title: Total synthesis of (±)-lundurine B.
abstract: A total synthesis of (±)-lundurine B was accomplished. A combination of stereoselective intramolecular cyclopropane formation and aryl amination furnished cyclopropane-fused indoline stereoselectively. Ring-closing metathesis (RCM) of siloxy diene and intramolecular aminoacetal formation followed by bridgehead vinylation of an anti-Bredt iminium cation led to the construction of six- and seven-membered rings with a quaternary carbon center. After the formation of dihydropyrrole by RCM, the Boc-protecting group of indoline was converted into the corresponding methyl carbamate via silyl carbamate to complete the total synthesis of (±)-lundurine B. The characteristic rearrangement of the cyclopropane-fused indoline skeleton is also described.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Chiba University , 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Hoshi
authors.forename: Osamu
authors.initials: O
authors.lastname: Kaneko
authors.forename: Masaya
authors.initials: M
authors.lastname: Nakajima
authors.forename: Shigeru
authors.initials: S
authors.lastname: Arai
authors.forename: Atsushi
authors.initials: A
authors.lastname: Nishida
mesh_terms: D000586:Amination; D003521:Cyclopropanes / Q000737:chemistry*; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D011083:Polycyclic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D003521:Cyclopropanes; D007211:Indoles; D011083:Polycyclic Compounds; C000590471:lundurine B; C057812:indoline; C030797:cyclopropane