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1 H and 13 C NMR studies of some aromatic dilactones (precursors of paracyclophanes)
Author(s) -
SolladiéCavallo Arlette,
Hilbert Marcel
Publication year - 1981
Publication title -
organic magnetic resonance
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0030-4921
DOI - 10.1002/mrc.1270170321
Subject(s) - chemistry , enantiomer , crystallography , aromaticity , proton nmr , activation energy , nmr spectra database , carbon 13 nmr , stereochemistry , spectral line , activation barrier , molecule , organic chemistry , physics , astronomy
Carbon‐13 and proton NMR data of macrocyclic diaromatic dilactones are presented. The observed behaviour of the spectra as a function of temperature shows that the energy barrier for the re‐orientation of the side chains is lower than 49 kJ mol −1 (12 kcal mol −1 ) and that the energy barrier for the rotation of the aromatic rings is larger than 99 kJ mol −1 (24 kcal mol −1 ). Hence, chiral substituted dilactones of this type will be resolvable, and the enantiomers can be easily handled at room temperature.