- Glycosidase inhibitors: Synthesis of enantiomerically pure aza-sugars from Schiff base amino esters via tandem reduction-alkenylation and osmylation
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Nitrogen-in-the-ring 'aza-sugars' have been synthesized in enantiomerically pure form from the amino acid L-alanine in excellent overall yield. The O'Donnell's Schiff base of L-alanine methyl ester 9a was converted to aza-sugar L-fuco-1-deoxy-nojirimycin, 18, and to the epimer L-gulo-1- deoxy-nojirimycin, 20, in eight steps. The overall yields were 20 and 29%, respectively. The methodology for the efficient generation of silyl- and benzyl-protected (E)-3-lithio-2-propen-1-ols, and the use of these alkenyllithiums with iBu5Al2H as nucleophiles in the threo-selective tandem reduction-alkenylation of the Schiff base esters is described. Osmium- catalyzed cis-oxygenation of the resulting olefin products was selective for the galacto (fuco) amino polyols in all cases for the acyclic olefins, and was gulo-selective for the cyclic D-4,5-dihydropyridine pivalate, 17c. TEMPO- NaOCl was selective for oxidation of the primary position of the acyclic Schiff bases, and allowed for minimal protection/deprotection of the intermediates. The resulting N-benzhydryl heterocycles were easily deprotected with H2-Pd at atmospheric pressure.
- Polt, Robin,Sames, Dalibor,Chruma, Jason
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p. 6147 - 6158
(2007/10/03)
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- Method of inhibiting virus
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A group of five- and six-membered heterocyclic compounds having a nitrogen in the ring and 2 to 3 hydroxyl substituents on the ring are effective inhibitory agents of human immunodeficiency virus.
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- Monosaccharides Containing Nitrogen in the Ring, XXXIX. - Synthesis of Analogues of 1,5-Dideoxy-1,5-imino-L-fucitol, Inhibitors of &α-L-Fucosidase
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Variation of the side chain in the 1,3-dithiane derivative 1 of D-galactose leads to a series of analogues of 1,5-dideoxy-1,5-imino-L-fucitol (deoxyfuconojirimycin) (33), which are potent inhibitors of α-L-fucosidase.Cleavage of the dithioacetal in 5 foll
- Paulsen, Hans,Matzke, Michael,Orthen, Bruno,Nuck, Rolf,Reutter, Werner
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p. 953 - 963
(2007/10/02)
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