title: Stereoselective synthesis of 1-nitrobicyclo[3.1.0]hexanes and fused isoxazoline-N-oxides from primary nitro compounds.
abstract: The one-step preparation of 1-nitrobicyclo[3.1.0]hexane and bicycloisoxazoline-N-oxide was readily achieved from conjugate adducts of nitro alkenes and allylmalonates by treatment with Ag(2)O and iodine under basic conditions. We observed that when a primary alkyl group was present at the β-position of the nitro group, bicyclo[3.1.0]hexane was preferentially formed, whereas if a secondary alkyl group occupied that position, isoxazoline-N-oxide was predominantly produced. High cis-selectivity was observed for the formation of cyclopentane units for both reactions. An iodomethyl adduct, considered an intermediate of the cyclization, was isolated, and its conversion to isoxazoline-N-oxide was successfully achieved. The isoxazoline-N-oxide underwent 1,3-dipolar cycloaddition with alkenes to yield tricycloheterocyclic compounds, which were readily converted to spirolactam in good yield by reductive cleavage of N-O bonds using Raney-Ni. On the other hand, 1,3-dipolar cycloaddition of the isoxazoline-N-oxide to terminal alkynes yielded tricyclic aziridines stereoselectively.
authors.affiliation: Department of Applied Molecular Bioscience, Graduate School of Medicine, Yamaguchi University, Ube 755-8611, Japan. ak10@yamaguchi-u.ac.jp
authors.forename: Akio
authors.initials: A
authors.lastname: Kamimura
authors.forename: Ryota
authors.initials: R
authors.lastname: Takeuchi
authors.forename: Kosuke
authors.initials: K
authors.lastname: Ikeda
authors.forename: Takaaki
authors.initials: T
authors.lastname: Moriyama
authors.forename: Michinori
authors.initials: M
authors.lastname: Sumimoto
mesh_terms: D001643:Bridged Bicyclo Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D003497:Cyclic N-Oxides / Q000737:chemistry*; D007555:Isoxazoles / Q000737:chemistry*; D015394:Molecular Structure; D009574:Nitro Compounds / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: C572698:1-nitrobicyclo(3.1.0)hexane; D001643:Bridged Bicyclo Compounds; D003497:Cyclic N-Oxides; D007555:Isoxazoles; D009574:Nitro Compounds