Doi: 10.1002/mrc.1676

The structure of the products of condensation of hydroxylamine with trifluoromethyl-b-diketones: assignments of the diastereotopic protons of the 4-methylene group in 5-hydroxy-5-trifluoromethyl-D2-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-Δ²-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-Δ²-pyrazolines and the corresponding 5-trichloromethyl derivatives.