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  • 2000-2004  (21)
  • 1970-1974  (4,698)
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  • Inorganic Chemistry  (12,555)
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Material
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Year
Keywords
  • 101
    Electronic Resource
    Electronic Resource
    Effects of antibiotics on intracellular symbiotes in the pea aphid, Acyrthosiphon pisum (1974)
    Springer
    Cell & tissue research 148 (1974), S. 287-300 
    Details
    ISSN: 1432-0878
    Keywords: Symbiotes ; Aphids ; Antibiotics ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of penicillin and chlortetracyline HCl on the fine structure of the intracellular symbiotes of the pea aphid were studied in an attempt to remove the symbiote population. High penicillin concentrations, 1% and 0.1%, caused symbiote breakdown but were toxic and/or repellent to the aphids; at 0.1% specific effects were observed on the symbiotes' cell walls. After the use of 0.01% penicillin in the aphid diet, the symbiotes had abnormal cell walls and were abnormally dilated; however, symbiote division and transmission from one aphid generation to the next seemed unaffected and the aphids appeared normal. Aphids fed 0.1% chlortetracycline failed to reproduce. After 7 days, their symbiotes were found to break down at a high rate but aphid mitochondria were also adversely affected at this stage. Following 0.002% chlortetracycline, the aphids produced aposymbiotic progeny with apparently normal mitochondrial populations; these larvae failed to develop.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224257
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  • 102
    Electronic Resource
    Electronic Resource
    On the sexual segment of the kidney in the snake (Natrix natrix) (1974)
    Springer
    Cell & tissue research 148 (1974), S. 417-429 
    Details
    ISSN: 1432-0878
    Keywords: Kidney ; Sexual segment ; Natrix natrix ; Histochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The sexual segment of the kidney of Natrix natrix has been investigated cytochemically, light microscopically and ultrastructurally. The sexual segment, which seems to be an important accessory sexual organ, has a single layer of a columnar epithelium. The epithelial cells are filled with large secretion granules of a wide range of electron densities. Cytochemical reactions for neutral and acid mucosubstances are negative, but the cells show a strong positive staining for phospholipids. Within the cells of the sexual segment we have localised by histochemical means several hydrolases and oxydoreductases, which reflect enzyme activities of the glycolytic pathway, the citrate cycle, and related metabolic pathways. The activities of the hydrolytic enzymes acid phosphatase, acetylcholinesterase and indoxylacetate esterase are remarkably high within the epithelial cells. Furthermore it was found that the sexual segment tubules possess contractile elements which extends over the basal surface of the epithelial cells. These contractile cells exhibit a very high activity of alkaline phosphatase. Single unmyelinated axons are located between the contractile elements and the basal lamina of the sexual segment cells. The functional significance of the sexual segment structures is briefly discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224268
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  • 103
    Electronic Resource
    Electronic Resource
    Specific organization of intracytoplasmic filaments in the dog testicular interstitial cell (1974)
    Springer
    Cell & tissue research 148 (1974), S. 493-497 
    Details
    ISSN: 1432-0878
    Keywords: Testicular interstitial cells ; Dog ; Filaments ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the dog testicular interstitial cells the cytoplasmic filaments are occasionally arranged in large bundles piled closely in an extensive area adjacent to the Golgi region in the cytoplasm. Some of the large bundles show conspicuous circular or spiral configurations which are composed of elaborate arrangements of both circular and longitudinal filaments and accompany tubules of agranular endoplasmic reticulum running parallel to the longitudinal filaments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221933
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  • 104
    Electronic Resource
    Electronic Resource
    Rhombic dodecahedral secretory granules in glucagon producing islet cells (1974)
    Springer
    Cell & tissue research 148 (1974), S. 561-563 
    Details
    ISSN: 1432-0878
    Keywords: Pancreatic islets ; Xiphophorus helleri ; A2-Granules ; Crystalline structure ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary By tilting experiments in the electron microscope evidence was found for crystalline islet A2-granules of Xiphophorus helleri H. to be rhombic dodecahedral and thus to belong to the cubic system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221939
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  • 105
    Electronic Resource
    Electronic Resource
    Reconstitution of the thymus dependent area in the spleen of lethally irradiated mice (1974)
    Springer
    Cell & tissue research 149 (1974), S. 43-60 
    Details
    ISSN: 1432-0878
    Keywords: Spleen ; Thymus dependent area ; Periarteriolar lymphatic sheath (PALS) ; Interdigitating cell (IDC) ; T-lymphocyte ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary To study the submicroscopical morphology of the microenvironment for T-lymphocytes in the spleen, mice were lethally X-irradiated and injected intravenously with syngeneic thymocytes. 24 hours after cell transfer, small lymphocytes occurred in the thymus dependent area of the spleen: the periarteriolar lymphatic sheath (PALS). They localized preferentially around a special type of mononuclear phagocyte, the Interdigitating Cell (IDC), which is considered to be characteristic for thymus-dependent areas in peripheral lymphoid organs. A close cell contact between both cell types was observed: small lymphocytes protruded into the cytoplasm of the IDC by means of fingerlike protrusions. This type of cell contact seems to induce blast transformation of the lymphoid cells which resulted in the formation of medium sized T-cells. In a control experiment, spleen cells from thymectomized, X-irradiated and bone marrow reconstituted mice were injected intravenously into lethally X-irradiated recipients. These B-lymphocytes, however, were not found to be localized around IDC. They preferentially formed primary follicles at the periphery of lymphocyte-depleted thymus dependent areas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00209049
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  • 106
    Electronic Resource
    Electronic Resource
    Altered formation of dye-induced lysosomes in mouse fibroblasts due to growth in “deficient” media (1974)
    Springer
    Cell & tissue research 147 (1974), S. 219-235 
    Details
    ISSN: 1432-0878
    Keywords: Lysosomes ; Mouse fibroblasts ; Dye treatment ; Cell culture ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Mouse fibroblasts were grown in a ‘deficient’ medium consisting solely of Hank's salt solution. Treatment of cells after 48 hours in deficient medium with the cationic dye, mepacrine, resulted in an altered formation of lysosomes. Cells grown in full medium form dense, multi-vesiculated lysosomes in response to mepacrine. Cells grown in deficient medium form large electron lucent vacuoles containing peripherally located dense globules. The significance of the observations in relation to the deficiency of the medium is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00582797
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  • 107
    Electronic Resource
    Electronic Resource
    Investigations of ageing in costal and tracheal cartilage of rats (1974)
    Springer
    Cell & tissue research 147 (1974), S. 505-527 
    Details
    ISSN: 1432-0878
    Keywords: Cartilage ; Ageing ; Chondrocyte and matrix ; Light microscopy ; Histochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Histological, histochemical, and ultrastructural investigations have been carried out on ageing costal and tracheal cartilage of rats. The following age groups of animals have been studied: 1, 7, 14, 20, 30, 45, 75 days, 6 months, and 2 years. Ageing induces cellular changes which are represented by a reduction in the number of chondrocytes, a progressive increase in glycogen deposition, and processes of degeneration, the most frequent of which is the accumulation of lipidic material within large cytoplasmic vacuoles. Changes in the intercellular matrix become evident after 20 days in costal cartilage and after 30 days in tracheal cartilage. Chondroitin sulphate decreases while keratan sulphate, whose presence is limited to the territorial matrix, increases. Glycoproteins increase slightly in young animals and then remain constant; they decrease in the subperichondrial areas in old animals. Ultrastructurally, the matrix of cartilage of young animals contains thin collagen fibrils, most of which have no periodic banding. Roundish electron dense granules are associated with these fibrils. Irregular filaments associated with small electron-dense circular bodies are present around chondrocytes as well as within cytoplasmic vacuoles. With increasing age, and coincident with the reduction of chondroitin sulphate, the thickness of collagen fibrils increases, their period becomes evident, and the associated matrix granules decrease in number and size. Areas containing these fibrils undergo calcification, which frequently starts within roundish bodies of cellular origin. Collagen fibrils with a period of 640 Å but a highly variable thickness are often present in cartilage of adult and old rats. These fibrils seem to be due to an abnormal synthetic activity of chondrocytes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307252
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  • 108
    Electronic Resource
    Electronic Resource
    A quantitative morphological analysis of macrophage stimulation (1974)
    Springer
    Cell & tissue research 147 (1974), S. 567-588 
    Details
    ISSN: 1432-0878
    Keywords: Macrophage ; Freund's adjuvants ; Stimulation ; Stereology ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The principles of stereology have been applied to a stereometric analysis of the ultrastructural composition of normal rat peritoneal macrophages and of cells stimulated five days previously by a single intraperitoneal dose of Freund's adjuvants. Material obtained by a systematic random sampling regime was analysed and the data groups for various morphological parameters were compared. Estimates were made of cell numbers. From electron micrographs the volume proportions of nuclei, mitochondria, heterogeneous granules and rough endoplasmic reticulum were determined. The average numbers and dimensions of mitochondria, granules and free ribosomes were also evaluated. The volume-to-surface ratios of cells and their nuclei were computed. By the independent measurement of cellular volumes it was possible to obtain estimates of nuclear and cytoplasmic volumes, to evaluate the membrane surface areas of the average cells and their nuclei, and to calculate numbers of organelles per average cell. The structural alterations induced by the complete adjuvant were similar to those evoked by the incomplete adjuvant. Stimulation was characterized by a cellular hypertrophy accompanied by an increase in mean granule size and in the number of mitochondria per average cell. At the same time, there was a substantial decrease in the number of granules and a considerable depletion of both nuclear and plasma membrane surface areas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307256
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  • 109
    Electronic Resource
    Electronic Resource
    Electron microscope studies on the intestine using ruthenium red (1974)
    Springer
    Cell & tissue research 147 (1974), S. 271-283 
    Details
    ISSN: 1432-0878
    Keywords: Intestinum ; Diseases of the colon ; Laboratory animals ; Ruthenium red ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Ruthenium-Rot gefärbte Darmpräparate verschiedener Krankheitsbilder sowie verschiedener Laboratoriumstiere wurden elektronenmikroskopisch untersucht. Ruthenium-Rot läßt sich im Bereich des Intestinaltraktes teils homogen, teils grob- und feingranulär nachweisen. Microvilli and Glycokalyx sind relativ konstant Ruthenium-Rot gefärbt. Der Intercellularraum der Lamina epithelialis mucosae zeigt eine auffallend variable Ruthenium-Rot Anfärbung. Diese ist offenbar nicht methodisch bedingt, sondern Ausdruck eines unterschiedlichen bzw. variablen Funktionszustandes. Es bleibt offen, ob Ruthenium-Rot im Sinne einer histochemischen Reaktion bestimmte, im interzellulären Raum gelegene Substanzen markiert, oder als Tracer für den Stofftransport angesehen werden muß. Becherzellen und nekrobiotische Zellen weisen in der Regel eine konstante Ruthenium-Rot Anfärbung auf. Im Stratum proprium mucosae ist der Reaktionsausfall für Ruthenium-Rot sehr inkonstant, möglicherweise auf Grund des langen Penetrationsweges. Ziemlich regelmäßig findet sich allerdings eine Ruthenium-Rot Markierung de Phagolysosomen von Makrophagen. Prinzipielle Unterschiede der explorierten Gewebe und Tierarten bezüglich der Affinität zu Ruthenium-Rot bestehen nicht.
