Application of 1J(C,H) coupling constants in conformational analysis

被引：34

作者：

Kleinpeter, E

Koch, A

Pihlaja, K

机构：

[1] Univ Potsdam, Dept Chem, D-14415 Potsdam, Germany

[2] Univ Turku, Dept Chem, FIN-20500 Turku, Finland

来源：

TETRAHEDRON | 2005年 / 61卷 / 31期

关键词：

(1)J(C; Hax; equ) coupling constants; conformational analysis; NMR; 1,3-dioxanes; 1,3-oxathianes; 1,3-dithianes; theoretical calculations; GIAO; Perlin effect;

D O I：

10.1016/j.tet.2005.05.083

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

Conformational equilibria for a number of methyl substituted 1,3-dioxanes 1, 1,3-oxathianes 2 and 1,3-dithianes 3 were calculated at the HF and DFT levels of theory. In addition to the chair conformers also the energetically adjacent twist conformers were considered and the positions of the corresponding conformational equilibria estimated. On the basis of the global energy minima of conformers, participating in the conformational equilibria, the 1J(C,Hax,equ) coupling constants were calculated using the GIAO method and compared with the experimental values obtained from C-13, H-1 coupled C-13 NMR spectra. The Perlin effect, the influence of the solvent and the suitability of this NMR parameter for assigning the conformational equilibria present are critically discussed. (c) 2005 Elsevier Ltd. All rights reserved.

引用

页码：7349 / 7358

页数：10

共 59 条

[1]

*ADF, 200301 ADF SCM VRIJ

[2] Stereoelectronic interactions in cyclohexane, 1,3-dioxane, 1,3-oxathiane, and 1,3-dithiane:: W-effect, σC-X ⇆ σ*C-H interactions, anomeric effect -: What is really important? [J].