NMR 1,3 Dialxial deshielding effect of the hydroxyl group on ring hydrogens studied from partially deuterated six-membersed ring compunds
✍ Scribed by Alain C. Huitric; John B. Carr; William F. Trager
- Publisher
- John Wiley and Sons
- Year
- 1966
- Tongue
- English
- Weight
- 258 KB
- Volume
- 55
- Category
- Article
- ISSN
- 0022-3549
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✦ Synopsis
T h e deshielding effect of the hydroxyl group o n axial ring protons through 1,3diaxial spatial interaction has been studied in truns-~-o-tolyl-truns-5-hydroxycyclo- hexanol-3,3,6,6-d4 (11) andtruns-2-o-tolyl-cis-4-hydroxycyclohexanol-3,3,6,6-d~ (HI) in deuterated chloroform, acetone-& methanol-&, acetic acid, and pyridine; in 4-tert-butyl-trans-~,4-cyclohexanediol-3,3,5,~-~~ (VI) in m e t h a n o l 4 and pyridine;
and in 4-tert-butyl-cis-1,4-cyclohexanediol-~,3,~,5-d4 (VII) in pyridine. A consistent downfield shift of about 0.50 p.p.m. was found for the signal of H-1 of If in the first 4 solvents, but a considerably larger shift of 0.90 p.p.m. was obtained in pyridine. A downfield shift of about 0.58 f 0.05 p.p.m. was found for the signal of H-2 in I11 in the first 4 solvents while a shift of 0.97 p.p.m. was obtained in pyridine. The deshielding effect of the tertiary hydroxyl groups in VI and VII was found to he smaller than that of the secondary hydroxyl in I1 and 111 in a given solvent, hut the magnitude of the pyridine solvent effect was about the same in the 2 series.
HE DBSIIIELDISG effect of the hydroxyl group T through 1, 3-diaxial spatial interaction is well