    Notes: Summary Biopsy specimens of human intestines in various disease states and from laboratory animal intestines have been stained with ruthenium red and inspected by electron microscopy. Ruthenium red reaction product is found as a homogeneous deposit and also in the form of coarse and fine granules. Microvilli and the glycocalyx are stained relatively constant by ruthenium red. The intercellular space of the epithelium shows a strikingly variable ruthenium red staining. This variation is apparently not related to the method but indicates differences or variations in the functional state of the membranes. It remains an open question whether the ruthenium red reaction is a histochemical reaction, marking certain substances present in in the intercellular area or whether it should be considered as a tracer for the transport of materials. Goblet cells and necrobiotic cells usually show a constant ruthenium red staining. In the lamina propria the reaction product is very inconstant, possibly on account of the long penetration path from the lumen. The phagolysosomes of macrophages are marked by ruthenium red rather regularly. No fundamental, but only quantitative differences have been found between the various kinds of tissue studied.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00582801
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  • 110
    Electronic Resource
    Electronic Resource
    The surface film on the mesothelium of the serous membranes of the rat (1974)
    Springer
    Cell & tissue research 147 (1974), S. 595-597 
    Details
    ISSN: 1432-0878
    Keywords: Mesothelium (rat) ; Surface film ; Ruthenium red ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A surface film with a thickness of 280–570 Å covers the mesothelium of serous membranes in the rat. This film can be stained with ruthenium red. Its considerable water-binding capacity produces the reflecting surface of the serous membranes. The friction of the organs is thereby greatly reduced. Only a small amount of serous fluid must be produced to keep the surface moist. The glucosamino glycans of the surface film are probably synthesized by the mesothelial cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307258
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  • 111
    Electronic Resource
    Electronic Resource
    Ovulation and the mechanism of follicle rupture (1974)
    Springer
    Cell & tissue research 149 (1974), S. 313-327 
    Details
    ISSN: 1432-0878
    Keywords: Follicle rupture ; Rabbit ; Ovary surface epithelium ; Induced ovulation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary To elucidate the intra-ovarian mechanism of follicle rupture, young, sexually mature rabbits were oophorectomized at accurately determined times after an ovulatory dose of human chorionic gonadotrophin (HCG), and the surface epithelium of Graafian follicles was studied by transmission electron microscopy. At 4 hr after injection of HCG the surface epithelial cells are considerably larger than earlier and many of them show large, round, dense, cytoplasmic bodies, particularly in the apical region of the preovulatory follicles. Up to 8 hr after injection of HCG there is a gradual accumulation of the large, dense bodies; from then on they markedly decrease in amount. Recently reported values of prostaglandins in rabbit Graafian follicles at various times after ovulatory stimulation and of steroid hormone levels in the Graafian follicle and the ovarian vein have been correlated with the ultrastructural changes. Both sex steroids and prostaglandins can labilize lysosomal membranes (and presumably other membranes as well) and may thus cause leakage of lytic enzymes. The large dense bodies of the apical surface epithelium of preovulatory follicles may represent an important source of (lysosomal) enzymes to effect weakening of the follicle wall and rupture of the follicle apex in a fairly constant area, the stigma.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00226766
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  • 112
    Electronic Resource
    Electronic Resource
    An ultrastructural study of the spermatids of Campodea C. remyi Denis (Diplura Campodeidea) at the bundle stage (1974)
    Springer
    Cell & tissue research 149 (1974), S. 555-566 
    Details
    ISSN: 1432-0878
    Keywords: Spermatogenesis ; Spermatid ; Campodea (apterygota) ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé A un certain stade de leur évolution, les spermatides de Campodea C. remyi Denis sont réunies en petites touffes de 236 á 650 éléments. Leurs acrosomes sont implantés dans une substance homogéne (ciment) assez dense aux électrons. La spermatide comprend une région acrosomienne et une région postacrosomienne où sont alignés parallèlement: l'axonème, les deux dérivés mitochondriaux et le noyau. L'acrosome est assez long, il est renforcé par 7 à 10 microtubules. L'axonème est du type 9+9+2; les mitochondries sont de longueur presque égale. Le noyau plus court, montre une chromatine très dense aux électrons. Au niveau de la région postérieure du noyau, la membrane cytoplasmique se replie sur elle-même pour former une sorte de collerette ouverte vers l'arrière. En région distale de la spermatide, on observe au niveau d'un élargissement, une superposition de structures lamellaires.
