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  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 6 (1972), S. 122-127 
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Isolation, Structure, and Synthesis of 5,6,7,4′-Tetrahydroxy-3′-methoxyflavone (Batatifoline), a new Flavone from Mikania batatifolia D.C.The flavone batatifoline has been isolated from Mikania batatifolia D. C. (Compositae). Its structure has been confirmed as 5,6,7,4′-tetrahydroxy-3′-methoxyflavone (1) by synthesis of the isomers 1 and 5,6,3′,4′-tetrahydroxy-7-methoxyflavone (5, Pedalitine).
    Notes: Aus Mikania batatifolia D. C. (Compositae) wurde das Flavon Batatifolin isoliert und ihm durch Synthese der Isomeren 5.6.7.4′-Tetrahydroxy-3′-methoxy-flavon (1) und 5.6.3′.4′-Tetra-hydroxy-7-methoxy-flavon (5, Pedalitin) die Struktur 1 zugeordnet.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of Glucuronides in the Flavonoid-Series, II. Isolation of Kaempferol-3-β-D-glucuronide from Euphorbia esula L.From the aerial parts of Euphorbia esula L. (Euphorbiaceae) a flavone-glycoside was isolated and identified as 3,5,7,4′-tetrahydroxyflavone(kaempferol)-3-β-D-glucuronide (8). Its structure was confirmed by coupling of 7,4′ -dibenzylkaempferol with methyl(tri-O-acetyl-α-D-glucopyranosyl bromide)-uronate, followed by total acetylation, debenzylation and saponification to 8.
    Notes: Aus den oberirdischen Teilen von Euphorbia esula L. (Euphorbiaceae) wurde ein Flavonglykosid isoliert und als 3.5.7.4′-Tetrahydroxy-flavon(Kämpferol)-3-β-D-glucuronid (8) identifiziert. Seine Struktur wurde durch Kupplung von 7.4′-Dibenzyl-Kämpferol mit α-Acetobromglucuronsäure-methylester, Darstellung des Vollacetats, Entbenzylierung und Verseifung zu 8 bewiesen.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 104 (1971), S. 473-478 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of 7-β-Neohesperidosyl-4′-(β-D-glucopyranosyl)naringenin, a Flavanone Triglycoside from Citrus FruitsThe glycoside 7-β-neohesperidosyl-4′-(β-D-glucopyranosyl)naringenin (3), isolated from the segments of Citrus paradisi Macf, by Mizelle et al., was synthesized by condensation of phloracetophenone 4-β-neohesperidoside (1) with 4-hydroxybenzaldehyde 4-β-D-glucopyranoside (2) and by cyclisation of the resulting chalkone glykoside. Dehydrogenation of the flavanone triglykoside undecaacetate and subsequent saponification leads to the formation of 7-β-neohesperidosyl-4′-(β-D-glucopyranosyl)apigenin (7), the first synthetic apigenin triglycoside.
    Notes: Das von Mizelle und Mitarbb. aus Citrus paradisi Macf. isolierte 7-β-Neohesperidosyl-4′-β-D-glucopyranosyl-naringenin (3) wurde durch Kondensation von Phloracetophenon-4-β-neohesperidosid (1) mit 4-Hydroxy-benzaldehyd-4-β-D-glucopyranosid (2) und Cyclisierung des entstandenen Chalkonglykosids synthetisiert. Durch Dehydrierung des Flavanontriglykosid-undecaacetats (3a) wurde nach Verseifen das 7-β-Neohesperidosyl-4′-β-D-glucopyranosyl-apigenin (7) als erstes synthetisches Apigenintriglykosid dargestellt.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 104 (1971), S. 320-332 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Ionization of Organomagnesium Compounds, IV. Formation of Carbanions from Organomagnesium Compounds by Means of Hexamethyl-phosphortriamideStepwise addition of hexamethylphosphortriamide (HMPT) to the solutions of benzyl-like organomagnesium compounds in diethylether results in drastic changes which can be observed spectroscopically. First, the absorption maxima are shifted to longer wave lengths in an apparently continuous manner, until two equivalents of the strongly donating cosolvent have been added. Further addition of HMPT leads to ionization of the C—Mg-bonds. This can be seen from the development of new bands characteristic of the carbanions, as represented by the alkali metal derivatives.
