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  • 1
    Electronic Resource
    Electronic Resource
    Preparation and steric structure of 3(2H)-pyridazinones and 1,2-oxazin-6-ones fused with three- to six-membered saturated carbocycles or norbornane skeleton (1994)
    Springer
    Monatshefte für Chemie 125 (1994), S. 933-944 
    Details
    ISSN: 1434-4475
    Keywords: Cycloalkanes ; Heterocycles ; Friedel-Crafts acylation ; Isomerization ; Methyloctahydro-anthracen-9-ones ; Reduction ; LAH/AlCl3
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Die Reaktion voncis-2-(4-methylbenzoyl)-cyclopropan-(1) und-cyclobutancarbonsäuren (2), der stereoisomeren cyclohexyl-Homologen (3 und4) und von di-endo-3-(4-methylbenzoyl)-bicyclo[2.2.1]heptan-2-carbonsäure (5) mit Hydrazinen ergibt die cycloalkankondensierten 3(2H)-Pyridazinone6–9 und das methylenüberbrückte di-endo-Derivat10. Die Verbindungen1 und3–5 wurden mit Hydroxylamin zu den cycloalkan- und norbornankondensierten 1,2-Oxazin-6-onen11–14 umgesetzt.3–6 reagierten zumtrans-Hexahydroanthron17a und seinem methylenüberbrückten Analogen24. Die teilweise gesättigten Anthrone wurden auch aus den stereoisomeren Hexahydro-1(3H)-isobenzofuranonen20 und21 hergestellt (16b und17b), wobei der Methylsubstituent jedoch in Position 6 lokalisiert ist. Reduktion von16b ergab das 2-Methyloctahydroanthracen22. Die Strukturen der Verbindungen wurden durch NMR-Spektroskopie abgesichert (1H,13C, DEPT, CH-COSY, NOE).
    Notes: Summary Reactions ofcis-2-(4-methylbenzoyl)-cyclopropane- (1) and-cyclobutanecarboxylic acids (2), the stereoisomeric cyclohexyl homologues (3 and4), and di-endo-3-(4-methylbenzoyl)-bi-cyclo-[2.2.1]heptane-2-carboxylic acid (5) with hydrazines yield the cycloalkane-condensed (3(2H)-pyridazinones6–9 and the norbornane di-endo-fused derivatives10. With hydroxylamine, compounds1 and3–5 were transformed to the cycloalkane- and norbornane-condensed 1,2-oxazin-6-ones11–14. Transformation of3–5 led to thetrans-hexahydroanthrone17a and its methylene-bridged analogue24. From the stereoisomeric hexahydro-1(3H)-isobenzofuranones20 and21, the partly saturated anthrones were also prepared; the products (16b and17b) contain the methyl substituent in position 6. On reduction,16b yield the 2-methyloctahydroanthracene22. The structures of the compounds were proved by1H and13C NMR spectroscopy, making use of NOE, DEPT, and CH-COSY techniques.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00812708
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  • 2
    Electronic Resource
    Electronic Resource
    Synthese und Molekülstruktur neuer Ringsysteme aus 1,1,3,3-Tetrachlor-1,3-diphosphapropan (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 908-913 
    Details
    ISSN: 0044-2313
    Keywords: Methylene-bridged Phosphines ; Phosphaalkenes ; Heterocycles ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Molecular Structure of new Ring Systems from 1,1,3,3-Tetrachloro-1,3-diphosphapropane1,1,3,3-Tetrachloro-1,3-diphosphapropane 1 reacts in two different ways to form new heterocycles. Partial oxidation of 1 with tetrachloroorthobenzoquinone furnishes the methylene-bridged λ3P, λ5P species 3. Subsequent reactions with di- and triethylamine lead to the condensed ring system 6 with the P=C bonds connected to a central four-membered ring. Compound 6 displays crystallographic inversion symmetry, a short transannular P—P distance and an extremely distorted tetrahedral coordination geometry at the four-membered ring phosphorus atoms. 1 reacts with 7 to give the heterocycle 8 with a central eight-membered ring involving four phosphorus atoms. The eight - membered ring shows a „bent“ crown conformation, the condensed five - membered rings display envelope conformation.
