Structure of the products of condensation of hydroxylamine with trifluoromethyl-β-diketones: assignments of the diastereotopic protons of the 4-methylene group in 5-hydroxy-5-trifluoromethyl-Δ2-isoxazolines

✍ Scribed by Dionisia Sanz; Rosa M. Claramunt; Shiv P. Singh; Vinod Kumar; Ranjana Aggarwal; José Elguero; Ibon Alkorta

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 106 KB
• Volume: 43
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/mrc.1676

✦ Synopsis

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.