    Notes: Summary The spermatids of Campodea C. remyi Denis are clumped in small bundles of 236 to 650 elements during spermiogenesis, their acrosomes being embedded within an homogeneous electron dense material. The spermatid comprises an acrosomal region and a postacrosomal region within which, the two mitochondrial derivatives and the nucleus are arranged in parallel. The acrosome is rather long, it is reinforced by seven to ten microtubules. The axoneme is of the 9+9+ pattern. The mitochondria are of almost equal length. The shorter nucleus shows a very electron dense chromatin. At mid-nuclear level the cytoplasmic membrane is folded up to form a sort of collar opening backwards. Distal to the nucleus, superimposed lamellar structures are found located in an expanded part of the spermatid.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00223032
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  • 113
    Electronic Resource
    Electronic Resource
    Pycnogonid sperm. An example of inter- and intraspecific axonemal variation (1974)
    Springer
    Cell & tissue research 149 (1974), S. 105-111 
    Details
    ISSN: 1432-0878
    Keywords: Sperm flagella ; Motility ; Axonemal variation ; Axonemal evolution ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The flagella of the motile sperm cells of Nymphon leptocheles and N. rubrum (Pyonogonida, Arthropoda) exhibit a 12+0 and a 9+0 axoneme pattern, respectively. Central tubules, central sheath, spokes and arms are absent. The doublets are connected by a circular nexus. The functional significance of this axonemal composition is discussed. Aberrant axonemes occurring in high frequencies both within the species and within single specimens are probably explained by the loose axonemal connection, due to the absence of a central complex. This absence is further suggested to have facilitated the evolution from the 9+0 type to the 12+0 type.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00209053
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  • 114
    Electronic Resource
    Electronic Resource
    The fine structure of adrenal zona glomerulosa in the adult rat (1974)
    Springer
    Cell & tissue research 149 (1974), S. 235-243 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal zona glomerulosa ; Rat ; Normal ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary This paper reports on an electron microscopic study of the adrenal zona glomerulosa in the normal rat, with special emphasis on the structural diversity of mitochondria in its parenchymatous cells. The mitochondria of cristae may be tubulo-vesicular, plate-like and/or straight tubular, any one mitochondrion containing one or more types of cristae. The mitochondrial features of the zona glomerulosa parenchymatous cells are attributed to the biochemical stages of aldosterone synthesis, taking place in different mitochondria of these cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00222276
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  • 115
    Electronic Resource
    Electronic Resource
    Intracisternal inclusions in nerve cells of cat ventromedial hypothalamic nucleus (1974)
    Springer
    Cell & tissue research 149 (1974), S. 283-286 
    Details
    ISSN: 1432-0878
    Keywords: Intracisternal inclusions ; Nerve cells ; Ventromedial hypothalamic nucleus (Cat) ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Peculiar inclusions occur within cisternae of the granular endoplasmic reticulum of some perikarya of the ventromedial hypothalamic nucleus in cats. These inclusions appear as rods or bullet-shaped structures and their interiors are generally less dense. The inclusions may represent virus particles or proteinaceous products of the granular endoplasmic reticulum in which protein-synthetizing activities are probably increased to enormous extents.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00222280
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  • 116
    Electronic Resource
    Electronic Resource
    Lipidosis-like alterations in hypothalamic neurosecretory cells of rats treated with chlorphentermine or iprindole (1974)
    Springer
    Cell & tissue research 149 (1974), S. 587-590 
    Details
    ISSN: 1432-0878
    Keywords: Chlorphentermine ; Iprindole ; Nucl.supraopticus ; Nucl.paraventricularis ; Lipidosis, drug-induced ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Prolonged administration of the anorectic drug chlorphentermine or of the antidepressant agent iprindole to rats caused the formation of lamellated and crystalloid inclusions in neurosecretory cells of supraoptic and paraventricular nuclei of the rat hypothalamus The observations are interpreted as supporting the concept of a generalized phospholipidosis inducible by compounds of amphiphilic character.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00223035
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  • 117
    Electronic Resource
    Electronic Resource
    Investigations on the fine structure of purkinje fibres in the atrium of the avian heart (1974)
    Springer
    Cell & tissue research 150 (1974), S. 43-56 
    Details
    ISSN: 1432-0878
    Keywords: Purkinje fibres ; Avian heart ; Fine structure ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The subendocardial Purkinje fibres in the right atrium of the heart of the adult fowl were investigated by light and electron microscopy. The myofibrils often originate from the lateral cell membrane of the cells and show a spirally wound course. Their arrangement is obviously not random. In some Purkinje cells the absolute amount of myofibrils per cell is as large as in ordinary myocardial muscle cells. The sarcoplasmic reticulum is constituted by ramifying tubules. They are distributed throughout the entire Purkinje cell and contact the myofibrils, the mitochondria, and the cell membrane. At the cell membrane the sarcoplasmic reticulum forms terminal cisternae, which often possess an electron dense content. These terminal cisternae are apparently unrelated to the Z-discs of the myofibrils. The cytoplasmic organelles of the Purkinje cell are embedded in a network of ca. 100 Å thick filaments. It is assumed that these filaments are responsible for the maintenance of the arrangement of the cell organelles. Some Z-discs of the myofibrils of the Purkinje cells are up to 0.4 μm long. Axon terminals running between the Purkinje fibre and the fibrocytic envelope may lie only 150 Å from the fibrocytes. The fibrocytes are connected by tight junctions and desmosomes and contain fine filaments and microtubules. The possible implications of these findings are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220379
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  • 118
    Electronic Resource
    Electronic Resource
    The ultrastructure of binucleate keratinocytes and binucleation in palatal mucosa of guinea pigs (1974)
    Springer
    Cell & tissue research 150 (1974), S. 113-123 
    Details
    ISSN: 1432-0878
    Keywords: Binucleation ; Amitotic nuclear division ; Palatal epithelium (Guinea pig) ; Keratinocytes ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The palatal epithelium of adult male guinea pigs contains a considerable number of binucleate epithelial cells in all strata but the basal cell layer. Electron microscopical examination shows that the two equal-sized nuclei are dome-shaped with the flattened surfaces closely approximated, the distance between the nuclei being 30 nm or more. No points of contact have been found between the nuclear membranes. No differences in number, distribution or ultrastructure of cytoplasmic organelles were found between mono- and binucleate epithelial cells. Evidence of amitotic nuclear division being a plausible mechanism of binucleation is presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220385
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  • 119
    Electronic Resource
    Electronic Resource
    The distribution of noradrenergic nerves and small, intensely fluorescent (SIF) cells in the cat urinary bladder (1974)
    Springer
    Cell & tissue research 150 (1974), S. 147-159 
    Details
    ISSN: 1432-0878
    Keywords: Urinary bladder ; Autonomic innervation ; SIF cells ; Fluorescence ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Fluorescence and electron microscopy have been used to study the distribution of noradrenergic nerves in the smooth muscle of the cat urinary bladder. Using the former technique, relatively few fluorescent noradrenergic nerves were observed in the body and fundus, while a rich plexus occurred adjacent to muscle cells of the bladder neck. The trigone could not be distinguished neuromorphologically from detrusor muscle in this region. Electron microscopy showed that the majority of noradrenergic terminals in the body and fundus were associated with presumptive cholinergic axons, while in the bladder neck noradrenergic terminals formed typical neuroeffector relationships with individual smooth muscle cells. Numerous ganglia occurred both in the adventitia and among the smooth muscle bundles, particularly in the bladder neck. The majority of the nerve cell bodies were non-fluorescent, although many contained bright orange autofluorescent granules, believed to be lysosomes. A small minority of ganglion cells were associated with fluorescent noradrenergic nerve terminals, thereby providing structural evidence for limited intraganglionic inhibition. In addition, occasional groups of small intensely fluorescent (SIF) cells were observed in some intramural ganglia and these were subsequently identified in the electron microscope. The possibility that these cells may provide a second inhibitory influence on bladder activity was considered.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00222166
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  • 120
    Electronic Resource
    Electronic Resource
    The sarcolemma of skeletal muscle fibres as demonstrated by a replica technique (1974)
    Springer
    Cell & tissue research 150 (1974), S. 377-387 
    Details
    ISSN: 1432-0878
    Keywords: Sarcolemma ; Collagen texture ; Frog ; Electron microscopy ; Replica technique
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Single stage carbon replicas were obtained from dried bundles of frog skeletal muscle fibres at different sarcomere lengths. In unfixed specimens finer details are masked by an amorphous substance; after fixation with glutaraldehyde a network of collagen fibrils covering the muscle fibres appears. At a sarcomere length of 1.8 μm the collagen fibrils are oriented diagonally and transversely; between a sarcomere length of 2.8 and 3.1 μm the collagen fibrils are increasingly oriented along the axis of the muscle fibre. This indicates a helical arrangement of the collagen fibrils in the sarcolemma, the pitch being grossly related to sarcomere length. Collagen fibrils and fibres in the endomysium are not oriented according to sarcomere length; hence at low degrees of stretch, force applied to the tendon is primarily transmitted by the muscle fibres and not by the endomysium. Replicas from skinned fibres showed that shrinkage is most pronounced in the I-bands and least in the Z-and M-lines.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220144
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    The acrosome reaction in the sperm of the shipworm Bankia australis calman (Bivalvia, Mollusca) (1974)
    Springer
    Cell & tissue research 151 (1974), S. 93-101 
    Details
    ISSN: 1432-0878
    Keywords: Acrosome reaction ; Bankia australis ; Teredo ; Fertilization ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the acrosome reaction in the sperm of the teredo, Bankia australis, is described. In brief, the reaction consists of three phases: (a) formation of a bleb and membrane fusion, (b) disappearance of the longitudinally oriented fibrils, and (c) outward flaring and disappearance of the osmiophilic granule. The osmiophilic granule appears to consist of prism-like structures. The axial rod never lengthens during the acrosome reaction.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00222037
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  • 122
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    Similarities between Hassall's corpuscles of the human thymus and the epidermis (1974)
    Springer
    Cell & tissue research 151 (1974), S. 347-368 
    Details
    ISSN: 1432-0878
    Keywords: Human thymus ; Hassall's corpuscles ; Histochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Substrate-histochemical, enzyme-hystochemical and ultrastructural investigations were performed on thymic tissue from children, obtained in heart operations. β-Amylaseresistant, PAS-positive and Hale-positive substrates presumably neutral and acid mucosubstances, can be demonstrated in the central concentric lamellae of Hassall's corpuscles (HC). These lamellae also give positive reactions for sulphydryl groups and disulphide groups. Some flattened cell elements gave strong reactions for phospholipids, and small sudanophilic droplets, presumably neutral fats, are scattered throughout the HC. All investigated hydrolases and dehydrogenases either give no or only very weak reactions in the central part of progressive HC, but react strongly positive in their peripheral hypertrophic epithelial cells. In the central part of regressive HC, positive reactions for acid phosphatase and β-D-glucuronidase were recognized. These lysosomal enzymes may indicate degenerative processes. By electron microscopy progressive HC show central concentric lamellae with an amorphous matrix tightly filled with tonofilaments. They are surrounded by a thickened plasma membrane (200 Å), and do not contain nuclei. These central lamellae resemble the horny cells of the epidermis. The peripheral hypertrophic epithelial cells have pale nuclei with one or two nucleoli. Their cytoplasm contains numerous tonofibrils. These cells resemble stratum spinosum cells of the epidermis. In regressive HC the central concentric lamellae loose their intercellular contacts. The widened intercellular spaces are filled with cellular debris, and are invaded by macrophages. Similarities between the ultrastructure and the patterns of the histochemically investigated substrates and enzymes in human HC and epidermis are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224546
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  • 123
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    Studies on the juxtaglomerular apparatus (1974)
    Springer
    Cell & tissue research 151 (1974), S. 471-480 
    Details
    ISSN: 1432-0878
    Keywords: Juxtaglomerular apparatus ; Rat ; Influence of deoxycorticosterone (DOC) ; Electron microscopy ; Morphometric analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die quantitativ-morphologische Analyse des juxtaglomerulären Apparates nach DOC-Behandlung zeigte, daß mit der Hemmung der Reninbildung eine Hypoplasie der epitheloiden Zellen des juxtaglomerulären Apparates einhergeht. Der Granulagehalt der juxtaglomerulären Zellen nahm ab; die Kern-Plasma-Relation änderte sich und die Leiomyofibrillen in den Epitheloidzellen nahmen zu. An den übrigen Anteilen des juxtaglomerulären Apparates, insbesondere der Macula densa, wurden keine morphologischen Veränderungen beobachtet. Die DOC-Behandlung führte darüber hinaus zu einer Bildung von Einschlüssen in den Podocyten, den Mesangiumzellen und den Zellen der Bowman-Membran. Die verschiedenen Möglichkeiten, über welche Faktoren die juxtaglomerulären Zellen nach DOC-Behandlung degranuliert werden, werden diskutiert. Das ultrastrukturelle Bild der Epitheloidzellen nach DOC-Behandlung entspricht deutlich einer gehemmten Sekretion, da das Ergastoplasma und der Golgi-Apparat ganz besonders stark zurückgebildet werden.
