Conformational analysis of perezone and dihydroperezone using vibrational circular dichroism |
| |
| Institution: | 1. Departamento de Química Orgánica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Prolongación de Carpio y Plan de Ayala, Col. Santo Tomás, México DF 11340, Mexico;2. Departamento de Química, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Apartado 14-740, México DF, 07000 Mexico;1. College of Chemistry and Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, Xiangtan University, Xiangtan 411105, China;2. CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China;1. Department of Chemistry, Tamkang University, Tamsui, New Taipei City 251, Taiwan;2. General Education Center, Saint John’s University, Tamsui, New Taipei City 251, Taiwan;1. Department of Chemistry, Yasouj University, Yasouj 7591874831, Iran;2. Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada;1. Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran;2. Institute of Biochemistry and Biophysics, University of Tehran, Tehran 13145-1384, Iran;3. Department of Chemistry, Tulane University, New Orleans, LA 70118, USA |
| |
| Abstract: | The vibrational circular dichroism (VCD) spectra of perezone and dihydroperezone measured from CDCl3 solutions were quite similar, suggesting analogous conformations for both molecules. Their absolute configurations were confirmed by comparison of the experimental VCD spectrum of each compound with curves generated from theoretical calculations using density functional theory (DFT) at the B3LYP/DGDZVP level of theory taking into account their conformational mobility. Conformational analysis of the 8-(R) enantiomer showed 19 low energy conformers in a 2.4 kcal/mol energy range, while for 8-(R), with the saturated side alkyl chain, 34 conformers were considered in the first 2 kcal/mol. Initial analyses were carried out using a Monte Carlo searching with the MMFF94 molecular mechanics force field, all MMFF94 conformers were geometrically optimized using DFT at the B3LYP/6-31G(d) level of theory, followed by reoptimization and calculations of their vibrational frequencies at the B3LYP/DGDZVP level. Good agreement between the theoretical 8-(R) enantiomers and experimental VCD curves were observed for both. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