    Notes: Der Zusatz von Hexamethylphosphorsäuretriamid (HMPT) zu den ätherischen Lösungen von benzylartigen Organomagnesium-Verbindungen führt zu drastischen, spektral beobachtbaren Veränderungen. Zunächst tritt eine scheinbar kontinuierliche Verschiebung der Absorptionsmaxima nach längeren Wellen ein, bis zwei Äquivalente des starken Donor-Solvens zugesetzt sind. Weitere Zugabe von HMPT führt zur Ionisation der C—Mg-Bindungen und Freisetzung der betreffenden Carbanionen, die sich durch das Aufkommen der (von den Alkalimetall-Verbindungen bekannten) Carbanion-Banden zu erkennen gibt.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of Glucuronides in the Flavonoid-Series, IV. Synthesis of Chrysin-7-β-D-glucopyranuronide, -7-β-D-neohesperidoside and -7-β-D-rutinosideCoupling of chrysin with methyl(tri-O-acetyl-α-D-glucopyranosyl bromide)uronate, followed by total acetylation and subsequent removal of the protecting groups yielded chrysin-7-β-D-glucopyranuronide (2). Chrysin-7-β-D-neohesperidoside (5), starting material to get chrysin, was prepared by dehydrogenation of 5.7-dihydroxyflavanone-7-β-D-neohesperidoside heptaacetate with iodine and potassium acetate and subsequent deacetylation. Condensation of chrysin with α-acetobromorutinose, followed by deacetylation of the product resulted in the formation of chrysin-7-β-D-rutinoside (7).
    Notes: Durch Kupplung von Chrysin mit α-Acetobromglucuronsäure-methylester und Verseifen des dargestellten Vollacetats wurde 5.7-Dihydroxy-flavon-7-β-D-glucopyranosiduronsäure (Chrysin-7-β-D-glucopyranuronid) (2) synthetisiert. Chrysin-7-β-D-neohesperidosid (5), die unmittelbare Ausgangsverbindung für die Chrysinherstellung, wurde durch Dehydrierung von 5.7-Dihydroxy-flavanon-7-β-D-neohesperidosid-heptaacetat mit Jod und Kaliumacetat und anschließende Entacetylierung dargestellt. Glykosidierung von Chrysin mit α-Acetobromrutinose und anschließende Verseifung des Teilacetats ergab Chrysin-7-β-D-rutinosid (7).
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 3850-3864 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photoelectron Spectra and Molecular Properties, XIVThe Sulfur Lone Pair Delocalization in CH3S-Substituted Aromatic SystemsPhotoelectron (PE) spectra and charge transfer excitation energies of 16 derivatives of benzene, naphthalene and styrene with substituents X == SCH3, CH2SCH3, OCH3, and CH2OCH3 are discussed. PE-splitting patterns can be understood qualitatively as π-perturbations, and can be explained quantitatively in terms of π-SCF-calculations. The PE ionization potentials of sulfides can be linearly correlated with the CT excitation energies of their s̰- and π-complexes with tetracyanoethylene. In summary, the delocalisation of the sulfur lone pair in the ground state of aromatic π-systems can be described in terms of a „p-model“ neglecting „pπ/dπ“ back-bonding.
    Notes: Von 16 Benzol-, Naphthalin- und Styrol-Derivaten mit Substituenten X == SCH3, CH2SCH3, OCH3 und CH2OCH3 werden die Photoelektronen(PE)-Spektren und die Charge Transfer-Anregungsenergien vergleichend diskutiert. Die PE-Aufspaltungsmuster können qualitativ als π-Störung und quantitativ durch π-SCF-Rechnungen erfaßt werden. Zwischen den PE-Ionisierungsenergien der Sulfide und den CT-Anregungsenergien ihrer s̰- und π-Tetracyanäthylen-Komplexe bestehen lineare Beziehungen. Insgesamt läßt sich die Delokalisation des Schwefel-Elektronenpaares im Grundzustand aromatischer π-Systeme mit einem „p-Modell“ ohne zusätzliche „pπ/dπ“-Rückbindung beschreiben.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 68-77 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photoelectron Spectra and Molecular Properties, XXVI. The Delocalisation of Sulfur Electron Pairs in Sulfides and DisulfidesThe photoelectron (PE) spectra of sulfides R—S—R (R=H, CH3, C2H5, n- und i-C3H7, n- and tert-C4H9) and disulfides R—S—S—R (R=H, CH3, C2H5, n- and i-C3H7, tert-C4H9, —[CH2]4—) are comparatively discussed. For sulfides the first ionization energy, which decreases as expected with increasing degree of alkylation, can also be obtained from the charge transfer excitation energies of their σ-complexes with tetracyanoethylene (TCNE). Disulfides show a splitting of the first PE-band in a clear dependence on the dihedral angle of the sulfur electron pairs. All observations can be rationalised within MO models as interactions of the sulfur electron pairs with the σ-skeleton and/or with each other.
