title: Total Synthesis of (-)-Isoschizogamine.
abstract: The total synthesis of (-)-isoschizogamine was accomplished, featuring the construction of the quaternary carbon center by the modified Johnson-Claisen rearrangement in basic media and the facile assembly of the key tetracyclic quinolone intermediate through a cascade cyclization. The characteristic cyclic aminal was constructed by late-stage C-H functionalization at the position adjacent to the lactam nitrogen using a combination of CrO3 and nBu4 NIO4 and subsequent Bi(OTf)3 -mediated cyclization.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba 6-3, Aramaki, Aoba-ku, Sendai 980-8578 (Japan), Fax: (+81) 22-795-6877.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Takada
authors.affiliation: Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba 6-3, Aramaki, Aoba-ku, Sendai 980-8578 (Japan), Fax: (+81) 22-795-6877.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Fujiwara
authors.affiliation: Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba 6-3, Aramaki, Aoba-ku, Sendai 980-8578 (Japan), Fax: (+81) 22-795-6877.
authors.forename: Kenji
authors.initials: K
authors.lastname: Sugimoto
authors.affiliation: Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba 6-3, Aramaki, Aoba-ku, Sendai 980-8578 (Japan), Fax: (+81) 22-795-6877.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Ueda
authors.affiliation: Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba 6-3, Aramaki, Aoba-ku, Sendai 980-8578 (Japan), Fax: (+81) 22-795-6877. tokuyama@mail.pharm.tohoku.ac.jp.
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Tokuyama
mesh_terms: D003500:Cyclization; D006860:Hydrogen Bonding; D026121:Indole Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry; D008698:Mesylates / Q000737:chemistry; D009861:Onium Compounds / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D026121:Indole Alkaloids; D008698:Mesylates; D009861:Onium Compounds; C409122:isoschizogamine; C445789:Bi(OTf)3
keywords: CH functionalization; alkaloids; aminal; cascade reaction; total synthesis