title: Regio- and stereoselective cyclizations of dianhydro sugar alcohols catalyzed by a chiral (salen)Co(III) complex.
abstract: The (salen)Co(III)OAc ((R,R)-1 and (S,S)-1) catalyzed cyclizations of the chiral dianhydro sugars, 1,2:5,6-dianhydro-3,4-di-O-methyl-D-glucitol (2), 1,2:5,6-dianhydro-3,4-di-O-methyl-D-mannitol (3), 1,2:5,6-dianhydro-3,4-di-O-methyl-L-iditol (4), and 1,2:4,5-dianhydro-3-O-methyl-L-arabinitol (5), is a facile method for the synthesis of anhydroalditol alcohols. Cyclization of 2 using (R,R)-1 and (S,S)-1 proceeded diastereoselectively to form 2,5-anhydro-3,4-di-O-methyl-D-mannitol (6) and 2,5-anhydro-3,4-di-O-methyl-L-iditol (7), respectively. The cyclization of 3 and 5 is a novel method for obtaining 1,6-anhydro-3,4-di-O-methyl-D-mannitol (11) and a stereoselective route to 1,5-anhydro-3-O-methyl-L-arabinitol (13). It is proposed that the reaction occurs via endo-selective cyclization of an epoxy alcohol produced by the endo-selective ring-opening of one of the two epoxide moieties in the starting material.
authors.affiliation: Division of Biotechnology and Macromolecular Chemistry, Graduate School of Engineering, Hokkaido University, Sapporo 060-8628, Japan.
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Satoh
authors.forename: Tomoko
authors.initials: T
authors.lastname: Imai
authors.forename: Satoshi
authors.initials: S
authors.lastname: Umeda
authors.forename: Katsuyuki
authors.initials: K
authors.lastname: Tsuda
authors.forename: Hisaho
authors.initials: H
authors.lastname: Hashimoto
authors.forename: Toyoji
authors.initials: T
authors.lastname: Kakuchi
mesh_terms: D002236:Carbohydrate Conformation; D002614:Chelating Agents; D005029:Ethylenediamines; D006601:Hexoses / Q000138:chemical synthesis* / Q000737:chemistry*; D007202:Indicators and Reagents; D007700:Kinetics; D008958:Models, Molecular; D010429:Pentoses / Q000138:chemical synthesis* / Q000737:chemistry*; D013237:Stereoisomerism; D013402:Sugar Alcohols / Q000138:chemical synthesis* / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D002614:Chelating Agents; D005029:Ethylenediamines; D006601:Hexoses; D007202:Indicators and Reagents; D010429:Pentoses; D013402:Sugar Alcohols; C011452:disalicylaldehyde ethylenediamine