The conformational properties (C-4(1), C-1(4), and skew ring structures, side chain torsion) of methyl 2,4-(1) and 3,4-O-diacetyl (2) as well as 2,4-(3) and 3,4-O-dibenzoyl (4)-SS-D-xylopyranoside are calculated by dispersion-corrected density functional theory (B3LYP-D3) and LPNO-CEPA/1-def2-TZVPP. Derivatives with acyl groups in positions 2 and 4 (1 and 3) prefer the 1C4 chair conformation of the pyranose chair; 3,4-di-O-acyl compounds 2 and 4 show nearly equal or even dominating amounts of the C-4(1) chair. Intramolecular hydrogen bonding of the type O3-H center dot center dot O1 (1 and 3) and O2-H center dot center dot center dot O4 are characteristic for the lowest energy conformations of 1C4 chairs. With increasing solvent polarity a shift towards 4C1 chair structures is calculated. B3LYP-D3 conformer populations show fairly good agreement with CEPA/1 results (R-2 = 0.992).
Keywords:
Density functional / Dispersion correction / LPNO-CEPA/1 / Ring conformation / Substituent and solvent effect
Source:
Computational and Theoretical Chemistry, 2015, 1051, 104-109
TY - JOUR
AU - Vitnik, Željko
AU - Fabian, Walter M F
PY - 2015
UR - https://cer.ihtm.bg.ac.rs/handle/123456789/1746
AB - The conformational properties (C-4(1), C-1(4), and skew ring structures, side chain torsion) of methyl 2,4-(1) and 3,4-O-diacetyl (2) as well as 2,4-(3) and 3,4-O-dibenzoyl (4)-SS-D-xylopyranoside are calculated by dispersion-corrected density functional theory (B3LYP-D3) and LPNO-CEPA/1-def2-TZVPP. Derivatives with acyl groups in positions 2 and 4 (1 and 3) prefer the 1C4 chair conformation of the pyranose chair; 3,4-di-O-acyl compounds 2 and 4 show nearly equal or even dominating amounts of the C-4(1) chair. Intramolecular hydrogen bonding of the type O3-H center dot center dot O1 (1 and 3) and O2-H center dot center dot center dot O4 are characteristic for the lowest energy conformations of 1C4 chairs. With increasing solvent polarity a shift towards 4C1 chair structures is calculated. B3LYP-D3 conformer populations show fairly good agreement with CEPA/1 results (R-2 = 0.992).
PB - Elsevier
T2 - Computational and Theoretical Chemistry
T1 - Ring- and side-group conformational properties of di-O-acylated xylopyranosides: A computational study
VL - 1051
SP - 104
EP - 109
DO - 10.1016/j.comptc.2014.11.004
ER -
@article{
author = "Vitnik, Željko and Fabian, Walter M F",
year = "2015",
abstract = "The conformational properties (C-4(1), C-1(4), and skew ring structures, side chain torsion) of methyl 2,4-(1) and 3,4-O-diacetyl (2) as well as 2,4-(3) and 3,4-O-dibenzoyl (4)-SS-D-xylopyranoside are calculated by dispersion-corrected density functional theory (B3LYP-D3) and LPNO-CEPA/1-def2-TZVPP. Derivatives with acyl groups in positions 2 and 4 (1 and 3) prefer the 1C4 chair conformation of the pyranose chair; 3,4-di-O-acyl compounds 2 and 4 show nearly equal or even dominating amounts of the C-4(1) chair. Intramolecular hydrogen bonding of the type O3-H center dot center dot O1 (1 and 3) and O2-H center dot center dot center dot O4 are characteristic for the lowest energy conformations of 1C4 chairs. With increasing solvent polarity a shift towards 4C1 chair structures is calculated. B3LYP-D3 conformer populations show fairly good agreement with CEPA/1 results (R-2 = 0.992).",
publisher = "Elsevier",
journal = "Computational and Theoretical Chemistry",
title = "Ring- and side-group conformational properties of di-O-acylated xylopyranosides: A computational study",
volume = "1051",
pages = "104-109",
doi = "10.1016/j.comptc.2014.11.004"
}
Vitnik, Ž.,& Fabian, W. M. F.. (2015). Ring- and side-group conformational properties of di-O-acylated xylopyranosides: A computational study. in Computational and Theoretical Chemistry
Elsevier., 1051, 104-109.
https://doi.org/10.1016/j.comptc.2014.11.004
Vitnik Ž, Fabian WMF. Ring- and side-group conformational properties of di-O-acylated xylopyranosides: A computational study. in Computational and Theoretical Chemistry. 2015;1051:104-109.
doi:10.1016/j.comptc.2014.11.004 .
Vitnik, Željko, Fabian, Walter M F, "Ring- and side-group conformational properties of di-O-acylated xylopyranosides: A computational study" in Computational and Theoretical Chemistry, 1051 (2015):104-109,
https://doi.org/10.1016/j.comptc.2014.11.004 . .
