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1 H and 13 C NMR study of the neomenthyl halides: A very high field proton shift in the iodide
Author(s) -
Lange Gordon L.,
Gottardo Christine
Publication year - 1990
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.1260280719
Subject(s) - chemistry , bromide , iodide , halogen , halide , nmr spectra database , chemical shift , proton , proton nmr , spectral line , carbon 13 nmr , chloride , stereochemistry , inorganic chemistry , organic chemistry , alkyl , physics , astronomy , quantum mechanics
Complete analyses o the 1 H NMR spectra of neomethyl iodide (1), the bromide (2) and the chloride (3) are reported. Of paticular interest is the very high‐field resonance at −0.16 ppm in 1 which is assigned to H‐4. The same poton in the bromide is also found upfield at 0.78 ppm. H‐4 in these neomenthyl derivatives is tertiary and β‐antipeiplanar to the halogen atom. A similar upfield shift has been reported previously for the tertiary proton in trans ‐9‐iododecalin. The reasons or these unusual shifts are not readily apparent and the 13 C NMR spectra of 1 and 2, which are reported here for the first time, provide no additional clues to explain the shifts.