    Notes: Summary Quantitative morphological analysis of the Juxtaglomerular apparatus of rats treated with deoxycorticosterone (DOC) and salt revealed hypoplasia of the epithelioid cells as a concomitant of the inhibition of renin synthesis. The granular content of the Juxtaglomerular cells was significantly decreased, while the nucleus-to-cytoplasm ratio and the volume density of leiomyofilaments in the epithelioid cells increased. No morphological alterations were observed in the remaining constituents of the Juxtaglomerular apparatus, including the macula densa. DOC-treatment also induced the appearance of inclusions in the podocytes in the cells of the mesangium, and in the cells of Bowman's capsule. The possible mechanisms of degranulation of the Juxtaglomerular cells after treatment with DOC are discussed. The ultrastructural appearance of the epithelioid cells after treatment with DOC corresponds to an inhibition of secretion, since the rough endoplasmic reticulum and the Golgi apparatus undergo marked regressive changes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00222992
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  • 124
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    The reaggregation of neurons and their satellite cells in cultures of trypsin-dissociated spinal ganglia (1974)
    Springer
    Cell & tissue research 152 (1974), S. 175-183 
    Details
    ISSN: 1432-0878
    Keywords: Cell aggregation ; Spinal ganglia ; Cell cultures ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Dorsal root spinal ganglia of chick embryos were trypsinized and the cellular components isolated. Suspensions of these cells reaggregate. During this process satellite glial cells and neurons established intimate contacts. The reconstructed glial envelopes around the neurons are morphologically similar to the ones formed in the intact animal during development. The formation of the characteristic glial-neuronal relation is an example of specific cell recognition.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224693
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  • 125
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    The interaction of phagocytes and the large-sized parasite Cryptococcus neoformans: Cytochemical and ultrastructural study (1974)
    Springer
    Cell & tissue research 152 (1974), S. 165-174 
    Details
    ISSN: 1432-0878
    Keywords: Phagocytosis ; Large foreign bodies ; Cryptococcus neoformans ; Tissue culture ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The yeast Cryptococcus neoformans may develop under certain conditions a large polysaccharide capsule 50–100 μM in diameter and therefore cannot be phagocytosed by either polymorphonuclear cells (PMN's) or mononuclear phagocytes (MN's). The cellular defense mechanism — in various animals — against the yeast is composed by formation of ringlike structure of PMN's or MN's cells which surround the C. neoformans. Ring structures develop either in vivo or in vitro in tissue culture; destruction of the yeast occurs within 36–72 hours. Several hydrolases, such as acid phosphatase, β-glucuronidase and non-specific esterase were found to be released from the phagocytic cells into the enclosed yeast. Considerable reduction of NBT used as a marker for oxidative activity was observed in MN rings at contact regions of the MN cells and the yeast. Electron microscopic studies indicate that the phagocytic cells in the ring structure have many pseudopodes penetrating into the polysaccharide capsule of the yeast. Disintegration of the capsule was observed as well as phagocytosis of its material. A possible analogy between normal phagocytosis of small-sized bodies and the ring structure obtained when large bodies are involved is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224692
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  • 126
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    Involution of the caudal musculature during metamorphosis in the ascidian, Botryllus schlosseri (1974)
    Springer
    Cell & tissue research 153 (1974), S. 293-305 
    Details
    ISSN: 1432-0878
    Keywords: Ascidia (Botryllus schlosseri) ; Metamorphosis ; Muscle tissue involution ; Phagocytes ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The caudal musculature of the free-swimming tadpole of the ascidian, B. schlosseri consists of cylindrical mononucleated cells connected in longitudinal rows flanking the axial notochord. During resorption of the larval tail, which is apparently induced by the contraction of the epidermis, muscle cells are dissociated and pushed into the body cavity where most of them are rapidly engulfed by phagocytes. In the initial stages of tail withdrawal muscle cells display surface alterations due to the disruption of intercellular junctions and disarrangement of myofibrils. Extensive degenerative changes, with shrinkage of mitochondria and disintegration of the contractile material are subsequently observed. Lysosomes and autophagic vacuoles are rarely seen and appear to play a secondary role in the degradation of the muscle cells, which occurs predominantly within the phagocytes. Myofilaments and myofibrils have never been observed within autophagic vacuoles. Clumps of muscle fragments and degenerated phagocytes undergo eventual dissolution in the blood lacunae, concomitantly with the differentiation of the young oozooid.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00229160
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  • 127
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    Adhesion plaques associated with the production of a daughter cell in Euglypha (Testacea; Potozoa) (1974)
    Springer
    Cell & tissue research 153 (1974), S. 261-268 
    Details
    ISSN: 1432-0878
    Keywords: Amoebae (Testacea) ; Siliceous plates ; Production ; Role of microtubules in fission ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Euglypha acanthophora and Euglypha strigosa, testate amoebae with siliceous shells, undergo binary fission producing daughter cells. The siliceous plates from which the shells are constructed are produced in the Golgi and perinuclear regions of the parent. At binary fission these pass along microtubule pathways and are manoeuvered into position in the daughter-cell by microtubule (20–25 nm) and microfilament (7–9 nm) systems. The latter in the form of adhesion plaques are instrumental in the coordination and deployment of the shell-plates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00226614
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  • 128
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    Transformations of hypothalamic arcuate neurons (1974)
    Springer
    Cell & tissue research 153 (1974), S. 497-515 
    Details
    ISSN: 1432-0878
    Keywords: Arcuate nucleus ; Hypothalamus ; Sexual cycle ; Ribbon-rolls ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Changes in subcellular structures of arcuate neurons correlated in a consistent way with stages of the estrous cycle of the rat. Associated with the rough endoplasmic reticulum short ribbons of moderately electron dense material appeared at metestrus and circular or elliptical bodies termed “ribbon-rolls” at diestrus and proestrus. Although present in proestrus, the ribbon-rolls were smaller at this stage. In a few neurons in diestrous females and in ovariectomized animals one to seven months before perfusion multiple large ribbon-rolls occupied much of the cytoplasm. Also, frequency of dense granules and lysosomes increased in diestrus. The significance of the ribbon-rolls and changes in other structures during the estrous cycle are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00231543
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  • 129
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    The ventricular system in neuroendocrine mechanisms (1974)
    Springer
    Cell & tissue research 154 (1974), S. 1-16 
    Details
    ISSN: 1432-0878
    Keywords: Ventricle ; Tanycytes ; Monoamine transport ; Autoradiography ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary This investigation has dealt with a light and electron microscopic autoradiographic analysis of the median eminence of the rat following intraventricular infusion of 3H-dopamine. This study has demonstrated that 3H-dopamine, once infused into the mammalian cerebral ventricular system, is rapidly and selectively absorbed by tanycytes and transported to the contact zone within 5 minutes after ventricular infusion. Certain axon terminals in the ependymal, hypendymal, and palisade-contact zones selectively sequester 3H-dopamine as do subpopulations of arcuate neurons. This picture of intense labelling of neurons and axon terminals is discussed with respect to monoaminergic re-uptake mechanisms. Uptake and transport of 3H-DA by tanycytes is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221067
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  • 130
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    A new membrane organelle in developing amphibian neurones (1974)
    Springer
    Cell & tissue research 154 (1974), S. 103-108 
    Details
    ISSN: 1432-0878
    Keywords: Plasma membrane specialisations ; Developing neurons ; Xenopus laevis ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Membrane specialisations have been found on neurones in embryos of the clawed toad Xenopus laevis. The specialisations have been called dense membrane knobs and consist of an outpushing of the plasma membrane with a slight increase in its density. The out-pushing forms a spherical knob with an amorphous dense core and a total diameter of 500 to 600 Å. The knobs are found on axons and dendrites both in the spinal cord and peripherally.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221074
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  • 131
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    Gap junctions in the heart of teleost fish (1974)
    Springer
    Cell & tissue research 154 (1974), S. 131-134 
    Details
    ISSN: 1432-0878
    Keywords: Heart musculature ; Teleost ; Gap junctions ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary An examination of cell contacts was made in the atrial and ventricular muscle of Teleost fish. The intercalated discs consist of two types of junction resembling fascia and macula adherens. Small focal areas of gap junctions were shown to be numerous away from the regions of intercalated disc between the myocardial cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221077