    Notes: Aus 1,1,3,3-Tetrachlor-1,3-diphosphapropan 1 lassen sich auf zwei verschiedenen Reaktionswegen neue Heterocyclen gewinnen. Die Oxidation von 1 mit einem Äquivalent Tetrachlororthobenzochinon führt zu der methylenverbrückten λ3P, λ5P Spezies 3. Bei der anschließenden Umsetzung mit Di- und Triethylamin entsteht das kondensierte Ring-system 6 mit am zentralen Vierring exocyclisch angeordneten P=C Bindungen. 6 zeigt kristallographische Inversionssymmetrie, einen kurzen P—P Transannularabstand und eine extrem verzerrte tetraedrische Koordinationsgeometrie an den λ5-Phosphoratomen. 1 und 7 reagieren unter Bildung eines Heterocyclus mit einem zentralen Achtring mit vier alternierend angeordneten Phosphoratomen. Der Achtring liegt in einer „geknickten“ Kronenform vor, die ankondensierten Fünfringe besitzen Briefumschlagkonformation.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946200525
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  • 3
    Electronic Resource
    Electronic Resource
    13C NMR chemical shifts of heterocycles. Empirical substituent effects in 5-halomethyl-5-hydroxy-4,5-dihydroisoxazoles (1994)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 32 (1994), S. 614-616 
    Details
    ISSN: 0749-1581
    Keywords: 13C NMR ; 4,5-Dihydroisoxazoles ; Substituent effects ; Heterocycles ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Evaluation by empirically derived equations for the substituent effect (α, β, γ, δ) on the 13C NMR chemical shifts for C-3, C-4, C-5 and halomethyl-substituent carbon (C-6) in 5-halomethyl-5-hydroxy-4,5-dihydroisoxazoles (where C-3 substituent=H), alkyl or phenyl, C-4 substituent=H, alkyl or heteroalkyl and C-5 substituent (=dior trihalomethyl), taking as reference 5-trichloromethyl-5-hydroxy-4,5-dihydroisoxazole, is reported. From the calculated values for the α, β, γ and δ effects for each substituent it was possible to estimate the chemical shift of each carbon of the compounds.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1260321009
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  • 4
    Electronic Resource
    Electronic Resource
    Impact of some commonly used Egyptian diets on plasma lipids profils of rats (1993)
    Springer
    European journal of nutrition 32 (1993), S. 229-236 
    Details
    ISSN: 1436-6215
    Keywords: Fibers ; rats ; Plasma lipids ; Ratten ; Plasmalipide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung An hyperlipämischen Ratten wurde der Einfluß von 7 üblichen ägyptischen Kostformen geprüft. Die Ernährung bestand aus weißen Bohnen und Weizenvollkornbrot (Diät 1), Kohl und Erbsen (2), Spinat und Karotten (3), Weizenvollkornbrot und Bohnensprossen (4), Weizenvollkornbrot, weißen Bohnen und Erbsen (5), weißen Bohnen und Karotten (6) und schließlich Erbsen und Karotten (7). Die Versuche dauerten 5 Wochen, danach wurden verschiedene Plasmalipide und biologische Parameter mit hyperlipämischen Kontrolltieren verglichen. Das Gesamtplasmacholesterol war in allen Versuchsgruppen erniedrigt; eine Ausnahme machte Diät 6, hier gab es keine Senkung. Erniedrigt waren die Gesamtplasmalipide in Gruppe 5. Plasmaphospholipide stiegen an in den Gruppen 3 und 7. In Gruppe 3 war das HDL-Cholesterol erniedrigt. Die Gewichtszunahmen in den Gruppen 1, 2 und 3 waren reduziert. Ein verminderter Futterverzehr wurde in den Gruppen 1 und 6 beobachtet. Die Futterverwertung sank in den Gruppen 1, 5 und 6. In allen 7 Gruppen war das Gewicht der Faeces erhöht.
