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  • 1975-1979  (14)
  • 1978  (14)
  • Organic Chemistry  (7)
  • Inorganic Chemistry  (4)
  • Physics  (3)
  • Nuclear reactions
  • 1
    Electronic Resource
    Electronic Resource
    Phosphorhaltige Kohlenhydrate, XVII: Untersuchung der Hydrierung ungesättigter Glycosylphosphonate. Anomerer Effekt und A-Wert der Dimethylphosphono-Gruppe (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 3325-3335 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Phosphorus-containing Carbohydrates, XVII: Studies on the Hydrogenation of Unsaturated Glycosylphosphonates. Anomeric Effect and A-Value of the Dimethylphosphono GroupBy hydrogenation unsaturated glycosylphosphonates of type 1 give rise to the formation of 2,3-dideoxyglycosylphosphonates 2 and 2,3,4-trideoxyglycosylphosphonates 3. Their product ratio depends on configuration and conformation of the educts 1a-f. 1H and 13H and 13C NMR data permit an assigment of the anomers of the hydrogenated glycosylphosphonates. For the one-bond coupling constant between 13C-1 and 31P the correlation 1JC, Peq 〉 1JC, Pax is valid, which exhibits a difference of 19-23 Hz. The unsaturated glycosylphosphonates show deviations from Hudson's isorotation rule. In dimethyl cis-4-methyl-1-cyclohexanephosphonate (9) the A-value of the dimethylphosphono group has been determined to 8.34 kJ/mol. The ratio of conformers in 3a leads to an anomeric effect of the dimethylphosphono group of 2.33 kJ/mol.
    Notes: Ungesättigte Glycosylphosphonate vom Typ 1 liefern bei der Hydrierung außer 2,3-Didesoxyglycosylphosphonaten 2 auch 2,3,4-Tridesoxyglycosylphosphonate 3. Das Produktverhältnis ist von Konfiguration und Konformation der Ausgangsprodukte 1a-f abhängig. 1H- und 13C-NMR-Daten erlauben eine Anomerenzuordnung der hydrierten Glycosylphosphonate. Für die 13C-31P-Direktkopplung an C-1 gilt 1JC, Peq 〉 1JC, Pax mit einer Differenz von 19-23 Hz. Die ungesättigten Glycosylphosphonate zeigen Abweichungen von der Hudsonschen Regel. Am Dimethyl-cis-4-methyl-1-cyclohexanphosphonat (9) wurde der A-Wert der Dimethylphosphono-Gruppe zu 8.34 kJ/mol bestimmt. Aus der Konformerenverteilung bei 3a ergibt sich der anomere Effekt der Dimethylphosphono-Gruppe zu 2.33 kJ/mol.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781111006
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  • 2
    Electronic Resource
    Electronic Resource
    The Inversion of the Amino Group in Vinylamine, a Flexible Model TreatmentA preliminary account of this work was given at the meeting of the Swiss Chemical Society in Geneva, October 9, 1976. (1978)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 61 (1978), S. 1418-1426 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Flexible model results for the —NH2 inversion in vinylamine are compared with microwave data published by Lovas et al. [3]. The information available on the spacing of inversion levels is found to be sufficient to rule out a planar equilibrium structure. Shifts of rotational constants upon excitation of the inversion are calculated for two predicted paths of motion derived from PRDDO geometry optimization results obtained by MiiIler & Brown [2]. Partial geometry optimization yields a path inconsistent with experiment but the path obtained from complete optimization produces shifts in excellent agreement with the observed shifts. A potential energy function compatible with experimental data on spacing of inversion levels is calculated from the observed inertia defects. The inversion angle at equilibrium is slightly smaller than the angle predicted from PRDDO calculations, and the barrier to inversion, ΔV = 1.08 ± 0.07 kcal/mol, is approximately half the PRDDO value.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19780610426
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  • 3
    Electronic Resource
    Electronic Resource
    Four-center photopolymerization. A heterogeneous topochemical solid-state reaction (1978)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 16 (1978), S. 1365-1379 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The four-center solid-state photopolymerization of distyrylpyrazine (DSP) and of 2,6-naphthalene bis(acrylic acid-2,4-dichloro phenyl ester) (NBA-DCP) was investigated by x-ray and microscopic techniques. In both cases the polymer grows as a separate product phase topotactically well arranged with respect to the monomer matrix. In the case of polymerization of DSP the space group of the monomer (Pbca) is not maintained but the polymer phase has space group P21ca. Nucleation and growth of the polymer phase was observed by light and electron microscopy. Nucleation occurs at defect sites. The polymer grows at different rates in different crystallographic directions which were identified by electron diffraction in the case of DSP. Polymerization thus occurs in the transition region between monomer crystal and product phase and not in the bulk of the crystal so that the four-center-type photopolymerization is best described as a heterogeneous solid-state reaction.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1978.180160803
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  • 4
    Electronic Resource
    Electronic Resource
    Umsetzung des 2-Butinsäuredianions mit Aldehyden; Synthese einiger Naturstoffe mit 5,6-Dihydro-2H-pyran-2-on-Struktur (1978)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1978 (1978), S. 337-344 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reaction of the 2-Butynoic Acid Dianion with Aldehydes; Synthesis of some Natural Products with 5,6-Dihydro-2H-pyran-2-one Structure1)The naturally occurring 5,6-dihydro-2H-pyran-2-ones 6a, 6b and 6e have been synthesised starting from the 2-butynoic acid dianion 1 and the aldehydes 2a  -  c with 5-hydroxy-2-alkynoates 4a  -  c as intermediates.
