title: Extension of the Nef reaction to C-glycosylnitromethanes.
abstract: Acid-catalysed methanolysis of 3,4,5,6-tetra-O-acetyl-1,2-dideoxy-l-arabino-hex-1-enitol proceeds via a cascade set of consecutive reactions resulting in its regiospecific conversion to a mixture of alpha- and beta-C-L-arabinofuranosylmethanal dimethyl acetals and a mixed internal methyl acetal. Structures of the final products of the overall process provide unique evidence that a kinetically controlled, five-membered-ring closure precedes a six-membered-ring closure in reversible systems capable of giving both five-membered and six-membered all-sp3-atom rings. Determination of the reaction intermediate enabled extension of the Nef reaction to C-glycosylnitromethanes. Protonated aci-nitro forms of C-glycosylnitromethanes that are resistant to the Nef reaction in aqueous acidic media undergo a modified Nef reaction in acidified methanol, and the corresponding C-glycosylmethanal dimethyl acetals with alpha-L-arabinopyranosyl, beta-D-glucopyranosyl, beta-D-galactopyranosyl, beta-D-mannopyranosyl and beta-L-rhamnopyranosyl configurations were obtained in moderate yields.
authors.affiliation: Institute of Chemistry, Slovak Academy of Sciences, SK-84538 Bratislava, Slovakia.
authors.forename: Mária
authors.initials: M
authors.lastname: Petrusová
authors.forename: Michal
authors.initials: M
authors.lastname: Vojtech
authors.forename: Bozena
authors.initials: B
authors.lastname: Pribulová
authors.forename: Erika
authors.initials: E
authors.lastname: Lattová
authors.forename: Mária
authors.initials: M
authors.lastname: Matulová
authors.forename: Monika
authors.initials: M
authors.lastname: Poláková
authors.forename: James N
authors.initials: JN
authors.lastname: BeMiller
authors.forename: Vladimír
authors.initials: V
authors.lastname: Kren
authors.forename: Ladislav
authors.initials: L
authors.lastname: Petrus
mesh_terms: D007700:Kinetics; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry; D008956:Models, Chemical; D015394:Molecular Structure; D009005:Monosaccharides / Q000138:chemical synthesis* / Q000737:chemistry; D009595:Nitroparaffins / Q000737:chemistry*
chemical_list: D009005:Monosaccharides; D009595:Nitroparaffins; D008697:Methane; C008640:nitromethane