title: Asymmetric histidine-catalyzed cross-aldol reactions of enolizable aldehydes: access to defined configured quaternary stereogenic centers.
abstract: A histidine-catalyzed asymmetric direct cross-aldol reaction of enolizable aldehydes is described. In contrast to proline, histidine is able to clearly differentiate the reactivity of various aldehydes. In addition, this approach provides access to syn-configured beta-hydroxyaldehydes. Thus, by application of this new methodology, defined-configuration quaternary stereocenters can be constructed with ease. The utility of this method is demonstrated in several total syntheses of branched-chain carbohydrates.
authors.affiliation: Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor Str. 2, 12489 Berlin, Germany.
authors.forename: Morris
authors.initials: M
authors.lastname: Markert
authors.forename: Ulf
authors.initials: U
authors.lastname: Scheffler
authors.forename: Rainer
authors.initials: R
authors.lastname: Mahrwald
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives / Q000138:chemical synthesis; D000447:Aldehydes / Q000737:chemistry*; D002384:Catalysis; D006639:Histidine / Q000737:chemistry*; D010429:Pentoses / Q000138:chemical synthesis; D013237:Stereoisomerism
chemical_list: D000447:Aldehydes; D010429:Pentoses; D006639:Histidine; C043333:lyxose; C005412:pantolactone; C116609:3-hydroxybutanal; D015107:4-Butyrolactone