A. Katritzky, N. Akhmedov, I. Ghiviriga
Mar 1, 2003
Citations
0
Influential Citations
4
Citations
Journal
Journal of Physical Organic Chemistry
Abstract
Assignments of the proton and carbon NMR signals for 2-(benzotriazol-1-yl)tetrahydrofurans 1-6 are based on 1 H- 1 H COSY, NOESY, 1 H- 1 3 C heteronuclear HETCOR, 1 H- 1 3 C heteronuclear long-range HETCOR-LR and nuclear Overhauser enhancement experiments, and supported by selective spin decoupling experiments. The electronic and steric effects of the 2-benzotriazolyl substituent on the H and 1 3 C NMR chemical shifts are evaluated and discussed. Conformational isomers cis and trans are distinguished by the magnitude of the J ( H - 2 , H - 3 ) coupling constant, by one-bond 1 J ( C - 2 , H - 2 ) coupling constants and by 1 3 C chemical shifts of the C-2 anomeric carbon. The benzotriazol-1-yl group prefers the pseudo-axial orientation in each of 1-6. The stereochemistry and conformation of 6 are rigorously demonstrated by an x-ray structure.