Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Metallorganische Verbindungen, XXV Aluminiumtrialkyle und Dialkyl-aluminiumhydride als Reduktionsmittel2) (1959)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 623 (1959), S. 9-16 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Diisobutyl-aluminiumhydrid und Aluminiumtriisobutyl verhalten sich aromatischen und α.β-ungesättigten Aldehyden sowie Chloral und ω-Trichlor-acetophenon gegenüber wie Mischungen von Aluminiumhydrid und Isobutylen: Je Aluminiumatom werden 3 Moleküle der Carbonylverbindung reduziert. Dialkyl-aluminiumhydride mit normalen Resten reagieren den gleichen Stoffen gegenüber fast stets (Ausnahme: Chloral) nur mit ihrer A1 - H-Gruppe. Ketone, Carbonsäureester, Nitrile und Schiffsche Basen reagieren in allen Fällen nur mit der einen Al - H-Bindung der Dialkyl-aluminiumhydride. Aluminiumtriisobutyl verhält sich den gleichen Stoffen gegenüber wie eine Mischung von Isobutylen und Diisobutyl-aluminiumhydrid. Alle diese Reaktionen sind denen des LiAlH4 analog.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.19596230103
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Untersuchungen an Cyclopropan-Verbindungen, XIII. Umlagerungen von Cycloalken-(1)-yl-äthyl-Verbindungen in Cyclopropanspiro- und Bicyclo[n.2.0]alkyl-Systeme (1968)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 717 (1968), S. 41-53 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Cyclohepten-(1)-yl-, Cycloocten-(1)-yl- und Cyclononen-(1)-yl-äthylamin (1, X = NH2, n = 5-7) ergeben bei der Desaminierung mit salpetriger Säure unter Beteiligung der Doppel-bindung neben anderen Produkten die Cyclopropan-spiroalkohole 2 (Y = OH) und die Cyclobutanole 3 (Y = OH). Das Verhältnis von 2 zu 3 wird vom pH-Wert der Reaktionslösung bei der Desaminierung bestimmt. Cycloalken-(1)-yl-äthyltosylate (1, X = OSO2C6H4CH3-p) solvolysieren in Aceton/Wasser (20 : 80) bevorzugt zu den Cyclopropan-spiroalkoholen 2 (Y = OH). Der Mechanismus der Isomerisierung wird anhand der genauen Produktanalysen dieser Reaktionen sowie der Produkte diskutiert, die bei Solvolysen von Cyclopropanspiro- 2 und kondensierten Cyclobutan-Derivaten 3 erhalten werden. Die Nachbargruppen-Wirkung der Doppelbindung wird mit Hilfe kinetischer Methoden am Cyclohexen-(1)-yl-äthyltosylat untersucht. Die Aktivierungsenthalpien und -entropien bei der Solvolyse des Cyclohexen-(1)-yl-äthyltosylates in 30-, 50- und 70 proz. Aceton unterscheiden sich nur wenig. Dagegen ergibt das gesättigte Vergleichssystem in 30 proz. Aceton eine stärker negative Entropie. Der Vergleich der Solvolyse-Geschwindigkeiten sowie der Aktivierungs-parameter läßt den Schluß zu, daß die Nachbargruppen-Wirkung der Doppelbindung primär eine Verschiebung zu einer SN 1-Reaktion hin bewirkt. Dies wird durch systematische Messungen der Hydrolyse-Geschwindigkeiten in Lösungsmitteln verschiedener Ionisierungsstärke bestätigt (Tab. 5). Die Solvolyse-Konstanten von bicyclischen Cyclopropylmethyl- und Cyclobutyl-p-nitrobenzoaten zeigen die erwartete nichtklassische Stabilisierung der entsprechenden Carbonium-Ionen an.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.19687170104
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Automatisches acidimetrisches Verfahren zur Messung von Solvolyse-Geschwindigkeiten (1969)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 722 (1969), S. 234-236 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Automatic Acidimetric Procedure for Measuring Rates of SolvolysisA method for the continuous determination of reaction rates by means of an automatic titrator is described (figure 1). The scope of the technique as well as its precision and accuracy are discussed (figure 2).
    Notes: Zur kontinuierlichen Reaktionsgeschwindigkeitsbestimmung dient ein pH-Stat (Abb. 1). Die Anwendungsbreite des Verfahrens sowie Reproduzierbarkeit und Fehler werden dargestellt (Abb. 2).
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.19697220126
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Bildungsweisen und Solvolysen von tertiären 2-Bicyclo[2.2.1]-heptylestern (1975)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1975 (1975), S. 1690-1699 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Mode of Formation and Solvolyses of Tertiary 2-Bicyclo[2.2.l]heptyl EstersPreparation and solvolyses of the tertiary chlorides obtained by hydrogen chloride addition to 2-methylenenorbornane, camphene, and α- and β-fenchene are discussed. Neither these reactions nor reinvestigated reactions with fenchyl chlorides yielded any tertiary endo chlorides. The solvolysis results with p-nitrobenzoates of β-fenchene hydrates and other tertiary alcohols can be rationalized by intramolecular steric interactions without invoking charge delocalized intermediates.
