title: De novo asymmetric syntheses of D- and L-talose via an iterative dihydroxylation of dienoates.
abstract: [reaction: see text] A short and highly efficient route to D- and L-talo-gamma-lactones has been developed. The key transformation was the sequential osmium-catalyzed bis-dihydroxylation reaction of substituted 2,4-dienoates. When the first dihydroxylation reaction is performed on (2Z,4E)-dienoates with use of the Sharpless AD-mix procedure, a regio- and enantioselective dihydroxylation resulted along with an in situ lactonization. A subsequent dihydroxylation, using OsO4/NMO in MeOH conditions, resulted in an exceedingly diastereo- and enantioselective synthesis of talo-gamma-lactone.
authors.affiliation: Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, USA.
authors.forename: Md Moinuddin
authors.initials: MM
authors.lastname: Ahmed
authors.forename: George A
authors.initials: GA
authors.lastname: O'Doherty
mesh_terms: D002087:Butyrates / Q000737:chemistry; D002241:Carbohydrates / Q000138:chemical synthesis; D006900:Hydroxylation; D007783:Lactones / Q000138:chemical synthesis*; D009574:Nitro Compounds / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: C508635:6-(nitrooxy)hexyl-(2z)-4-(acetyloxy)-3-(4-(methylsulfonyl)phenyl)-2-phenylbut-2-enoate; D002087:Butyrates; D002241:Carbohydrates; C510913:L-talo-gamma-lactone; D007783:Lactones; D009574:Nitro Compounds