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The γ‐butyrolactone ring puckering
Author(s) -
Galache M. P.,
Garcés P.,
Esteban A. L.,
Diez E.,
Guilleme J.
Publication year - 1989
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.1260270108
Subject(s) - chemistry , ring (chemistry) , envelope (radar) , molecule , crystallography , stereochemistry , spectral line , physics , organic chemistry , telecommunications , radar , computer science , astronomy
Abstract The 60 and 100 MHz 1 H NMR spectra of γ‐butyrolactone were analysed in detail. The best set of coupling values (Hz ± 0.03) is 3 J AB c= 7.86, 3 J AB t= 6.27, 3 J BC c= 9.52, 3 J BC t= 6.86, 4 J AC c+ 4 J AC t= −0.18, 2 J A − 2 J B = 3.89 and 2 J B − 2 J C = 4.86 (A, B and C refer to α, β and γ protons, with respect to the ring oxygen, and c and t mean the same and opposite side of the ring, respectively). The 3 J values support the conclusion that the molecule is interconverting between two equivalent conformations of near envelope type with the β‐carbon out of the mean plane defined by the fragment COCOC.