Showing papers on "Glucal published in 1986"
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.
25 citations
TL;DR: A chiral synthesis of the B-C ring system of trichothecenes from tri-O-acetyl-D-glucal by using a photochemical cycloaddition of acetylene to the unsaturated ketone 7, followed by acid-catalyzed rearrangement is described in this article.
19 citations
18 citations
TL;DR: The ratio of 2 to 3 depends largely on the polarity of the solvent rather than on the size of the substituents on the hydroxyl groups of glucal as mentioned in this paper.
11 citations
TL;DR: In this paper, the authors investigated the rearrangement of n-glutal triacetate and pseudo-n-glucal tracetate into (2R,3R)-2-acetoxymethyl-3-acetoxy-tetrahydropyran (4) and showed that hydrogenation of both isomers proceeds through the same intermediate 4,6-di-O-acetyl-l,2,3-trideoxy-nerythro-hex-J-enitol (3) which was fully characterised from
Abstract: Hydrogenation of n-glutal triacetate (1) and pseudo-n-glucal triacetate (2) into (2R,3R)-2-acetoxymethyl-3-acetoxy-tetrahydropyran (4) and the rearrangement of 1 into 2 were investigated. On. hydrogenation, at high catalyst-to-substrate ratio and in the presence of a great excess of diethylamine, compound 1 afforded diacetate 4 in a mixture with triacetate 6, while 2 was quantitatively converted into 4 under standard catalyst-to-substrate (1 :80) ratio. It was established that hydrogenation of both isomers proceeds through the same intermediate 4,6-di-O-acetyl-l,2,3-trideoxy-n-erythro-hex-J-enitol (3) which was fully characterised from its lH_ and 13C-NMRspectra. When hydrogenation of 2 was performed with platinum on carbon in acetonitrile, compound 3 was isolated in 83010yield. The thermal and Lewis acid catalysed rearrangement of 1 into 2 was examined; only zinc(II) chloride in acetic anhydride gave preparatively acceptable yields (60-70010) of 2. It was demonstrated that with Zn(II) or Mo(VI) ions in AC20 an 1 =:; 2 equilibrium in favour of 2 was attained.
4 citations
TL;DR: In this article, a new rapid synthesis of [82Br]-2-deoxy-2-bromo-D-mannose and [82br]-2deoxy -2-boox-2bromobromo -D-glucose is described.
Abstract: A new rapid synthesis of [82Br]-2-deoxy-2-bromo-D-mannose and [82Br]-2-deoxy-2-bromo-D-glucose is described. Reaction of 82Br2 with D-glucal in CHCl3, followed by treatment with 1 N HCl gave [82Br]-2-deoxy-2-bromo-D-mannose and [82Br]-2-deoxy-2-bromo-D-glucose in the yield of 61.1 % and 27.7 %, respectively. The synthesis time was 20 min. The radiochemical purity of [82Br]-2-deoxy-2-bromo-D-mannose and [82Br]-2-deoxy-2-bromo-D-glucose was greater than 95 %. The radiochemical yield of [82Br]-2-deoxy-2-bromo-D-mannose and [82 Br]-2-deoxy-2-bromo-D-glucose was 14.3 % and 31.6 %, respectively. D-Glucal was shown to be a useful precursor to allow rapid production of usable amounts of glucose analogs such as [75Br]-2-deoxy-2-bromo-D-mannose and [75Br]-2-deoxy-2-bromo-D-glucose.
3 citations