand. The other stereocenters were diastereoselectively established through Me(2)AlCl-mediated cationic cyclization and Ir-catalyzed hydrogenation.
authors.affiliation: Department of Chemistry, University of Cologne, Greinstrasse 4, 50939 Köln, Germany.
authors.forename: Wibke
authors.initials: W
authors.lastname: Lölsberg
authors.forename: Susen
authors.initials: S
authors.lastname: Werle
authors.forename: Jörg-Martin
authors.initials: JM
authors.lastname: Neudörfl
authors.forename: Hans-Günther
authors.initials: HG
authors.lastname: Schmalz
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000737:chemistry; D002384:Catalysis; D003500:Cyclization; D004224:Diterpenes / Q000138:chemical synthesis* / Q000737:chemistry; D008386:Marine Biology; D013237:Stereoisomerism
chemical_list: D004224:Diterpenes; C578359:helioporin C; C413806:helioporin E