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  • 132
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    Ultrastructure of the neurosecretory system of the Colorado potato beetle, Leptinotarsa decemlineata (Say) (1974)
    Springer
    Cell & tissue research 154 (1974), S. 275-288 
    Details
    ISSN: 1432-0878
    Keywords: Neurosecretion ; Insect ; Leptinotarsa decemlineata ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of seven types of neurosecretory cells (NSC) in the medial and lateral groups of the protocerebrum is described. The differences among cell types established earlier by light microscopy parallel differences in size and appearance of the neurosecretory particles observed in electron micrographs. No relationship was found between the affinity for Gomori's paraldehyde fuchsin stain and the nature of the particles. The secretions of the A-, A1-, and C-types of NSC of the medial group are characterized by electron-dense neurosecretory granules of 1250 Å dia., medium-dense granules of 2100 Å, and electron-lucent vesicles of 1700 Å, respectively. The L-type NSCof the lateral group contain smaller (1300 Å) or larger (1700 Å) neurosecretory granules. The medial B- and E-types of NSC and the lateral LB-type contain granulated vesicles (1200 Å) of the same appearance. These cell types differ in other respects and most likely have separate functions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00223726
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  • 133
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    Myofibroblasts in the rat testicular capsule (1974)
    Springer
    Cell & tissue research 154 (1974), S. 533-541 
    Details
    ISSN: 1432-0878
    Keywords: Myofibroblasts ; Testicular capsule (rat) ; Connective tissue ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A specialized type of fibroblast occurs in the testicular capsule of adult rats. The flattened cells are characterized by bundles of cytoplasmic filaments. Filament bundles run parallel to the cell surface and insert in plaques of granular, electron dense material which is attached to the inner surface of the plasma membrane (attachment zones). Cytoplasmic filaments measure 60–80 Å in diameter. Sporadically plaques of basal lamina-like material are found, especially in the region of attachment zones. These specialized fibroblasts are interpreted as myofibroblasts. It is supposed that contractility of the testicular capsule in rats is caused by myofibroblasts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219672
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  • 134
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    The ultrastructure of the sinus gland of Carcinus maenas (Crustacea: Decapoda) (1974)
    Springer
    Cell & tissue research 155 (1974), S. 117-125 
    Details
    ISSN: 1432-0878
    Keywords: Sinus gland ; Carcinus maenas (Crustacea, Decapoda) ; Nerve fibre cell types ; Neurosecretion ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The sinus gland of Carcinus maenas consists of the swollen axonal endings of the neurosecretory cells of the major ganglia and acts as a storage release centre for the membrane bound neurosecretory material. These neurosecretory granules fall into five different types based on size and electron density. Their contents are released by exocytosis of the primary granules or smaller units budded from the primary granules.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220288
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  • 135
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    Fine structural and enzyme histochemical observations on the dorsal tail tubercle of Mertensiella caucasica (Urodela, Amphibia) (1974)
    Springer
    Cell & tissue research 156 (1974), S. 103-112 
    Details
    ISSN: 1432-0878
    Keywords: Dorsal tail tubercle ; Urodela ; Skin ; Hedonic glands ; Electron microscopy ; Enzyme histochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Dorsal tubercle and skin of Mertensiella caucasica have been investigated with the electron microscope and enzyme histochemical methods. The epidermis of the tubercle consists of 8–9 cell layers, that of normal dorsal skin of 5–6. The tubercle is filled with large mucous glands which are surrounded by an almost complete layer of smooth muscle cells (myoepithelial cells). Their glandular cells undergo cyclical changes and are characterized by specific secretory granules, which differ from those of the relatively small mucous glands of the normal dorsal skin. In the connective tissue of the tubercle a relatively rich supply of nerve fibres has been found, which in part contain synaptic and dense core vesicles or accumulations of mitochondria. In the normal dorsal skin nerve fibres occur less frequently. The following enzymes have been demonstrated in the mucous glands of the tubercle: SDH, acid phosphatase, unspecific esterases, E 600 resistant esterase. The tubercle seems to stimulate the female cloaca chemically and mechanically.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220104
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  • 136
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    Photoelektronenspektren und Moleküleigenschaften, XXVI. Die Delokalisation von Schwefel-Elektronenpaaren in Alkylsulfiden und -disulfiden (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 68-77 
    Details
    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
    URL: http://dx.doi.org/10.1002/cber.19741070109
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    Ylid-Komplexe von Nickel-alkylen (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 93-101 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Nickelalkyl Ylid ComplexesFrom reactions of [(CH3)3P]3 Ni(CH3)2 and [(CH3)3P]2Ni(CH3)Cl with the ylid (CH3)3PCH2, molecular (1) an ionic complexes (2) are obtained, containing three covalent Ni—C-σ-bonds of square planar nickel atoms. These bonds are strongly stabilized by the proximity of the ylid onium center. Excess ylid converts 2 into a binuclear complex 3, where the metal atoms are bridged by dimethylphosphonium-bismethylid units, with formation of [(CH3)4P]Cl as a byproduct. An isoelectronic dimethylphosphinate complex, 4, containing a similar eight-membered ring structure, has also been prepared.
    Notes: Durch die Reaktion von Dimethyltris(trimethylphosphin)nickel und Methylbis(trimethyl-phosphin)nickel-chlorid mit Trimethylmethylenphosphoran werden molekulare (1) bzw. ionische (2) Ylid-Komplexe erhalten, in denen das quadratisch-planar konfigurierte Nickel-atom jeweils drei kovalente Ni—C-σ-Bindungen ausbildet. Diese Bindungen werden durch das Onium-Zentrum der Ylide erheblich stabilisiert. 2 liefert mit überschüssigem Ylid unter Abspaltung von [(CH3)4P]Cl einen zweikernigen Komplex 3, dessen Metallatome durch Dimethylphosphonium-bis-methylid-Brücken verbunden sind. Hierzu existiert ein isoelektronischer Dimethylphosphinat-Komplex 4, der ebenfalls Achtringstruktur besitzt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070111
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  • 138
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    Reaktionen carbonyl-stabilisierter Sulfonium-ylide des 1,3-Dithiolans mit Acylierungsmitteln und aktivierten Acetylenen (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 123-127 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of carbonyl-stabilized Sulfonium-ylides of 1,3-Dithiolane with Acylating Reagents and Activated AcetylenesIn aqueous sodium hydroxide monophenacyl-1,3-dithiolanium bromides 3 form carbonylstabilized 1,3-dithiolanium-1-phenacylides 4. These yield with acylation reagents and activated acetylenes new resonance-stabilized sulfonium-ylides 6, 8, 10.
    Notes: Monophenacyl-1,3-dithiolanium-bromide 3 bilden in wäßriger Natronaluge carbonyl-stabilisierte 1,3-Dithiolanium-1-phenacylide 4. Diese reagieren mit Acylierungsmitteln und aktivierten Acetylenen zu neuen mesomeriestabilisierten Sulfonium-yliden 6, 8, 10.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070115
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  • 139
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    Über Aminosäuren und Peptide, IX. Über Pyruvoylaminosäuren (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 145-151 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On Amino Acids and Peptides, IX. On Pyruvoyl Amino AcidsAmino acid derivatives were tranformed to Pyruvoyl amino acid derivatives by use of pyruvoyl chlorid, p-nitrophenyl pyruvate, hydroxymaleic anhydride and the DCC-procedure. The application range of the different acylations is discussed. A convenient method for the preparation of pyruvoyl chloride is given.
    Notes: Aminosäurederivate werden mit Brenztraubensäurechlorid, Brenztraubensäure-p-nitrophenylester, Hydroxymaleinsäureanhydrid und mit Hilfe des DCC-Verfahrens zu Pyruvoylaminosäurederivaten umgesetzt. Die Anwendungsbreite der verschiedenen Acylierungen wird verglichen. Ein Weg zur praktischen Herstellung von Brenztraubensäurechlorid wird ausgearbeitet.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070118
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    Kristall- und Molekülstruktur von Hexakis(phenylthio)äthan (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 253-262 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Crystal and Molecular Structure of Hexakis(phenylthio)ethaneThe structure of hexakis(phenylthio)ethane has been determined by single crystal X-ray diffraction. The phase determination was carried out by means of the Symbolic Addition Method. The structure has been refined with 1780 observed reflections to an R-value of 10.9%. The pseudo bodycentered unit cell contains two molecules, which are situated at the center at 0, 0, 0 and 1/2, 1/2, 1/2, respectively. The bodycentering is almost perfect for the six sulfur atoms, but does not involve the central ethane bonding, which implies that the sulfur atoms, that are connected by the centering, are bonded to different carbon atoms. The six sulfur atoms are staggered around the ethane C—C bond. The S—C—S angles of 113° are larger than the ideal tetrahedrane angles by the same amount by which the S—C—C angles of 105° are smaller. The ethane C—C distances are 1.59 and 1.56 Å respectively.
