title: Photoreactions of bicyclic aziridines with alkenes and alkynes: a novel synthetic methodology for 8-azabicyclo[3.2.1]octane derivatives.
abstract: The photochemical C-C bond cleavage of bicyclic aziridines 7 and subsequent [3 + 2] cycloaddition with electron-deficient alkenes and alkynes afforded the novel head-to-head adducts selectively and efficiently. The adducts contain the naturally occurring 8-azabicyclo[3.2.1]octane skeleton (e.g. tropane alkaloids). The aziridine 8 fused with a 6-membered ring also afforded the cycloadducts but in poor yields. The methylaziridine 9 reacted with an electron-deficient alkene, affording the head-to-tail adduct 23 in addition to head-to-head adducts 22a and 22b. The photoreactions of bicyclic aziridines with alkenes and alkynes indicate a similar behavior to that of aziridines with a linear chain.
authors.affiliation: Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo, 204-8588, Japan. ishiikei@my-pharm.ac.jp
authors.forename: Keitaro
authors.initials: K
authors.lastname: Ishii
authors.forename: Motohiro
authors.initials: M
authors.lastname: Kido
authors.forename: Masahiro
authors.initials: M
authors.lastname: Noji
authors.forename: Shigeo
authors.initials: S
authors.lastname: Sugiyama
mesh_terms: D000475:Alkenes / Q000737:chemistry*; D000480:Alkynes / Q000737:chemistry*; D001388:Aziridines / Q000737:chemistry*; D001643:Bridged Bicyclo Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D003500:Cyclization; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D010777:Photochemistry; D014326:Tropanes / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D000475:Alkenes; D000480:Alkynes; D001388:Aziridines; D001643:Bridged Bicyclo Compounds; D014326:Tropanes; C033132:aziridine