    Notes: Summary Seven types of diets commonly consumed in Egypt were studied in hyperlipemic rats. Each of the seven diets were fed to a group of hyperlipemic rats. The diets contain white beans and whole wheat bread (Diet 1); cabbage and peas (2); spinach and carrots (3); whole wheat bread and bean sprouts (4); whole wheat bread, white beans and peas (5); white beans and carrots (6) and the last diet contains peas and carrots (7). The experiment continued for 5 weeks, at the the of which different plasma lipids and biological parameters were compared to hyperlipemic rats fed the control diet for 5 weeks. Results showed that plasma total cholesterol of rats of all groups showed significant decrease, except in rats fed diet 6 in which no significant change was noticed. Plasma total lipids of rats fed diet 5 decreased significantly. Plasma phospholipids of rats fed diets 3 and 7 increased significantly. Rats fed diet 3 showed decreased levels of plasma high density lipoprotein-cholesterol. Body weight gain of rats fed diets 1, 2 and 3 decreased significantly. Total food intake was noticed to decrease on feeding diets 1 and 6. Significant decrease was produced in food efficiency ratio of rats fed diets 1, 5 and 6. Feeding any type of the previous seven diets produced significant increase of feces weight.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01610733
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  • 5
    Electronic Resource
    Electronic Resource
    Elucidation of the constitution of a heterocyclic rearrangement product by means of17O-NMR-spectroscopy (1993)
    Springer
    Monatshefte für Chemie 124 (1993), S. 1195-1200 
    Details
    ISSN: 1434-4475
    Keywords: Spiro compounds ; Heterocycles ; Rearrangement ; 17O-NMR
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Im Verlauf einer versuchten Eliminierungstreaktion wurde ausgehend von einem Aminoalkoholderivat eines Isothiochromansystems unerwarteterweise ein Benzo[c]thiophen-derivat isolert. Die Konstitution des Umlagerungsproduktes wurde eindeutig durch17O-NMR-Spektroskopie bestätigt.
    Notes: Summary In the course of an attempted elimination reaction starting from an isothiochromane derivative substituted with an amino-alcohol moiety, a benzo[c]thiophene derivative formed via a rearrangement reaction was isolated unexpectedly. Its constitution was confirmed unambiguously via17O-NMR-spectroscopy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00810028
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  • 6
    Electronic Resource
    Electronic Resource
    1H and 13C NMR studies of E/Z 2-hydroxyindolenines (1993)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 31 (1993), S. 960-962 
    Details
    ISSN: 0749-1581
    Keywords: E/Z 2-hydroxyindolenines ; 1H-NMR ; 13C-NMR ; Heterocycles ; Substituent effects ; Conformation ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The 1H NMR spectra of E/Z 2-hydroxyindolenines are reported in both CDCl3 and DMSO-d6 solvents. The data suggest a preferred conformation of the heterocyclic ring, which is slightly distorted from planarity, in agreement with the x-ray crystallographic data of one of the isomers. The 13C NMR spectra for the Z-hydroxyindolenines are also described. Substituent effects on E/Z isomerism about the exocyclic C=C bond are discussed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1260311015
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  • 7
    Electronic Resource
    Electronic Resource
    Development of a computer model to predict strains in the individual fibers of a ligament across the ligamentous occipito-atlanto-axial (C0-C1-C2) complex (1992)
    Springer
    Annals of biomedical engineering 20 (1992), S. 667-686 
    Details
    ISSN: 1573-9686
    Keywords: Fibers ; Ligaments ; Computer model ; Strains
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Abstract A fresh ligamentous occipito-atlanto-axial (C0-C1-C2) complex was appropriately prepared and serially sectioned into thin slices along the transverse planes. The bony outlines from these slices were digitized and assembled in the proper manner to obtain a three-dimensional model of the complex using the AutoCAD® system. Various ligaments were identified on the model and strains in individual fibers of a ligament were predicted based on the principles of rigid body mechanics. The ligament behaviors in axial rotation, flexion, and extension modes were analyzed. The capsular ligament fibers were predicted to undergo strains in all modes. Furthermore, these ligaments experienced the largest strain among the ligaments analyzed. Fibers within a ligament were found to respond differently; some were more active than the others and some did not experience any strain at all. A differential behavior in the right and left side alar ligament fibers was also found in axial rotation. The transverse ligament was predicted to wrap around the dens during axial rotation. The strain within a fiber was found to be a function of the initial length (ligament laxity) and its distance from the center of rotation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02368612
