title: Bis(oxazolines) based on glycopyranosides - steric, configurational and conformational influences on stereoselectivity.
abstract: In previous studies we found that the asymmetric induction of bis(oxazolines) based on D-glucosamine strongly depended on the steric demand of the 3-O-substituents. To further probe the impact of the 3-position of the pyranose scaffold, we prepared 3-epimerised and 3-defunctionalised versions of these ligands as well as a 3-O-formyl derivative. Application of these new ligands in asymmetric cyclopropanation revealed strong steric and configurational effects of position 3 on asymmetric induction, further dramatic effects of the pyranose conformation were also observed.
authors.affiliation: Institute of Organic Chemistry, Gottfried-Wilhelm-Leibniz University of Hannover, Schneiderberg 1B, D-30167 Hannover, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Minuth
authors.forename: Mike M K
authors.initials: MM
authors.lastname: Boysen