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Configurational effects in 17 O NMR chemical shifts of hydroxyl‐substituted, bicyclo [2.2.1]heptenes and ‐heptanes, their methylated derivatives and some related compounds
Author(s) -
Kolehmainen Erkki,
Laihia Katri
Publication year - 1993
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.1260310814
Subject(s) - chemistry , chemical shift , alicyclic compound , carbon 13 nmr , nmr spectra database , acetonitrile , shielding effect , bicyclic molecule , van der waals force , spectral line , computational chemistry , stereochemistry , medicinal chemistry , organic chemistry , molecule , physics , astronomy , layer (electronics)
Well resolved natural abundance 17 O NMR spectra of 27 mono‐, di‐, tri‐ and tetrahydroxybicyclo[2.2.1]heptenes and ‐heptanes (norbornenes or norbornanes), their methylated derivatives and some related compounds were measured for 0.5 M or saturated solutions in acetonitrile at 65°C. In addition, the 17 O NMR chemical shifts of 14 aliphatic and alicyclic alcohols were also determined for reference purposes. The 17 O NMR chemical shifts of all compounds were assigned. Both methyl‐ and hydroxyl‐induced deshielding β‐effects were consistent with those reported in the literature. Similarly, observed shielding γ‐effects were in agreement with the earlier observations and characteristic especially for mutual γ‐ gauche and ‐eclipsed orientations of substituents. In addition, clear shielding δ‐effects (up to 10 ppm) were observed in tri‐ or tetrahydroxynorbornanes. These δ‐effects can be related to the attractive van der Waals interactions observed earlier in 13 C NMR chemical shifts.