    Notes: Die natürlich vorkommenden 5,6-Dihydro-2H-pyran-2-onderivate 6a, 6b und 6e werden ausgehend von dem 2-Butinsäuredianion 1 und den Aldehyden 2a  -  c über die 5-Hydroxy-2-alkinsäureester 4a  -  c als Zwischenstufen synthetisiert.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197819780214
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  • 5
    Electronic Resource
    Electronic Resource
    Dihydropyridine, IV. Kondensation von Aldehyden mit EndiaminocarbonylverbindungenTeil eines Vortrages vor der Fachgruppe „Medizinische Chemie“ der GDCh am 29. März 1974 in München. (1978)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1978 (1978), S. 1476-1482 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Dihydropyridines, IV.  -  Condensation of Aldehydes with Enediaminocarbonyl CompoundsReaction of aldehydes 1 with double molar quantities of amidinoacetic esters 5 leads to the 2,6-diaminodihydropyridine-3,5-dicarboxylates 8. 2-Amino-6-dialkylamino-4,5-dihydropyridines 12 are obtained by condensation of 1 with 3-amino-3-dialkylaminoacrylic esters 11. Pyridones 17 with bridgehead nitrogen are formed by condensation of 1 with bridged enediaminocarbonyl compounds 15.
    Notes: Die Kondensation von Aldehyden 1 mit Amidinoessigsäureestern 5 im Molverhältnis 1:2 führt zu 2,6-Diaminodihydropyridin-3,5-dicarbonsäureestern 8. 3-Amino-3-dialkylaminoacrylsäureester 11 liefern mit 1 unter analogen Bedingungen die 2-Amino-6-dialkylamino-4,5-dihydropyridine 12. Dihydropyridone 17 mit Brückenkopf-N-Atom werden durch Kondensation von 1 mit den N,N′-verbrückten Endiaminocarbonsäureestern 15 erhalten.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197819780912
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  • 6
    Electronic Resource
    Electronic Resource
    Ion clustering in a butadiene, styrene, 4-vinylpyridine terpolymer crosslinked by coordination with iron(III) chloride (1978)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 16 (1978), S. 569-581 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A butadiene, styrene, 4-vinylpyridine terpolymer has been crosslinked by coordination of the pyridine groups with iron chloride. The distribution and structure of the iron complexes have been studied. Electron microscopy has given evidence of clustering of the iron complexes. The size distribution of these clusters has been evaluated by small-angle x-ray and neutron scattering. Mössbauer spectroscopy and magnetization measurements have shown the presence of three different kinds of iron complexes: (a) complexes with a speromagnetic structure in the clusters previously found, (b) dimers with antiferromagnetic coupling, and (c) quasi-isolated complexes with weak ferromagnetic coupling. The percentages of these different iron complexes have been measured.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1978.180160401
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  • 7
    Electronic Resource
    Electronic Resource
    On the structure of glassy polymers. VI. Electron microscopy of polycarbonate, poly(ethylene terephthalate), poly(vinyl chloride), and polystyrene (1978)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 16 (1978), S. 2005-2014 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: High-resolution electron microscopy studies have been carried out on four glassy polymers examined in previous small-angle x-ray scattering (SAXS) investigations. The polymers include polycarbonate, poly(ethylene terephthalate), poly(vinyl chloride), and polystyrene. For all four polymers, both bright field and dark-field observations indicate the general absence of microstructural features of a size down to the resolution limit of the electron microscope. Only “pepper and salt” features on a scale ca. 5 Å are seen as characteristic of the structures. These features reflect simple interferences as the resolution limit is approached, and are seen for single crystal and oxide glasses as well as for the polymers. The present results, taken together with structural information from light scattering, SAXS, and small-angle neutron scattering, indicate that glassy polymers should be regarded as having rendom structures. The combined results are inconsistent with heterogeneous microstructures having regions of locally high order present in large volume fractions.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1978.180161110
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  • 8
    Electronic Resource
    Electronic Resource
    Über die Biosynthese der Mutterkornalkaloide, VI. Über den Einbau von [4'-(E)-13C]4-(3-Methyl-2-butenyl)tryptophan in Clavinalkaloide und Lysergsäure (1978)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1978 (1978), S. 813-817 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Incorporation of [4'-(E)-13C]4-(3-Methyl-2-butenyl)tryptophan into Clavine Alkaloids and Lysergic AcidThe 13C-enriched C-atom of the 4'(E)-methyl groups of 4-(3-methyl-2-butenyl)tryptophan (3) appears during the biosynthesis at the C-methyl group of chanoclavine (4) and at C-17 of agroclavine (5), elymoclavien (6) and lysergic acid (7).
