✦ LIBER ✦
Conformational analysis of cis-3, 5-dioxa-bicyclo[5.4.0]undecane and its 4-substituted derivatives by DNMR, molecular modeling, and GIAO/DFT methods
✍ Scribed by Wojciech Migda; Anna Stankiewicz; Edward Szneler; Lucyna Ulman; Barbara Rys
- Book ID
- 102532171
- Publisher
- John Wiley and Sons
- Year
- 2010
- Tongue
- English
- Weight
- 201 KB
- Volume
- 48
- Category
- Article
- ISSN
- 0749-1581
- DOI
- 10.1002/mrc.2657
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✦ Synopsis
Abstract
Temperature‐dependent ^1^H and ^13^C‐NMR spectra of the title compounds are presented. Coalescence effects are discussed and assigned to dynamic process—the interconversion of bicyclic system. The free energies of activation covered the range 39–52 kJ/mol. The dioxepane ring adopts twist‐chair (TC) conformation. GIAO/DFT calculation of isotropic shieldings for the set of low‐energy conformations showed that only one conformer is present at 298 K in solution that matched well with experimental data. Copyright © 2010 John Wiley & Sons, Ltd.