Format

Send to

Choose Destination
See comment in PubMed Commons below
J Am Chem Soc. 2008 May 21;130(20):6345-7. doi: 10.1021/ja077633z. Epub 2008 Apr 29.

Pathways and populations: stereoelectronic insights into the exocyclic torsion of 5-(hydroxymethyl)tetrahydropyran.

Author information

  • 1Laboratory of Computational Biology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, USA. hlwood@nih.gov

Abstract

High level ab initio computations in vacuum and with the IEFPCM implicit solvent model are carried out on 5-(hydroxymethyl)tetrahydropyran to investigate the effects of water on the exocyclic torsional surface. Rotamer populations evaluated from the omega(C-C-C-O), theta(C-C-C-O) solvent surface agree almost quantitatively with experimental values for the closely related methyl 4-deoxy-alpha-D-xylohexopyranoside. Potentials of mean force obtained from the two surfaces show substantial solvent stabilization of the TG (omega = 180 +/- 60 degrees) rotamer and the barriers at omega= 120 and 240 degrees but solvent destabilization at the cis barrier (omega = 0 degrees). Natural bond orbital analyses indicate that energetics of these effects are largely explained by overstabilization of the vacuum GT (omega= 60 +/- 60 degrees) and GG (omega = 300 +/- 60 degrees) rotamers. Solvent stabilization of theta conformations provides entropic stabilization.

[PubMed - indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for American Chemical Society Icon for PubMed Central
    Loading ...
    Write to the Help Desk