    Notes: Die Struktur des Hexakis(phenylthio)äthans wurde mit Röntgenmethoden bestimmt. Die Phasenbestimmung wurde mit der symbolischen Additionsmethode durchgeführt. Die Struktur wurde unter Benutzung von 1780 beobachteten Reflexen bis auf einen R-Wert von 10.9% verfeinert. Die pseudoinnenzentrierte Elementarzelle enthält zwei Moleküle, die um die Symmetriezentren in 0, 0, 0 bzw. 1/2, 1/2, 1/2 gelagert sind. Die Innenzentrierung ist nahezu genau für die sechs Schwefelatome, aber gilt nicht für die zentrale Äthanbindung, was zur Folge hat, daß die durch Zentrierung verbundenen Schwefelatome an verschiedene Kohlenstoffatome gebunden sind. Die sechs Schwefelatome sind gestaffelt um die Äthan-C—C-Bindung angeordnet. Die S—C—S-Winkel sind mit 113° etwas größer, die S—C—C-Winkel mit 105° um denselben Betrag kleiner als der Tetraederwinkel. Die Äthan-C—C-Abstände betragen 1.59 bzw. 1.56 Å.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070131
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  • 141
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    Benzothiazol-N-oxide, II. Über eine neue Synthese substituierter 2-Benzothiazolone (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 305-316 
    Details
    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
    URL: http://dx.doi.org/10.1002/cber.19741070136
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  • 142
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    Aromatische Sulfenylchloride, IX. Herstellung, Oxidation und spektroskopische Untersuchung von 1-substituierten (5-Tetrazolyl)aryldisulfiden (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 299-304 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Aromatic Sulfenyl Chlorides, IX. Preparation, Oxidation, and Spectroscopic Investigation of 1-Substituted 5-Tetrazolyl Aryl Disulfides1-Substituted 5-tetrazolyl mesityl disulfides were synthesized which on oxidation with hydrogen peroxide gave disulfide S2, S2-dioxides (thiolsulfonates). The structure of these as well as that of the 1-substituted 5-tetrazolyl p-tolyl disulfide S2, S2-dioxides synthesized earlier was elucidated by means of their i. r. and n. m. r. spectra. The supposed structures have been established by synthesis.
    Notes: Es wurden 1-substituierte (5-Tetrazolyl)mesityldisulfide hergestellt, welche zu Disulfid-S2, S2-dioxiden (Thiosulfonate) oxidiert wurden. Deren Struktur und die der früher hergestellten 1-substituierten (5-Tetrazolyl)p-tolyldisulfid-S2, S2-dioxide wurde anhand ihrer IR- und NMR-Spektren wahrscheinlich gemacht. Die angenommenen Strukturen wurden durch Synthese bewiesen.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070135
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  • 143
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    Lithio-1,3,5-trithiane Erzeugung, Umsetzung mit Elektrophilen und Verwendung als nucleophile Acylierungsmittel (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 367-379 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Lithio-1,3,5-trithianes Generation in Solution, Reactions with Electrophiles, and Use in Nucleophilic Acylation1,3,5-Trithiane and 2-mono- as well as 2,4,6-trisubstituted trithianes are shown to be metallated by n-butyllithium in THF. Reaction of the lithio derivatives thus obtained with electrophiles leads to more highly substituted trithianes which in some cases can be isolated in a pure form. The n.m.r. spectra of the products at room temperature are described. Mercury(II)-assisted solvolysis of alkyltrithianes „liberates“ the most highly substituted carbon with formation of carbonyl compounds or their O-acetals. This completes a sequence of reactions which suggests use of lithiotrithianes as reagents for nucleophilic acylation. Advantages and disadvantages of this procedure compared to the dithiane method are discussed.
    Notes: 1,3,5-Trithian selbst sowie 2-mono- und 2,4,6- trisubstituierte Trithiane lassen sich mit n-Butyllithium in Tetrahydrofuran metallieren. Umsetzung der Lithiumderivate mit Elektrophilen führt zu höher substituierten Trithianen, die teilweise in reiner Form isoliert werden können. Die NMR-Spektren der erhaltenen Produkte bei Raumtemperatur werden beschrieben. Quecksilber(II)-assistierte Solvolyse von alkylierten Trithianen führt zu Carbonyl-verbindungen oder deren O-Acetalen unter „Herauslösung“ des höchstsubstituierten C-Atoms, was die Verwendung von Lithiotrithianen als nucleophile Acylierungsmittel ermöglicht. Vor- und Nachteile gegenüber der Dithian-Methode werden diskutiert.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070202
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    Über die Abhängigkeit der Bindungslängen in einigen N,O-Dibenzoylhydroxylaminen von der Verdrillung der Carboxyl- und Hydroxamsäuregruppen gegen die Benzolkerne Die Kristallstrukturen von N,O-Dibenzoyl-(C14H11NO3), N,O-Bis(2- chlorbenzoyl)-(C14H9Cl2NO3), N-Benzoyl-O-p-toluoyl- (C15H13NO3) und N-Benzoyl-O-o-toluoylhydroxylamin (C15H13NO3) (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 398-413 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Dependence of the Bond-length in some N,O-Dibenzoylhydroxylamines on the Torsion of the Carboxylic and Hydroxamic Groups against the Benzene Nuclei. The Crystal Structures of N,O-Dibenzoyl-(C14H11NO3), N,O-Bis(2-chlorobenzoyl)-(C14H9Cl2NO3), N-BenzoylO-p-toluoyl- (C15H13NO3), and N-Benzoyl-O-o-toluoylhydroxylamines (C15H13NO3)The crystal structures of four N,O- dibenzoylhydroxylamines - 1: N,O-dibenzoylhydroxylamine (C14H11NO3), 2: N,O- bis(2-chlorobenzoyl)hydroxylamine (C14H9Cl2NO3), 3: N-Benzoyl-O-p toluoylhydroxylamine (C15H13NO3), 4: N-benzoyl-O-o- toluoylhydroxylamine (C15H13NO3) - have been determined by X-ray techniques, using direct methods for phase determination. The torsion angles ϕ of the C—C- bonds between the phenyl groups and the hydroxamic acid groups or the carboxylic groups, respectively, have been calculated. The values of the intramolecular distances of these bonds, plotted versus cos2 ϕ, can be approximated by a straight line. Extrapolating to ϕ = 90°, the pure sp2-sp2-C—C-single-bond is found to be 1.513 Å.
    Notes: Die Kristallstrukturen von vier N,O- Dibenzoylhydroxylaminen - 1: N,O-Dibenzoylhydroxylamin (C14H11NO3), 2: N,O -Bis(2-chlorbenzoyl)hyroxylamin (C14H9Cl2NO3), 3: N-Benzoyl-O-p-toluoylhydroxylamin (C15H13NO3), 4: N- Benzoyl-O-o-toluoylhydroxylamin (C15H13NO3) - wurden röntgenographisch unter Anwendung direkter Methoden zur Lösung des Phasenproblems bestimmt. Die C—C- Bindungslängen zwischen den Phenylgruppen einerseits und den Hydroxamsäure- bzw. Carboxylatgruppen andererseits lassen sich als Funktion der Verdrillungswinkel ϕ dieser Bindung durch eine Gerade darstellen, wenn man die Bindungslängen gegen cos2 ϕ aufträgt. Der reine sp2-sp2-C—C- Einfachbindungsabstand (ϕ = 90°) ist danach 1.513 Å.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070205
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  • 145
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    Eine neue Synthese für Tetracyclo[3.3.0.02,8.04,6]octan-3-one durch intramolekulare [2π + 2 σ]-Thermocycloaddition (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 680-685 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A New Synthesis of Tetracyclo[3.3.0.02.8.04.6]octan-3-ones by Intramolecular Thermal [2π + 2σ]-CycloadditionThe synthesis of the tetracyclooctanone 19 by thermolysis of the tricyclic acetal 15 and subsequent removal of the acetal group is described. Thus, a third synthetic access to this system is now available. The reaction involves the cycloaddition of a thermally ring-opened cyclopropane to a double bond.
