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.
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.
Sanz
Dionisia
D
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
Claramunt
Rosa M
RM
Singh
Shiv P
SP
Kumar
Vinod
V
Aggarwal
Ranjana
R
Elguero
José
J
Alkorta
Ibon
I
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
D007555:Isoxazoles; D007659:Ketones; D011522:Protons; D005461:Fluorine; D019811:Hydroxylamine; D006859:Hydrogen