title: Total synthesis of siomycin A: construction of synthetic segments.
abstract: The five practical segments for the total synthesis of siomycin A, that is, the dehydropiperidine segment A (5), the pentapeptide segment B (3), the dihydroquinoline segment C (6), and the beta-phenylselenoalanine dipeptide segments D (7) and E (4), were synthesized. Segment A (5) was constructed by the coupling of the azomethine ylide and the chiral sulfinimine, followed by the stereoselective reduction of the six-membered imine function. Segment B (3) was synthesized by the phenylselenylation of the beta-lactone, stereoselective vinylzinc addition to the chiral sulfinimine, and oxazoline-thioamide conversion. Segment C (6) was prepared by the one-pot olefination of the tetrahydroquinoline N-oxide using triflic anhydride and triethylamine, stereoselective reduction of the methyl ketone function, and regioselective Yb(OTf)(3)-catalyzed epoxide opening by the amino group. Segments D (7) and E (4) were synthesized by coupling of the properly protected beta-phenylselenoalanines.
authors.affiliation: Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Mori
authors.forename: Shuhei
authors.initials: S
authors.lastname: Higashibayashi
authors.forename: Taiji
authors.initials: T
authors.lastname: Goto
authors.forename: Mitsunori
authors.initials: M
authors.lastname: Kohno
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Satouchi
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Shinko
authors.forename: Kengo
authors.initials: K
authors.lastname: Suzuki
authors.forename: Shunya
authors.initials: S
authors.lastname: Suzuki
authors.forename: Hiraku
authors.initials: H
authors.lastname: Tohmiya
authors.forename: Kimiko
authors.initials: K
authors.lastname: Hashimoto
authors.forename: Masaya
authors.initials: M
authors.lastname: Nakata
mesh_terms: D000475:Alkenes / Q000737:chemistry; D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry; D018360:Crystallography, X-Ray; D006873:Hydroquinones / Q000737:chemistry; D007097:Imines / Q000737:chemistry; D008956:Models, Chemical; D008958:Models, Molecular; D015394:Molecular Structure; D010455:Peptides / Q000138:chemical synthesis* / Q000737:chemistry; D011759:Pyrrolidines / Q000737:chemistry; D013237:Stereoisomerism; D013438:Sulfhydryl Compounds / Q000737:chemistry; D013452:Sulfonium Compounds / Q000737:chemistry
chemical_list: D000475:Alkenes; D000900:Anti-Bacterial Agents; D006873:Hydroquinones; D007097:Imines; D010455:Peptides; D011759:Pyrrolidines; D013438:Sulfhydryl Compounds; D013452:Sulfonium Compounds; C522016:sulfinimine; C024711:siomycin A; C031927:hydroquinone