Showing papers on "Glucal published in 1987"
TL;DR: In this article, Butyldimethylsilyl chloride is used for direct 3,6-di-O -protection of D-glucal and D-galactal.
35 citations
01 Jan 1987-International Journal of Radiation Applications and Instrumentation. Part A. Applied Radiation and Isotopes
TL;DR: In this paper, the presence of 2-deoxy-2-18-tri-O -acetyl-d-glucal (TAG) with [ 18 F]acetyl hypofluorite (FDM) was quantified by radio HPLC analysis of reacetylated [18 F]FDG.
12 citations
TL;DR: In this article, a new mechanism is proposed that invokes stabilization of 3-oxa-allylic cation species by the central Mo(VI) atom, which is a common mechanism for all of the above transformations.
Abstract: Heptamolybdate-ion(HM)-catalyzed C(2) epimerization of D-glucose and racemization of D-glyceraldehyde proceed with comparable rates and activation parameters; HM catalyzes the isomerization of glucal and galactal triacetates as well. For all of the above transformations, a common, new mechanism is proposed that invokes stabilization of 3-oxa-allylic cation species by the central Mo(VI) atom.
11 citations
TL;DR: In this article, maleic anhydride (MAnh) was used to copolymerize tri-O-acetyl, tri-o-benzyl-, tri-obenezyl-D-glucal derivatives with MAnh to afford novel vinyl copolymers containing sugar residues in the main chain.
Abstract: Tri-O-acetyl-, tri-O-benzyl-, tri-O-methyl-D-glucal were copolymerized with maleic anhydride (MAnh) to afford novel vinyl copolymers containing sugar residues in the main chain. Tri-O-benzyl-D-glucal (TBG) showed higher copolymerization reactivity with MAnh than the other glucal derivatives. The copolymerization of TBG and MAnh was carried out at various monomer feed ratios to give the copolymers always rich in MAnh units. Both the complex and penultimate models could explain the compositional data, but the analysis of the copolymerization rate suggested the participation of the CT complex in the propagation.
3 citations
TL;DR: In contrast with the precedent reports described in peracetyl and perbenzyl-D-glucal, chlorination of 3-O-acetyl- and 3-deoxy-4-6-Obenzylonidene-Dglucalin in carbon tetrachloride predominantly occurred from the β-side to give the β -D-manno and β-Darabino adducts, respectively.
Abstract: In contrast with the precedent reports described in peracetyl-and perbenzyl-D-glucal, chlorination of 3-O-acetyl- and 3-deoxy-4,6-O-benzylidene-D-glucal in carbon tetrachloride predominantly occurred from the β-side to give the β-D-manno and β-D-arabino adducts, respectively.
2 citations
TL;DR: A stable furanoid glucal, 3-O-benzyl-1,2-dideoxy-5,6-Oisopropylidene-d-arabino-hex-1-enofuranose (BIF) was synthesized, and the equilibrium association constant K for the charge-transfer complex formation with maleic anhydride in CDCl3 at 25°C was 0.131 mol−1 as determined by 13C NMR as discussed by the authors.
Abstract: A stable furanoid glucal, 3-O-benzyl-1,2-dideoxy-5,6-O-isopropylidene-d-arabino-hex-1-enofuranose (BIF) was synthesized, and the equilibrium association constant K for the charge-transfer complex formation with maleic anhydride in CDCl3 at 25°C was 0.131 mol−1 as determined by 13C NMR. BIF copolymerized with maleic anhydride almost alternatingly, AIBN being used as the initiator. Other electron accepting monomers such as N-phenylmaleimide and acrylonitrile also copolymerized with BIF. Terpolymerization of BIF-maleic anhydride-acrylonitrile gave the copolymer containing BIF residues.
1 citations
TL;DR: In this paper, a new mechanism is proposed that invokes stabilization of 3-oxa-allylic cation species by the central Mo(VI) atom, which is a common mechanism for all of the above transformations.
Abstract: Heptamolybdate-ion(HM)-catalyzed C(2) epimerization of D-glucose and racemization of D-glyceraldehyde proceed with comparable rates and activation parameters; HM catalyzes the isomerization of glucal and galactal triacetates as well. For all of the above transformations, a common, new mechanism is proposed that invokes stabilization of 3-oxa-allylic cation species by the central Mo(VI) atom.
TL;DR: In this article, 2-deoxy-2-fluoro-d-glucose and 2-Deoxy-1,5-anhydro-d -hex-1-enitol were fluorinated in water and organic solvent-water with molecular fluorine and, for 18 F-labelled compounds, with [ 18 F]fluorine.
Abstract: 1,5-Anhydro-2-deoxy- d - arabino - ( d -glucal), 1,5-anhydro-2-deoxy- d - lyxo - ( d -galactal), and 3,4,6-tri- O -acetyl-1,5-anhydro-2-deoxy- d - lyxo -hex-1-enitol (3,4,6-tri- O -acetyl- d -galactal) ( 3 ) were fluorinated in water and organic solvent-water with molecular fluorine and, for 18 F-labelled compounds, with [ 18 F]fluorine. Chemical yields of 40 and 10% were obtained for 2-deoxy-2-fluoro- d -glucose and 2-deoxy-2-fluoro- d -mannose, respectively, and 35 and 5% for 2-deoxy-2-fluoro- d -galactose ( 12 ) and 2-deoxy-2-fluoro- d -talose ( 13 ), respectively. In the fluorination of 3 , the chemical yields of 12 and 13 were 38 and 6%, respectively. An l.c. separation of 2-deoxy-2-fluoro- d -hexoses is described.
TL;DR: In contrast with the precedent reports described in peracetyl and perbenzyl-D-glucal, chlorination of 3-O-acetyl- and 3-deoxy-4-6-Obenzylonidene-Dglucalin in carbon tetrachloride predominantly occurred from the β-side to give the β -D-manno and β-Darabino adducts, respectively.
Abstract: In contrast with the precedent reports described in peracetyl-and perbenzyl-D-glucal, chlorination of 3-O-acetyl- and 3-deoxy-4,6-O-benzylidene-D-glucal in carbon tetrachloride predominantly occurred from the β-side to give the β-D-manno and β-D-arabino adducts, respectively.