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  • 8
    Electronic Resource
    Electronic Resource
    Transformation of acridines and azepines into the corresponding 3-oxo-heterocycles by means of hypervalent aromatic iodine compounds (1991)
    Springer
    Monatshefte für Chemie 122 (1991), S. 323-325 
    Details
    ISSN: 1434-4475
    Keywords: Bis-(trifluoroacetoxy)pentafluoroiodobenzene ; Iodosylbenzene ; Oxidation ; Heterocycles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Die Acridine3,5 und6 sowie das Dibenzo[b,f]azepin4 wurden mit Hilfe der beiden hypervalenten Jod-Verbindungen Jodosobenzol (1) und Bis-trifluoroacetoxyiodbenzol (2) zu den entsprechenden 3-Acridinonen7,9 und10 sowie zum Dibenzoazepin-3-on8 oxidiert.
    Notes: Summary The acridines3,5, and6, as well as the dibenzo[b,f]-azepine4 were converted into the 3-oxo-derivatives7–10 using hypervalent iodine compounds (iodosylbenzene and bis-(trifluoroacetoxy)iodopentafluorobenzene).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00810833
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  • 9
    Electronic Resource
    Electronic Resource
    Design of high-capacity, reversible polymeric adsorbents for acidic gases (1991)
    New York, NY : Wiley-Blackwell
    Polymers for Advanced Technologies 2 (1991), S. 87-91 
    Details
    ISSN: 1042-7147
    Keywords: Adsorption of CO2 and SOx ; Polyamines ; High Capacity ; Reversible ; Fibers ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Polyethyleneimine (PEIM) samples crosslinked by a commercial epoxy resin (Epon 828) were prepared, and their adsorption capacity for acidic gases was studied. The swelling and deswelling characteristics of the crosslinked samples were also examined as part of this program. Reactivation of these adsorbents could be carried out by heat, or by a combination of heat and treatment in dilute alkalies.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pat.1991.220020206
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  • 10
    Electronic Resource
    Electronic Resource
    Iminophosphanes: Unconventional Compounds of Main Group ElementsDedicated to Professor Rolf Appel on the occasion of his 70th birthday (1991)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 30 (1991), S. 217-237 
    Details
    ISSN: 0570-0833
    Keywords: Coordination number ; Phosphorus-nitrogen compounds ; Bond theory ; Heterocycles ; Imino phosphanes ; Phosphanes ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The large number of known stable compounds in which phosphorus has a low coordination number makes it clear that such compounds can no longer be regarded as “exotic” in main group chemistry. While the rich chemistry of P—C multiply bonded systems makes clear their affinity to their organic congeners, iminophosphanes in particular are also of increasing importance. The linkage of a phosphinidine fragment with an imine fragment via a multiple bond gives rise to a class of compounds with an unusually wide range of structural types. This in turn leads to a broad spectrum of chemical behavior which makes iminophosphanes extremely useful synthetic building blocks in organoelement chemistry.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.199102173
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  • 11
    Electronic Resource
    Electronic Resource
    3-Amino-2H-Azirines. Synthons for α,α-Disubstituted α-Amino Acids in Heterocycle and Peptide Synthesis [New Analytical Methods (43)] (1991)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 30 (1991), S. 238-264 
    Details
    ISSN: 0570-0833