    Notes: Darstellung und Solvolysen der aus 2-Methylennorbornan, Camphen, α- und β-Fenchen erhaltenen tertiären Chloride werden beschrieben. endo-Chloride konnten in keinem Fall nachgewiesen werden, auch nicht bei der Neuuntersuchung früher beschriebener Reaktionen mit Chloriden der Fenchanreihe. Die Solvolyseergebnisse mit den p-Nitrobenzoaten von endo- und exo-β-Fenchenhydrat und anderen epimeren p-Nitrobenzoaten lassen sich ohne Annahme ladungsdelokalisierter Zwischenstufen durch intramolekulare sterische Wechsel- wirkungen verstehen.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197519750916
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Synthesis and Anaphylactogenicity of Monohaptenic Carbohydrate Conjugates (1983)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 66 (1983), S. 1101-1109 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Peptidic model conjugates carrying a single 2-carboxy-4,6-dinitrophenyl haptenic group, and as carbohydrate moieties D-gluconoyl, β-D-mannopyranosyl, 2-deoxy-β-D-glucopyranos-2-yl, or lactobionoyl residues, including the pseudocarbohydrate residue 1,3,4,5-tetrahydroxycyclohexane-1-carbonyl, were synthesized. Conjugates carrying the lactobionoyl of the bis(2-deoxy-β-D-glucopyranos-2-yl) moiety were anaphylactogenic in the guinea pig, passively sensitized against 2-carboxy-4,6-dinitrophenyl antigen.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19830660413
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Preparation and Conformational Properties of Benzylpenicilloyl-oligo-L-lysine Conjugates (1982)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 65 (1982), S. 1965-1971 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Selected oligo-L-lysine carriers and a poly-L-lysine were penicilloylated with benzylpenicillin. The resulting conjugates 2-6 were studied by IR. absorption in the solid state and circular dichroism measurements in solution. The IR. data demonstrate the lack of β-structure formation even in medium-sized peptides where such structures might be expected on the basis of previous studies on differently substituted oligo-L-lysines. Considerable proportions of right-handed α -helical conformation are exhibited by the icosa-L-lysine and poly-L-lysine conjugates 5 and 6 in water and 2,2,2-trifluoroethanol. Difficulties in obtaining fully penicilloylated conjugates are not related to the extent of α-helical conformation in aqueous solution.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19820650703
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Monohaptenic Nα-Benzoyl-L-lysine Derivatives as Anaphylactogens: the Importance of the Unsubstituted Carboxyl Group (1984)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 67 (1984), S. 1000-1002 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Nα-L-Iysine with a 2-carboxy-4, 6-dinitrophenyl (Dncp) haptenic group on the ε-amino function is a potent anaphylactogen in the guinea pig. We prepared Nε -Dncp- Nα-benzoly-L-Iysinamide and Nε-Dncp-Nα-benzoyl-L-lysyl-1-aminopropane where the carboxyl group of Iysine is blocked. Both compounds were non-elections of anaphylaxis.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19840670411
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    (Cholestanyloxycarbonyl)benzyl esters as peptide substituents: Conformational properties of fully protected oligo-L-lysines with C-terminal (cholestanyloxycarbonyl)benzyl and benzyl ester moieties (1986)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 69 (1986), S. 350-358 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: This study involves L-lysine oligo peptides, protected at the N-terminus by the Nps and at the ε-amino functions by Boc groups. Two series were prepared from dimer to octamer, one containing the p-[(cholestan-3β-yloxy)carbonyl]benzyl, the other one the benzyl ester group at the C-terminus. Conformational analyses were performed by IR absorption. The occurrence of the intermolecular β-structure in the solid state and in CH2Cl2 solution was demonstrated for the highest oligomers. The relative stabilities of the self-associated species were determined by adding a variety of polar solvents to the CH2Cl2 solutions. The cholestanyl-containing peptides have a lower propensity to self-aggregate than the benzyl-ester analogues. Self-aggregation and decreasing solubility run in parallel. It was also directly shown that soluble urea derivatives may disrupt intermolecular H-bonds in CH2Cl2, a point of practical interest, particularly in solid-phase peptide synthesis.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19860690214
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Enantioselective Synthesis of β-Necrodol and of 1-Epi-β-necrodol via Asymmetric 1,4-Addition and Magnesium-Ene Cyclization. Preliminary Communication (1986)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 69 (1986), S. 1817-1820 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Enantiomerically pure β-necrodol (1) and its 1-epimer 16 have been synthesized starting from aldehyde 5. The two key steps are an asymmetric conjugate addtion/Mannich reaction tandem (10→12) and a type-II-magnesiumene cyclization/oxidation sequence (14→1 + 16).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19860690805
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Syntheses of Tetrahydrolipstatin and Absolute Configuration of Tetrahydrolipstatin and Lipstatin (1987)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 70 (1987), S. 196-202 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Lipstatin (1), a natural product, and tetrahydrolipstatin (2) are pancreatic lipase inhibitors. Non-stereoselective and partially stereoselective syntheses of 2 are used to establish the absolute configuration of tetrahydrolipstatin and lipstatin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19870700124
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...