    Notes: Das 13C-angereicherte C-Atom der 4'-(E)-Methylgruppe im 4-(3-Methyl-2-butenyl)tryptophan (3) erscheint bei der Biosynthese in der C-Methylgruppe des Chanoclavins (4) und im C-17 von Agroclavin (5), Elymoclavin (6) und Lysergsäure (7).
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197819780516
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  • 9
    Electronic Resource
    Electronic Resource
    Totalsynthese von (±)-2,2-Diethyl-3-methyl- und (±)-2,2-Diethyl-3,6-dimethyl-6-(phenoxyacetamido)penam-3-carbonsäure (1978)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1978 (1978), S. 1982-1989 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of (±)-2,2-Diethyl-3-methyl- and (±)-2,2-Diethyl-3,6-dimethyl-6-(phenoxyacetamido)-penam-3-carboxylic acidThe title compounds 4I and 4k were synthesized as the potassium salts 4I', 4k' starting from benzyl 4-methyl-2-thiazolinecarboxylate (3a).  -  The preparation of several benzyl 2-thiazoline-4-carboxylates (type 3) from thioketones 2 and 2-metalated benzyl 2-isocyanoalkanecarboxylates 1b, d is described.
    Notes: Die im Titel genannten Verbindungen 4I und 4k wurden (als Kaliumsalze 4I' bzw. 4k') ausgehend von 5,5-Diethyl-4-methyl-2-thiazolin-4-carbonsäure-benzylester (3a) dargestellt.  -  An mehreren Beispielen wird die Synthese von 2-Thiazolin-4-carbonsäure-benzylestern (Typ 3) aus Thioketonen 2 und 2-metallierten 2-Isocyanalkansäureestern 1b und d beschrieben.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197819781213
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  • 10
    Electronic Resource
    Electronic Resource
    Malondiamidine, I. (3 + 3)-Kondensationen mit 1,3-DicarbonylverbindungenHerrn Prof. H. Henecka mit besten Wünschen zum 75. Geburtstag gewidmet. (1978)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1978 (1978), S. 1491-1504 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Malondiamidines, I.  -  (3 + 3)-Condensations with 1,3-Dicarbonyl CompoundsMalondiamidines 4, 5, 8a-g, 11 and 14 are prepared from corresponding imidates using the Pinner method. The parent compound 5 undergoes condensation with double molar quantities of 1,3-dicarbonyl compounds yielding 3-(2-pyrimidyl)-2-pyridinamines 16 and 17a-g. Condensation of 1,3-dicarbonyl compounds with N,N′-bridged malondiamidine 11 furnishes 8-(2-imidazolinyl)imidazo[1,2-a]pyridines 19a-d. H/D-exchange phenomena of the 5,7-dimethyl derivative 19a are discussed. Use of 3-keto esters and tricarbonyl compounds in condensation with 11 results in formation of 26, 27 and 28, respectively.
    Notes: Die Malondiamidine 4, 5, 8a-g, 11 und 14 werden aus den korrespondierenden Imidsäureestern nach Pinner hergestellt. Die Stammverbindung 5 kondensiert mit der doppelt molaren Menge von 1,3-Dicarbonylverbindungen zu 3-(2-Pyrimidyl)-2-pyridinaminen 16 und 17a-g. Bei der Kondensation von dem N,N′-verbrückten Malondiamidin 11 mit 1,3-Dicarbonylverbindungen resultieren die 8-(2-Imidazolinyl)imidazo[1,2-a]pyridine 19a-d. Die H/D-Austauschphänomene des 5,7-Dimethylderivates 19a in der 1H-NMR-Spektroskopie werden diskutiert. Der Einsatz von 3-Ketocarbonsäureestern und 1,3,5-Tricarbonylverbindungen in der Kondensation mit 11 führt zu den Tri- bzw. Tetracyclen 26, 27 und 28.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197819780914
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