    Keywords: 3-Amino-2H-azirines ; Azirines ; Amino acids ; Peptides ; Heterocycles ; Synthetic methods ; 2-Aminoisobutyric acid ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The recent upswing in peptide chemistry has been accompanied by an increasing interest in nonproteinogenic amino acids. These include the α,α-disubstituted glycines, the best known of which is Aib (2-aminoisobutyric acid, 2-methylalanine). These α-amino acids occur in natural oligopeptides such as the peptaibols, a class of membrane-active ionophores that has been isolated from fungal cultures. The twofold substitution at the α-C atom of the amino acids severely restricts the conformational freedom of the peptides and causes particular secondary structures to be favored; thus, α, α-disubstituted α-amino acids induce the formation of β turns or helices. 3-Amino-2H-azirines are ideal synthons for the construction of oligopeptides, cyclic peptides and depsipeptides (peptolides) containing such α,α-disubstituted α-amino acids. The presence of the ring strain in these molecules means that they can be used in peptide coupling without the need for additional activating reagents. Using 3-amino-2H-azirines a large array of heterocycles containing α, α-disubstituted α-amino acids as structural elements within their skeleton can be synthesized. The driving force in these reactions is the release of the strain on the three-membered ring, which usually takes place in a ring-expansion reaction. The mechanistic elucidation of these reactions, which can be quite complex, contains some surprises.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.199102381
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  • 12
    Electronic Resource
    Electronic Resource
    Occurrence of bombesin-like immunoreactivity in the brain of the cartilaginous fish,Scyliorhinus canicula (1990)
    Springer
    Cell & tissue research 259 (1990), S. 177-181 
    Details
    ISSN: 1432-0878
    Keywords: Bombesin-like peptide ; Immunocytochemistry ; Hypothalamus ; Neurosecretory ; Fibers ; Scyliorhinus canicula (Elasmobranchii)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The presence and distribution of bombesin-like material were investigated in the brain of the cartilaginous fishScyliorhinus canicula using conventional immunocytochemical techniques. Perikarya containing bombesin-like immunoreactivity were identified in the hypothalamus, within the magnocellular component of the preoptic nucleus. Some immunopositive elements appeared to be of cerebrospinal fluid-contacting type. Beaded immunoreactive fibers were seen crossing the ventral telencephalon and the whole hypothalamus. An important tract of fibers was found in the infundibular floor and in the median eminence, in close contact with the vascular system of the pituitary portal plexus. A moderate number of positive fibers innervated the habenular complex and the dorsal wall of the posterior tuberculum. These findings indicate that a neuropeptide strictly related to amphibian bombesin is located in specific hypothalamic neurons ofS. canicula. The distribution of the immunoreactive fibers and terminals suggests that, in fish, this peptide, may be involved in neuroendocrine and neuromodulator functions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00571441
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  • 13
    Electronic Resource
    Electronic Resource
    SAXS experiments on gel-spun polyethylene fibers (1990)
    Springer
    Colloid & polymer science 268 (1990), S. 245-255 
    Details
    ISSN: 1435-1536
    Keywords: Fibers ; polyethylene ; gel-spinning ; smallanglex-rayscattering ; spinningconditions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The properties of gel-spun polyethylene fibers hot-drawn to the maximum draw ratio depend on the spinning conditions. Different spinning conditions result in two types of structure in the paraffin oil containing fibers: an isotropic lamellar structure or a shish-kebab structure. Meridional SAXS experiments can identify the structure present. After extraction, these structures are still present but can be detected only in a more indirect way by SAXS experiments because of an excessive contribution of void scattering. During hot-drawing both structures are transformed into a more fibrillar structure. The shish-kebab structures can be drawn only to relatively low hot-draw ratios with an incomplete transformation of the lamellar overgrowth into the fibrils, as demonstrated by the presence of a meridional SAXS maximum/shoulder. This leads to relatively weak fibers. Lamellar structures can be drawn to high draw ratios by chain unfolding. A nearly complete transformation of the lamellae into fibrils is obtained and the fibers have excellent properties. The information about the morphology obtained by SAXS, DSC, WAXS, and SEM can be used to establish a relation between morphology and properties.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01490249
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  • 14
    Electronic Resource
    Electronic Resource
    Three-Membered Rings Containing Two Hetero-Atoms (1964)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 3 (1964), S. 333-341 
