Full acetals of β-d-glycopyranosylnitromethanes and a 1,2-dideoxy-1-nitroalk-1-enitol derived from common hexoses
作者:Duy-Phong Pham-Huu、Mária Petrušová、James N. BeMiller、Peter Köll、Jüngen Kopf、Ladislav Petruš
DOI:10.1016/s0008-6215(97)00203-6
日期:1998.1
Mono-O-benzylidenation of the starting compounds with benzaldehydedimethylacetal followed by O-isopropylidenation led to 4,6-O-benzylidene-2,3-O-isopropylidene acetals having better solubilities in non-polar solvents than the di-O-isopropylidene acetals. Di-O-benzylidenation of β- d -mannopyranosylnitromethane gave both (endo-2,3):4,6- and (exo-2,3):4,6-di-O-benzylidene acetals. Transacetalation of 1-deoxy-1-nitro-
Stereochemische aspekte in zusammenhang mit der synthese von 2,6-anhydro-1-desoxy-1-nitroalditolen
作者:Armin Förtsch、Heide Kogelberg、Peter Köll
DOI:10.1016/0008-6215(87)80143-x
日期:1987.7
Abstract 2,6-Anhydro-1-deoxy-1-nitroalditols were prepared in good yields by known procedures via addition of nitromethane to d -glucose, d -mannose, d -galactose, d -xylose, d -lyxose and l -arabinose, followed by a cyclization step in boiling water. In the case of d -ribose, a mixture of pyranoid and furanoid anhydroalditols was isolated by different methods in relatively poor yields, at variance
Syntheses of 2,6-anhydroaldonic acids from the corresponding anhydrodeoxynitroalditols (glycopyranosylnitromethanes) and their conversion into methyl esters, amides, and alditols
作者:Manfred Dromowicz、Peter Köll
DOI:10.1016/s0008-6215(98)00195-5
日期:1998.9
Abstract 2,6-Anhydroaldonic acids were obtained by oxidation of the corresponding anhydrodeoxynitroalditols (glycopyranosylnitromethanes) with hydrogen peroxide in alkaline solution. Purification was achieved via the methyl anhydroaldonates. The syntheses of five 2,6-anhydrohexonic and eight 2,6-anhydroheptonic acids were accomplished in yields of 44–81%. All corresponding unprotected and acetylated
3,4-Dipyranosyl-1,2,5-oxadiazole 2-oxides: synthesis and X-ray structure
作者:Kenneth W.J Baker、Andrew R March、Simon Parsons、R.Michael Paton、Gavin W Stewart
DOI:10.1016/s0040-4020(02)01023-2
日期:2002.10
has been synthesised from d-mannose by a route involving as the key step dimerisation of mannopyranosyl nitrile oxide 2. Three methods were used for the generation of the nitrile oxide: isocyanate-mediated dehydration of nitromethylmannose derivative 4, treatment of aldoxime 5 with aq. hypochlorite, and base-induced dehydrochlorination of hydroximoyl chloride 6. d-Gluco, d-galacto, d-xylo, and l-fucopyranosyl
treatment then provides 76% of D-galactofuranosyl nitromethanes and finally results in the equilibrium of 77% of beta-D-galactopyranosyl nitromethane and 7-9% of three other tautomeric D-galactosyl nitromethanes. Thermal treatment of 7-deoxy-7-nitro-L-glycero-L-galacto-heptitol in boiling water peaks at a 58% content of D-galactofuranosyl nitromethanes and ends in a similar equilibrium mixture of four