title: Synthetic studies on cyathins: enantioselective total synthesis of (+)-allocyathin B2.
abstract: [reaction: see text] The enantioselective total synthesis of (+)-allocyathin B(2) has been achieved. Our approach features a convergent enantioselective construction of the 5-6-7 tricyclic core system using the originally developed chiral building blocks via asymmetric catalysis, the intramolecular aldol reaction in high yield, successful samarium diiodide-mediated ring expansion, and a newly developed double-bond installation method.
authors.affiliation: Department of Chemistry, School of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Takano
authors.forename: Akinori
authors.initials: A
authors.lastname: Umino
authors.forename: Masahisa
authors.initials: M
authors.lastname: Nakada
mesh_terms: D002384:Catalysis; D003500:Cyclization; D004224:Diterpenes / Q000138:chemical synthesis* / Q000737:chemistry; D008968:Molecular Conformation; D013237:Stereoisomerism
chemical_list: D004224:Diterpenes; C430643:allocyathin B2; C007179:cyathins