    Details
    ISSN: 0570-0833
    Keywords: Strained molecules ; Heterocycles ; Diaziridines ; Diazirines ; Oxaziranes ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Since their discovery five years ago, the diaziridines have become an extensive and easily accessible class of compounds. Hydrolysis of these compounds effects a simple synthesis of hydrazine, alkylhydrazines, and N,N′-dialkylhydrazines. They are also powerful oxidizing agents. The rigidity of the three-membered ring gives rise to a few stereoelectronic peculiarities. Investigations on the mechanism of formation of the three-membered rings led to a new synthesis of oxaziranes and to discovery of the isomeric oximes with a three-membered ring structure. The latter decompose readily to form diimide. Diazirines are cyclic isomers of the aliphatic diazo compounds and are surprisingly easy to obtain by dehydrogenation of suitable diaziridines; they are chemically much more stable than the linear isomers. Grignard reagents add onto the N=N double bond without destruction of the three-membered ring. Thermal decomposition yields carbenes.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.196403331
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  • 15
    Electronic Resource
    Electronic Resource
    The Chemistry of New Heat-Resistant Films and Fibers (1964)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 3 (1964), S. 460-470 
    Details
    ISSN: 0570-0833
    Keywords: Heat resistance ; Fibers ; Polymers ; Materials science ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: This survey is principally concerned with papers published since 1959 on hydrocarbon polymers, aliphatic poly(terephthalamide) fibers, poly(hydroxybenzoic acid) films, poly(oxadiazole) fibers, poly(benzimidazole) films, poly(phenyltriazole) films, poly(pyromellitimide) films, and fibers from cyclized poly(acrylonitrile). All these materials have extremely high melting points and satisfactory in-use characteristics at high temperatures.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.196404601
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  • 16
    Electronic Resource
    Electronic Resource
    Kinetics and Mechanism of 1,3-Dipolr CycloadditionsExtended version of a lecture given at the Annual Meeting of the Dechema in Frankfurt/Main on June 14th, 1962, and of the Max Tishler Lecture at Harvard University on December 10th, 1962. (1963)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 2 (1963), S. 633-645 
    Details
    ISSN: 0570-0833
    Keywords: Kinetics ; Dipolar cycloaddition ; Cycloaddition ; Heterocycles ; Reaction mechanisms ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Criteria for the mechanism of 1,3-dipolar cycloadditions which lead to 5-membered rings are provided by the stereoselectivity observed with cis-trans isomeric dipolarophiles, by the effect of solvent and substituents on the rate constants, by the activation parameters, and by orientation phenomena. A concerted addition, which can also be described in terms of molecular orbitals and in which the two new σ-bonds are formed simultaneously, although not necessarily at equal rates, offers the best explanation of the experimental facts.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.196306331
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  • 17
    Electronic Resource
    Electronic Resource
    Syntheses of Heterocyclic Compounds from Aminoguanidine (1963)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 2 (1963), S. 459-476 
    Details
    ISSN: 0570-0833
    Keywords: Aminoguanidine ; Heterocycles ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Due to its unique structure, aminoguanidine is capable of reacting as a derivative of hydrazine, guanidine or formamidine. Addition and condensation reactions yield products which can be cyclized to heterocyclic compounds. Frequently, heterocyclics are directly accessible from aminoguanidine in one stage.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.196304591
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  • 18
    Electronic Resource
    Electronic Resource
    1,3-Dipolar Cycloadditions. Past and FutureExtended version of lectures given at the Chemists' Meeting in Vienna (Austria) October 1961, and at the Gordon Research Conference, New Hampton (U.S.A.), 1961. (1963)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 2 (1963), S. 565-598 
    Details
    ISSN: 0570-0833