    Notes: Die Synthese des Tetracyclooctanons 19 durch Thermolyse des tricyclischen Acetals 15 und anschließende Entacetalisierung wird beschrieben. Damit bietet sich ein dritter synthetischer Zugang zu diesem System an. Die Reaktion beinhaltet die Cycloaddition eines thermisch ringgeöffneten Cyclopropans an eine Doppelbindung.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070240
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  • 146
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    Notiz zur Alkylierung des Dithizons (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 717-720 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070247
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  • 147
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    Notiz zur thermischen Valenzisomerisierung des Norpinens (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 731-734 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070251
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  • 148
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    Pteridine, LX. Synthese und Oxidationsverhalten von 7,8-Dihydroxanthopterinen (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 785-795 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Pteridines, LX. Synthesis and Autoxidation of 7, 8-DihydroxanthopterinsThe synthesis of 7,8-dihydroxanthopterin (18) and of various N- and C-methyl derivatives (19-27, 30) is described. Their pKa values and u.v. spectra have been determined and the behaviour during autoxidation has been investigated. The monoanions are subject to autoxidation which is catalysed strongly by ammonia and primary amines. A mechanism for the autoxidation is discussed in which the existence of various intermediates is based on the oxidative behaviour of differently blocked N- und C-methyl derivatives.
    Notes: Die Synthese des 7,8-Dihydroxanthopterins (18) und verschiedener N- und C-Methyl-Derivate (19-27, 30) wird beschrieben. Ihre pKa-Werte und UV-Spektren werden bestimmt und ihr Autoxidationsverhalten untersucht. Die Monoanionen unterliegen der Autoxidation, welche durch Ammoniak und primäre Amine stark katalysiert wird. Ein Mechanismus wird diskutiert und verschiedene Zwischenprodukte anhand von blockierten N- und C-Methyl-Derivaten wahrscheinlich gemacht.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070305
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  • 149
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    Die Kristall- und Molekülstruktur des 6,6-Bis(dimethylamino)fulvens (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 832-837 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Crystal and Molecular Structure of 6,6-Bis(dimethylamino)fulvene6,6-Bis(dimethylamino)fulvene crystallizes in the space group Pn21a, the lattice constants being ao = 13.344 Å, bo = 7.844 Å and co = 9.438 Å. The structure has been solved by superposition and by direct methods in the space group Pnma. The structure was refined by block-diagonal-least-squares to R = 0.037.
    Notes: Das 6,6-Bis(dimethylamino)fulven kristallisiert in der Raumgruppe Pn21a mit den Gitter-konstanten ao = 13.344 Å, bo = 7.844 Å und co = 9.438 Å. Die Struktur wurde durch Superposition und anschließende Resymmetrisierung der Patterson-Funktion und mit direkten Methoden in der zentrosymmetrischen Obergruppe Pnma gelöst.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070309
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  • 150
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    Brom-Lithium-Austausch an Vinyl- und Aryl-bromiden mit tert-Butyllithium Zur Ringerweiterung über Dibromcarbenaddukte (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 847-853 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Bromine/Lithium Exchange in Vinyl and Aryl Bromides with tert-Butyl Lithium. On the Ring Enlargement via Dibromocarbene AdductsTwofold molar excess of tert-butyl lithium replaces vinylic and arylic bromine by lithium. The tert-butyl bromide formed is dehydrohalogenated rapidly to isobutene by tert-butyl lithium even at very low temperatures. Transformation of 1-bromo-1-cyclooctene and - cyclononene via the lithium derivatives to vinyl thioethers 1d, e, and i in high yields opens up a simple alternative route from olefin dibromocarbene adducts to ring enlarged ketones. The bromobenzenes 2a and 3a reveal that the Br/Li-exchange described here is not accompanied by arine formation; it is feasible even in the presence of sensitive benzylic CH2-groups as present in 3.
    Notes: Vinylisch und an Aromaten gebundenes Brom läßt sich quantitativ mit zweifachem molarem Überschuß an tert-Butyllithium gegen Lithium austauschen. Das entstehende tert-Butylbromid wird selbst bei tiefen Temperaturen von tert-Butyllithium rasch zu Isobuten dehydrohalogeniert. Die Überführung von 1-Brom-1-cycloocten und -1-cycloneone in Vinylthioäther 1d, e und i über die Lithiumderivate ist in hoher Ausbeute möglich und eröffnet einen einfachen Weg von Dibromcarbenaddukten an Olefine zu ringerweiterten Ketonen. Am Beispiel der Brombenzole 2a und 3a wird gezeigt, daß der hier beschriebene Br/Li-Austausch nicht von Arin-Bildung begleitet und auch in Gegenwart der empfindlichen benzylischen CH2-Gruppe von 3 durchführbar ist.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070311
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  • 151
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    Über N-Vinylimidazolcarbonsäureester (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 892-897 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: N-VinylimidazolecarboxylatesN-Vinylation of imidazolecarboxylates with vinyl acetate leads to the formation of the N-vinylimidazoles 3a, 3b, 6, 8a, 8b und 9a. The structures are determined by mass and n.m.r. spectra. 3a, 6, 8a are polymerizable.
    Notes: Durch N-Vinylierung von Imidazolcarbonsäureestern mit Vinylacetat werden die N-Vinylimidazole 3a, 3b, 6, 8a, 8b und 9a, erhalten. Die Strukturen werden mit Hilfe von NMR-und Massen-Spektren gesichert. 3a, 6, 8a und 8bsing polymerisationsfähig.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070316
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  • 152
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    Heterocyclisierungen, XIII. Neue polycyclische Pyrimidine mit Brückenkop-Stickstoff (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 929-936 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Heterocyclizations, XIII. New Polycyclic Pyrimidines with Bridge-Head NitrogenThe base-catalized condensation of 2,3,3-trimethyl-3H-benz[f]indole (9) with dielectrophilic iso(thio)cyanates to polycyclic pyrimidines with bridge-head nitrogen (11, 15, 16) in most cases involves preliminary formation of 1: 2 adducts followed by elimination of diacylamides. Contrary to this the less nucleophilic 2,3,3-trimethyl-3H-pyrrolo [2,3-b]pyridine (20) affords the analogue pyrimidines by intermediacy of 1:1 adducts and elimination of water or ethanol solely.
    Notes: Die basenkatalysierte Kondensation von 2,3,3-Trimethyl-3H-benz[f] indol (9) mit dielektrophilen Iso(thio)cyanaten zu polycyclischen Pyrimidinen mit Brückenkopf-Stickstoff (11, 15, 16) verläft meist über die Bildung von 1:2-Addukten als Zwischenstufe und Eliminierung von Diacylamiden. Dagegen liefert das weniger nucleophile 2,3,3-Trimethyl-3 H-pyrrolo[2.3-b]-pyridin (20) analoge Systeme (22, 23) ausschließlich über 1: 1-Addukte und Eliminierung von Wasser bzw. Äthanol.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070321
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    Alkaloide aus Rhamnaceen, XVIII. Amphiin-F, -G und -H, weitere Peptidalkaloide aus Ziziphus amphibia A. Cheval (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 686-697 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Alkaloids from Rhamnaceae, XVIII. Amphibine-F, -G and -H, further Peptide Alkaloids from Ziziphus amphibia A. Cheval.From the complex mixture of crude alkaloids from Ziziphus amphibia A. Cheval., in addition to the already described Amphibines-A, -B, -C, -D and -E, three further peptide alkaloids Amphibine-F, -G and -H have been isolated and their structures elucidated (1-3). Amphibine-F and -G (1, 2) belong to the class of cyclic peptide alkaloides having a fourteen-membered ring system made up from trans-3-hydroxyproline, p-hydroxystyrylamine and an α-aminoacid. Amphibine-H (3) has a thirteen-membered ring system formed from 5-hydroxy-2-methoxystyrylamine and the aminoacids trans-3-hydroxyproline and phenylalanine.
    Notes: Aus dem komplexen Rohbasengemisch von Ziziphus amphibia A. Cheval. wurden neben den bereits beschriebenen Amphibinen-A, -B, -C, -D und -E drei weitere Peptidalkaloide Amphibin-F, -G und -H isoliert und in der Struktur geklärt (1-3). Die Amphibine-F und -G (1, 2) zählen zu den Cyclopeptidalkaloiden mit 14 gliedrigem Ringsystem aus trans-3-Hydroxyprolin, p-Hydroxystyrylamin und einer α-Aminosäure. Das Amphibin-H (3) weist ein 13 gliedriges Ringsystem auf, das aus den Aminosäuren trans-3-Hydroxyprolin und Phenylatanin sowie aus 5-Hydroxy-2-methoxystyrylamin gebildet wird5).
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070241
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    Über die Darstellung neuer Chlorformamidine (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 698-705 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Preparation of New ChloroformamidinesAction of phosphine/carbon tetrachloride or dichlorotriphenylphosphorane on N,N,N′-trisubstituted ureas leads to the formation of even such chloroformamidines which are not or only difficultly obtainable by the conventional methods. The spectroscopic and analytic data of the new compounds are given.
    Notes: Durch Einwirkung von Phosphin/Tetrachlorkohlenstoff oder von Dichlortriphenylphos-phoran auf N,N,N′-trisubstituierte Harnstoffe können auch solche Chlorformamidine dargestellt werden, die nach den bisherigen Methoden nicht oder nur schwer zugänglich sind. Die spektroskopischen und analytischen Daten der neuen Verbindungen sind angegeben.
