ISSN:
0018-019X
Schlagwort(e):
Chemistry
;
Organic Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
Preparation of Unprotected and Partially Protected 1-Deoxy-1-nitro-D-aldoses and Some Representative X-Ray Structure AnalysesThe unprotected and partially protected 1-deoxy-1-nitro derivatives of α-and β-D-glucopyranose (see 15 and 14), β-D-mannopyranose (see 16), N-acetyl-β-D-glucosamine (see 17), β-D-galactofuranose (see 19), β-D-ribofuranose (see 20), α-D-arabinofuranose (see 21), 4,6-O-benzylidene-β-D-glucose (see 40), N-acetyl-4,6-O-benzylidene-β-D-glucosamine (see 41), and 4,6-O-benzylidene-β-D-galactose (see 42) were prepared by ozonolysis of the corresponding nitrones which were obtained from the acid-catalyzed reaction of p-nitrobenzaldehyde with the hydroxylamine 4, the unprotected oximes 3 and 5-9 and the 4,6-O-benzylidene oximes 35-37, respectively (Schemes 1-3). The gluco- and manno-nitrones 10 and 12 were isolated, and their ring size and their anomeric and (E/Z) configurations were determined by NMR spectroscopy and by their transformation into their corresponding nitro derivatives. The structure of the deoxynitroaldoses were determined by NMR spectroscopy, polarimetry, and, in the case of 14, 16, and 17, by formation of the 4,6-O-benzylidene (14→40) or 4,6-O-isopropylidene (16→43, 17→23) derivatives (Scheme 3). Acetylation of the nitroglucopyranose 14, the 2-acetamido-nitroglucopyranose 17, and the nitrogalactofuranose 19 gave the crystalline peracetylated nitroaldoses 22, 24, and 45, respectively (Scheme 4, Figs. 1 and 3); acetylation of the nitromannopyranose 16 gave the nitro-arabino-glycal 44 (Scheme 4). The structure of the peracetylated nitroglucopyranose 22, the nitroglucosamine 25, the nitrogalactofuranose 45, and the nitroribofuranose 20 were confirmed by X-ray analysis (Figs. 1 4). In all cases, including the β-D-glucopyranose derivative 22, considerably shortening of the (endocyclic) C(1)-O bond was observed. Base-catalyzed anomerization of the β-D-configurated nitroglucopyranose 14, the nitromannopyranose 16, the benzylidene acetal 40 of nitroglucose, and the 2,3,4,6-tetraacetylated glucosamine derivative 24 gave the corresponding nitro-α-D-aldoses 15, 26, 47, and 25, respectively (Scheme 4).
Zusätzliches Material:
4 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/hlca.19860690526
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