TY  - JOUR
A1  - Kleinpeter, Erich
A1  - Laemmermann, Anica
A1  - Kühn, Heiner
T1  - Synthesis and NMR spectra of the syn and anti isomers of substituted cyclobutanes-evidence for steric and spatial hyperconjugative interactions
JF  - Tetrahedron
N2  - The syn and anti isomers of cis,cis-tricyclo[5.3.0.0(2.6)]dec-3-ene derivatives have been synthesized and their (1)H and (13)C NMR spectra unequivocally analyzed. Both their structures and their (1)H and (13)C NMR chemical shifts were calculated by DFT, the latter two calculations employing the GIAO perturbation method. Additionally, calculated NMR shielding values were partitioned into Lewis and non-Lewis contributions from the bonds and lone pairs involved in the molecules by accompanying NBO and NCS analyses. The differences between the syn and anti isomers were evaluated with respect to steric and spatial hyperconjugation interactions.
KW  - Conformational analysis
KW  - cis,cis-Tricyclo[5.3.0.0(2,6)]dec-3-enes
KW  - NMR
KW  - DFT calculation
KW  - NBO/NCS analysis
Y1  - 2011
U6  - https://doi.org/10.1016/j.tet.2011.02.012
SN  - 0040-4020
VL  - 67
IS  - 14
SP  - 2596
EP  - 2604
PB  - Elsevier
CY  - Oxford
ER  -