title: Structure of the products of condensation of hydroxylamine with trifluoromethyl-beta-diketones: assignments of the diastereotopic protons of the 4-methylene group in 5-hydroxy-5-trifluoromethyl-delta2-isoxazolines.
abstract: The combined use of 1H NMR spectroscopy with theoretical calculations of chemical shifts (GIAO) and coupling constants (B3LYP/6-311 ++G**) of a 5-hydroxy-5-trifluoromethyl-Delta2-isoxazoline has enabled solving the problem of the assignments of the diastereotopic protons in this compound. This result has been extended to 5-hydroxy-5-trifluoromethyl-Delta2-pyrazolines and the corresponding 5-trichloromethyl derivatives.
authors.affiliation: Departamento de Química Orgánica y Bio-Orgánica, Universidad Nacional de Educación a Distancia (UNED), Facultad de Ciencias, Senda del Rey 9, E-28040 Madrid, Spain. dsanz@ccia.uned.es
authors.forename: Dionisia
authors.initials: D
authors.lastname: Sanz
authors.forename: Rosa M
authors.initials: RM
authors.lastname: Claramunt
authors.forename: Shiv P
authors.initials: SP
authors.lastname: Singh
authors.forename: Vinod
authors.initials: V
authors.lastname: Kumar
authors.forename: Ranjana
authors.initials: R
authors.lastname: Aggarwal
authors.forename: José
authors.initials: J
authors.lastname: Elguero
authors.forename: Ibon
authors.initials: I
authors.lastname: Alkorta
mesh_terms: D005461:Fluorine / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry*; D019811:Hydroxylamine / Q000737:chemistry*; D007555:Isoxazoles / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D015394:Molecular Structure; D011522:Protons
chemical_list: D007555:Isoxazoles; D007659:Ketones; D011522:Protons; D005461:Fluorine; D019811:Hydroxylamine; D006859:Hydrogen