title: Conformation of acetate derivatives of sugars and other cyclic alcohols. Crystal structures, NMR studies, and molecular mechanics calculations of acetates. When is the exocyclic C-O bond eclipsed?
abstract: [reaction: see text] A study of published crystal structures (of O-acetylated sugars for the most part) suggests that the exocyclic C-O bond in acetate esters of cyclic alcohols intrinsically prefers a staggered conformation, although the eclipsed conformation is only slightly less stable. When the acetate is flanked by two equatorial substituents the preferred conformation is close to eclipsed. Over 1500 C-OAc bonds have been analyzed. Diagnostic NMR criteria for torsion angles and MM3 calculations are reported and confirm these conclusions.
authors.affiliation: Chemistry Department, University College London, Gower Street, London WC1E 6BT, UK. uccajgo@ccrc.uga.edu
authors.forename: Jorge
authors.initials: J
authors.lastname: González-Outeiriño
authors.forename: Rima
authors.initials: R
authors.lastname: Nasser
authors.forename: J Edgar
authors.initials: JE
authors.lastname: Anderson