    Keywords: Dipolar cycloaddition ; Cycloaddition ; Heterocycles ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In contrast to the very large number of special methods applicable to syntheses in the heterocyclic series, relatively few general methods are available. The 1,3-dipolar addition offers a remarkably wide range of utility in the synthesis of five-membered heterocycles. Here the “1,3-dipole”, which can only be represented by zwitterionic octet resonance structures, combines in a cycloaddition with a multiple bond system - the “dipolarophile” - to form an uncharged five-membered ring. Although numerous individual examples of this reaction were known, some even back in the nineteenth century, fruitful development of this synthetic principle has been achieved only in recent years.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.196305651
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    Electronic Resource
    Electronic Resource
    Oligomers and Pleionomers of Synthetic Fiber-Forming Polymers (1963)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 2 (1963), S. 410-420 
    Details
    ISSN: 0570-0833
    Keywords: Oligomers ; Pleionomers ; Polymers ; Fibers ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The term “oligomer” is defined, and a survey of methods for the isolation and synthesis of cyclic and linear oligoesters, oligourethanes, oligo(acrylonitriles), and oligoamides is presented. The oligomers serve a valuable function as model substances for the investigation of many properties of the corresponding high polymers. This is shown using several examples (infrared spectroscopy, X-ray spectroscopy, viscosity).
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.196304101
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  • 20
    Electronic Resource
    Electronic Resource
    Pyrrolidone, Capryllactam and Laurolactam as new Monomers for Polyamide FibersFrom a lecture delivered at the meeting of the Plastics and Rubber Section of the Gesellschaft Deutscher Chemiker on April 9th, 1962, in Bad Nauheim (Germany). (1962)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 1 (1962), S. 430-435 
    Details
    ISSN: 0570-0833
    Keywords: Pyrrolidone ; Polyamides ; Fibers ; Lactams ; Polymerization ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The industrial production of capryllactam (1-azacyclononan-2-one) and of laurolactam (1-azacyclotridecan-2-one) starts with cyclization of acetylene or butadeine to give cyclooctatetraene or cyclooctadiene, or cyclization of butadiene to give cyclododecatriene. Further steps are: oxidation of the cyclic hydrocarbon to the ketone, formation of the oxime, and rearrangement of the latter with sulfuric acid. Pyrrolidone can be prepared from acetylene and formaldehyde by way of butyrolactone. The behavior of the lactams during polycondensation is described and the properties of the resulting fibers are compared with those of the known polyamide fibers.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.196204301
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  • 21
    Electronic Resource
    Electronic Resource
    β-Lactams, Their Polymerization and Use as Raw Materials for FibersFrom a lecture delivered on April 9th, 1962 at a meeting of the GDCh-Fachgruppe “Kunstsoffe and Kautschuk” Plastics and Rubber Division of the German Chemical Society in Bad Nauheim. (1962)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 1 (1962), S. 481-488 
    Details
    ISSN: 0570-0833
    Keywords: Lactams ; Polymerization ; Fibers ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: β-Lactams can be prepared by cyclization of β-aimno acid esters. Recently they have become available also from olefins by addition of N-carbonysulfamyl chloride (isocyanatosulfonyl chloride) and from aldehydes by reaction with N-carbonylsulfamyl chloride and ketene. Condensative or anionic polymerization results in polyamides the chains of which contain many more amide groups than the chains of polyamides of the nylon-6 type. Hence the new polymers resemble silk moreclosely. Fibers and films can be prepared from solution.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.196204811
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  • 22
    Electronic Resource
    Electronic Resource
    Dyeing of Poly(acrylonitrile) Fibers with Azatrimethinecyanines (1962)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 1 (1962), S. 532-537 
    Details
    ISSN: 0570-0833
