Halo sugar nucleosides. V. Synthesis of angustmycin A and some base analogues
About: This article is published in Journal of Organic Chemistry.The article was published on 1976-05-14. It has received 86 citations till now.
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TL;DR: In this paper, a microreview of recent syntheses of polyhydroxylated piperidines is presented, focusing on recent synthesises of azasugars and their analogs.
202 citations
TL;DR: In this article, a combination of 11B and 13C NMR spectroscopy with several model compounds has been used to elucidate the nature of the ester formation between borate and D-mannitol, D-glucitol and D -fructose in aqueous solution at pH 6-12 and at 25 °C.
Abstract: A combination of 11B and 13C NMR spectroscopy with several model compounds has been used to elucidate the nature of the ester formation between borate and D-mannitol, D-glucitol, D-fructose and D-glucose in aqueous solution at pH 6-12 and at 25 °C. At high carbohydrate/borate ratios, D-mannitol shows the selective formation of bis(D-mannitol) 3,4:3′4′ -borate, whereas D-glucitol forms a mixture of six different bis(D-glucitol) borate esters involving both 2,3- and 3,4-dihydroxyl moieties. Bis(D-fructose) and bis(D-glucose) borate esters consist of pairs of diastereomers of the 2,3-β-and 1,2-α-furanose moieties, respectively. At low carbohydrate/borate ratios, mono-, di- and, sometimes, tri-borate esters are formed, e.g. mixture of α-D-glucofuranose 1,2:3,5-diborate and α-D-glucofuranose 1,2:5,6-diborate for D-glucose and a mixture of β-D-fructopyranose 1,2:4,5-diborate and β-D-fructopyranose 2,3:4,5-diborate for D-fructose. The overall stability constant for the borate di-esters of D-mannitol, D-glucitol and D-fructose is about two orders of magnitude higher than that of D-glucose.
109 citations
TL;DR: A new facile method for monoacylation of diols has been developed and was successfully applied to a kinetic resolution of racemic 1-phenyl-1,2-ethanediol using a chiral organotin catalyst.
Abstract: A new facile method for monoacylation of diols has been developed. A variety of cyclic and acyclic diols, in particular 1,2-diols, were selectively monobenzoylated in good yields by the reaction with benzoyl chloride in the presence of a catalytic amount of dimethyltin dichloride and inorganic bases such as potassium carbonate. Furthermore, the method was successfully applied to a kinetic resolution of racemic 1-phenyl-1,2-ethanediol using a chiral organotin catalyst. The ee was dependent on the kind of base, water as an additive, and the reaction temperature.
109 citations
TL;DR: In this article, 13C NMR spectroscopy was used to investigate complex formation between p-tolylboronic acid and D-fructose in neutral nonaqueous and alkaline aqueous solutions.
Abstract: Complex formation between p-tolylboronic acid and D-fructose was investigated by 13C NMR spectroscopy both in neutral nonaqueous and alkaline aqueous solutions to evaluate the possibilities of boronic acid based fructose sensors. Under both conditions a mixture of complexes was observed. The structures of the complexes in solution were assigned on the basis of 1JCC coupling constants which provided the information of the binding sites for the formed cyclic boronic esters. In alkaline aqueous solution seven different complexes were observed. At a 1:1 boronic acid: fructose ratio the major complex (82%) was β-D-fructofuranose 2,3,6-tri-O-(p-tolylorthoboronate)1. The minor complex was β-D-fructofuranose 2,3-(p-tolylhydroxyboronate) present in two diastereomeric forms 2a and 2b. At higher boronic acid:fructose ratios four additional complexes were observed namely the four possible diastereomeric forms of β-D-fructopyranose 2,3:4,5-bis(p-tolylhydroxyboronate) 3a–d. Under nonaqueous conditions signals arising from 13 different compounds were observed. Five of these complexes were structurally assigned. At a 1:1 boronic acid : fructose ratio the major complex was β-D-fructofuranose 2,3(p-tolylboronate) 5 present in 46%. At a ratio of 4:1 the major species was β-D-fructopyranose 2,3:4,5-bis(p-tolylboronate) 7 present in 67%. Two additional monoesterified pyranoses and one furanose were observed. They were assigned to the β-D-fructopyranose 1,2-(p-tolylboronate) 8, the α-D-fructopyranose 1,3-(ptolylboronate) 9 and the β-D-fructofuranose 1,3-(p-tolylboronate) 6. It is concluded that results of earlier studies on binding constants bear no relation to the actual formed complexes.
108 citations
TL;DR: In this article, a facile synthetic route for the large-scale preparation of a herbicidal natural product, (+)-hydantocidin, was described, which was stereospecifically converted to azidoamide 14 by N -glycosidation (TMSN 3 /TMSOTf), oxidation and amination.
107 citations