TY  - JOUR
A1  - Kleinpeter, Erich
A1  - Werner, Peter
A1  - Linker, Torsten
T1  - Synthesis and NMR spectroscopic conformational analysis of benzoic acid esters of mono- and 1,4-dihydroxycyclohexane, 4-hydroxycyclohexanone and the -ene analogue - The more polar the molecule the more stable the axial conformer
JF  - Tetrahedron
N2  - para-Substituted benzoic acid esters of cyclohexanol, 1,4-dihydroxycyclohexane, 4-hydroxy-cyclohexanone and of the corresponding exo-methylene derivative were synthesized and the conformational equilibria of the cyclohexane skeleton studied by low temperature H-1 and C-13 NMR spectroscopy. The geometry optimized structures of the axial/equatorial chair conformers were computed at the DFT level of theory. Only one preferred conformation of the ester group was obtained for both the axial and the equatorial conformer, respectively. The content of the axial conformer increases with growing polarity of the 6-membered ring moiety; hereby, in addition, the effect of sp(2) hybridization/polarity of C(4)= O/C(4)= CH2 on the present conformational equilibria is critically evaluated. Another dynamic process could be studied, for the first time in this kind of compounds. (C) 2017 Elsevier Ltd. All rights reserved.
KW  - Conformational analysis
KW  - A-values of COOAr on cyclohexane
KW  - Benzoic acid esters
KW  - Dynamic NMR
KW  - DFT calculations
Y1  - 2017
U6  - https://doi.org/10.1016/j.tet.2017.04.029
SN  - 0040-4020
VL  - 73
SP  - 3801
EP  - 3809
PB  - Elsevier
CY  - Oxford
ER  -