    Notes: Die Photoelektronen(PE)-Spektren von Sulfiden R—S—R (R=H, CH3, C2H5, n- und i-C3H7, n- und tert-C4H9) und Disulfiden R—S—S—R (R=H, CH3, C2H5, n- und i-C3H7, tert-C4H9, —[CH2]4—) werden vergleichend diskutiert. Bei den Sulfiden R—S—R kann die mit steigendem Alkylierungsgrad erwartungsgemäß abnehmende erste Ionisierungsenergie auch aus den Charge-transfer-Anregungsenergien ihrer σ-Komplexe mit Tetracyanäthylen (TCNE) abgelesen werden. Bei Disulfiden R—S—S—S—R wird eine Aufspaltung der ersten PE-Bande in deutlicher Abhängigkeit vom Diederwinkel zwischen den Schwefel-Elektronen-paaren beobachtet. Die Befunde lassen sich mit MO-Modellen als Wechselwirkungen der Schwefel-Elektronenpaare mit dem σ-Gerüst und/oder untereinander verstehen.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 305-316 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Benzothiazole N-Oxides, II. New Synthesis of Substituted 2-BenzothiazolonesIn the presence of phosphoryl chloride, 2-carbamoylbenzothiazole N-oxides undergo a new intramolecular redox reaction to give 2-benzothiazolones. In two cases investigated, also 2-ethoxycarbonylbenzothiazole N-oxides undergo this rearrangement. The spectroscopic data are discussed.
    Notes: 2-Carbamoylbenzothiazol-N-oxide gehen in Gegenwart von Phosphoroxychlorid eine neuartige intramolekulare Redoxreaktion unter Bildung von 2-Benzothiazolonen ein. In zwei untersuchten Fällen unterliegen unterliegen auch 2-Äthoxycarbonylbenzothiazol-N-oxide dieser Umlagerung. Spektroskopische Daten werden diskutiert.
    Additional Material: 7 Tab.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Structure of Moldavoside.  -  Synthesis of Acacetin-7-β-D-galactopyranosideThe glycoside moldavoside, isolated from Dracocephalum moldavica, was assigned the structure acacetin-7-β-D-galactopyranoside by Litvinenko et al. Coupling of isosakuranetin and α - acetobromogalactose followed by dehydrogenation of the resulting flavanone glycoside yielded acacetin-7-β-D-galactopyranoside. The synthetic glycoside was not identical with moldavoside. Moldavoside however showed identity with tilanine (acacetin-7-β-D-glucopyranoside). Therefore the name moldavoside is to be deleted from the literature.
    Notes: Einem aus Dracocephalum moldavica (Türkische Melisse) isolierten Glykosid, Moldavosid, wurde von Litvinenko und Mitarbb. die Struktur eines Acacetin-7-β-D-galaktopyranosids gegeben. Durch Kupplung von Isosakuranetin und α-Acetobromgalaktose sowie Dehydrierung des entstandenen Flavanonglykosids synthetisierten wir Acacetin-7- β-D-galaktopyranosid, das mit Moldavosid jedoch nicht identisch war. Dagegen zeigte das Moldavosid Übereinstimmung mit Tilianin (Acacetin-7-β-D-glucopyranosid). Der Name Moldavosid ist daher aus der Literatur zu streichen.
    Type of Medium: Electronic Resource
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