    Keywords: Polyacrylonitrile ; Fibers ; Azatrimethinecyanines ; Dyes/Pigments ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Like all basic dyes, azatrimethinecyanines possess a good dyeing affinity for acrylic fibers. Compounds with isolated nitrogen atoms in the trimethine chain show insufficient light fastness, whereas good to excellent fastness to light is displayed by compounds having neighboring nitrogen atoms in the chain. Thus, a working hypothesis stating that the light fastness of trimethinecyanines on acrylic fibers is improved by progressive replacement of methine groups by nitrogen atoms has been partially confirmed.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.196205321
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  • 23
    Electronic Resource
    Electronic Resource
    Elastomeric Fibers Based on PolyurethanesFrom a report delivered on April 10th, 1962 at the meeting of the GDCh-Fachgruppe “Kunststoffe und Kautschuk” (Plastics and Rubber Group of the German Chemical Society) in Bad Nauheim. (1962)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 1 (1962), S. 419-424 
    Details
    ISSN: 0570-0833
    Keywords: Elastomers ; Fibers ; Polyurethanes ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Highly elastic polyurethanes suitable for fiber production can be obtained by various synthetic routes based on diisocyanate polyaddition processes. Macrodiisocyanates obtained from long chain diols and diisocyanates are allowed to react with polyamines during fiber formation (chemical spinning process) or the macrodiisocyanates are treated in solvents (e.g. dimethylformamide) with polyamines to give highly viscous, spinnable solutions of polymer. Both methods yield highly elastic polymers with wide-mesh network structures. The production of polyurethane fibers and their structures and physical properties are described.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.196204191
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    Electronic Resource
    Electronic Resource
    Copolymers and Fibers from VinylidenedicarbonitrileLecture at the Meeting of the Gesellschaft Deutscher Chemiker, Section “Kunststoffe und Kautschuk”, on April 10th. 1962 at Bad Nauheim (Germany). (1962)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 1 (1962), S. 425-430 
    Details
    ISSN: 0570-0833
    Keywords: Copolymers ; Fibers ; Vinylidenedicarbonitrile ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Vinyldendicarbonitrile (Vinylidene cyanide) on free redical catalyzed copolymerization shows a much stronger tendency to form 1:1 alternating copolymers than acrylonitrile. While bulk poly(vinylidene cyanide) fails to crystallize, despite its molecular symmetry, several alternating copolymers are readily crystallizable, notably those containing butadiene, isoprene, isobutylene, or vinylidene chloride. Fibers have been prepared from a number of the higher melting copolymers and examined for physical properties. Fibers from the vinyl acetate and vinyl chloride copolymers show expectional elastic behavior both when dry and wet. The fiber from the vinylidene cyanide |vinyl acetate alternating copolymer (Darvan® nytril fiber) is only moderately oriented and is characterized by exceptional softness and excellent elastic recovery and resilience, both when dry and wet.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.196204251
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  • 25
    Electronic Resource
    Electronic Resource
    Long Periods in Drawn PolyethyleneFrom a lecture delivered on Apr. 11th 1962 at the meeting of the GDCh-Fachgruppe “Kunststoffe und Kautschuk” (Plastics and Rubber Division of the German Chemical Society) in Bad Nauheim. (1962)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 1 (1962), S. 488-499 
    Details
    ISSN: 0570-0833
    Keywords: Long periods ; Polyethylene ; Fibers ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Meridional reflections appearing in small-angle X-ray diffraction diagrams of drawn polyethylene are caused by a nearly periodic arrangement of crystalline and disordered regions. The long period, which is determined by the average distance between two consecutive crystallites, depends on the method of preparing the sample. The time and temperature dependences of the positions of the small-angle reflections have been investigated. The growth of the long period of unoriented bulk polyethlene and polyethylene single crystal follows the same time dependence as that of stretched films. However, characteristic differences were obseved in the relationship between density and long period; they are attributed to the fact that in single crystals and in material crystallized from the melt, the chains are folded at the boundaries of the crystallites, whereas this in not the case in stretched polyethylene.
    Additional Material: 25 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.196204881
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