    Additional Material: 5 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19741070242
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    Notiz über eine verbesserte Methode zur spezifischen Freisetzung oder Acylierung primärer Hydroxylgruppen ausgehend von pertrimethylsilylierten Polyolen (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 721-724 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070248
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  • 156
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    Notiz zur transanularen n/π-Wechselwirkung in 2,5-Dihydrofuran (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 725-726 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070249
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  • 157
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    Heterosubstituierte Fulvene, VIII. Indeno[2,1-c]-1,2-dithiole, eine Gruppe neuer Pseudoazulene (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 739-744 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Heterosubstituted Fulvenes, VIII. Indeno[2,1-c]-1,2-dithioles, a Group of New PseudoazulenesAcylation of 2-pyrrolidinoindene (4) with carboxylic acid chlorides and subsequent hydrolysis leads to the 1-acyl-2-indanones 6, which have been condensed with diacetyl disulfide in aequous perchloric acid/acetic acid to afford the 8H-indeno[2,1-c]-1,2-dithiolium-perchlorates 7. These are deprotonated with N-ethyldiisopropylamine to yield the indeno[2,1-c]-1,2-dithioles 10, a group of new pseudoazulenes.
    Notes: Acylierung von 2-Pyrrolidinoinden (4) mit Carbonsäurechloriden und nachfolgende Verseifung liefert die 1-Acyl-2-indanone 6, die mit Diacetyldisulfid in wäßriger Perchlorsäure, Eisessig zu den 8H-Indeno[2,1-c]-1,2-dithiolium-perchloraten 7 kondensieren. Letztere lassen sich durch N-Äthyldiisopropylamin zu den Indeno[2,1-c]-1,2-dithiolen 10, einer Gruppe neuer Pseudoazulene, deprotonieren.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070301
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  • 158
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    Stereochemie und reaktives Verhalten tetrahalogenierter 2,3-Diazabicyclo[3.2.0]hept-2-ene und Bicyclo[2.1.0]pentane (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 759-770 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stereochemistry and Reactivity of Tetrahalogenated 2,3-Diazabicyclo[3.2.0]hept-2-enes and Bicyclo [2.1.0] pentanesThe addition of diazoalkanes to tetrahalogenated cyclobutenes 1-3 leads to 6,6,7,7-tetrahalo-2,3-diazabicyclo[3.2.0]hept-2-enes 4-8, the structure and stereochemistry of which are determined by means of n. m. r. spectroscopy. Thermal decomposition of 4, 5, and 8 in boiling toluene affords the tetrahalobicyclo[2.1.0]pentanes 9, 10, and 12 in good yields. Under the same conditions 7 decomposes in a stereospecific manner to form 11 and small amounts of 13. Sodium methoxide converts 9-11 into the cyclobutenes 14 and 15. Under the influence of sulfuric acid 10 forms the cyclobutenedione 16 or a mixture of cyclopentenones 18, 19 depending on the reaction conditions.
    Notes: Addition von Diazoalkanen an die tetrahalogenierten Cyclobutene 1-3, führt zu 6,6,7,7-Tetrahalogeno-2,3-diazabicyclo[3.2.0]hept-2-enen 4-8, deren Konstitution und Stereochemie auf NMR-spektroskopischem Weg ermittelt wurde. Durch thermische Zersetzung der Bicyclen 4,5 und 8 in siedendem Toluol erhält man in guten Ausbeuten Tetrahalogenobicyclo-[2.1.0]pentane 9,10 und 12. Unter gleichen Bedingungen entstehen aus 7 in stereospezifischer Reaktion 11 sowie geringe Mengen des Cyclobutens 13. Mittels Natriummethylat werden die Bicyclen 9-11 zu den Cyclobutenen 14, 15 abgebaut; unter dem Einfluß von konz. Schwefelsäure entsteht aus 10 je nach Reaktionsbedingungen das Cyclobutendion 16 bzw. ein Gemisch der Cyclopentenone 18 und 19.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070303
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  • 159
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    Ein Eintopfverfahren zur Überführung von Aldehyden in Nitrile (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1221-1227 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Conversion of Aldehydes into Nitriles without Isolation of IntermediatesAldehydes are converted into nitriles without isolation of the intermediates by treating their oximes with carbodiimides in the presence of copper(II)ions and triethylamine. The entire process requires 3 hours at room temperature; it is unsuccessful if the oxime does not form or is consumed by competition reactions.
    Notes: Aldehyde können ohne Isolierung von Zwischenprodukten in Nitrile übergeführt werden, indem ihre Oxime in Gegenwart von Kupfer(II)-Ionen und Triäthylamin mit Hilfe von Carbodiimiden dehydratisiert werden. Der gesamte Prozeß erfordert bei Raumtemperatur durchweg 3 Stunden. Das Verfahren versagt, wenn die Oximbildung gestört ist oder das Oxim Konkurrenzreaktionen eingeht.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070418
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  • 160
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    Synthese und Reaktivität von Silicium-Übergangsmetallkomplexen, V. Die modifizierte Alkalisalz-Eliminierungsmethode  -  ein genereller Weg zu Komplexen mit Silicium-Übergangsmetall-Struktureinheiten (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 979-995 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Reactivity of Silicon Transition Metal Complexes, V. The Modified Alkali Salt Elimination Method  -  a General Procedure for the Synthesis of Silicon Transition Metal CompoundsThe heterogeneous reaction of the sodium carbonylmetallates Na[Fe(CO)2π-C5H5], Na[M(CO)3π-C5H5] (M=Mo, W), and Na[Mn(CO)5] with various halo- and organohalosilanes leads to the formation of the corresponding silyl complexes. The new compounds are characterized by spectroscopy and the chemical properties are described. The results of a decomposition study of the trimethylsilyl-VIB transition metal complexes are discussed in connection with former synthetic experiments. Exchange reactions of these species with heterosiloxanes can be used for a qualitative estimation of relative metal-metalloid bond reactivity.
    Notes: Die Umsetzung der komplexen Metallate Na[Fe(CO)2π-C5H5], Na[M(CO)3π-C5H5] (M=Mo, W) und Na[Mn(CO)5] mit verschiedenen Halogen- und Organohalogensilanen führt in heterogener Reaktion zu den Silylkomplexen dieser Metalle. Die neuen Verbindungen werden spektroskopisch charakterisiert und ihre chemischen Eigenschaften beschrieben. Die Ergebnisse einer Zerfallsstudie der Trimethylsilyl-VIB-Übergangsmetallkomplexe werden im Zusammenhang mit früheren Syntheseversuchen diskutiert. Der Verlauf von Austauschreaktionen der gleichen Verbindungen mit Heterosiloxanen (Ge, Sn) ermöglicht eine qualitative Abschätzung der Reaktivität der Metall- Metalloideinheit.
    Additional Material: 7 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19741070326
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  • 161
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    Untersuchungen an 4-Pyronen, 51 Aminoalkylierung von Chromonen (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1057-1065 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Investigations on 4-Pyrones, 51. Aminoalkylation of ChromonesThe aminoalkylation of 2-methylchromones (1b, e and 2b, c) leads to the formation of benzopyrano[3.2-c]pyridinium chlorides (9a-d and 11a-e).
    Notes: Die Aminoalkylierung von 2-Methylchromonen (1b, e sowie 2b, c) führt zu Benzopyrano-[3.2-c]pyridinium-chloriden (9a-d sowie 11a-e).
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070334
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  • 162
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    Berichtigung (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1069-1069 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070336
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  • 163
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    Massenspektrometrische Untersuchung von Amiden, VII Intramolekulare Wechselwirkungen bifunktioneller Gruppen bei der elektronenstoßinduzierten Fragmentierung von Piperididen und Piperideiden (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1081-1091 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Mass Spectrometric Investigation of Amides, VII. Intramolecular Interactions of Bifunctional Groups in the electron Impact Induced Fragmentation of Piperidides and PiperideidesThe activation energy ∊ for the electron impact induced splitting of the N-carbonyl bond in bifunctional amides is estimated. A clear correlation is shown of ∊ with the ring size of the transition state and the nucleofuge or nucleophilic properties of the nitrogen groups. Furtheron by means of [D]-labelled model compounds selective hydrogen migrations have been established.
    Notes: Die Aktivierungsenergie ∊ für die elektronenstoßinduzierte Spaltung der N-Carbonylbindung bifunktioneller Amide wird bestimmt. Es ergibt sich ein klarer Zusammenhang von ∊ mit der Ringgröße des Übergangszustandes und den nucleofugen bzw. nucleophilen Eigenschaften der Stickstoffgruppen. Ferner werden mit Hilfe [D]-markierter Modellverbindungen selektive Wasserstoffübertragungen nachgewiesen.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070403
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  • 164
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    Über die Natur des Benzonorbornen-2-yl-Kations, II. Solvolyse von Isopropyliden-substituierten Benzonorbornen-2-yl-Estern (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1126-1135 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Nature of Benzonorbornen-2-yl Cations, II. Solvolysis of Isopropylidene-substituted benzonorbornen-2yl EstersThe 2-epimeric at C-7 and C-3 substituted benzonorbornenols 4a, 6a, 7a and 8a are synthesized. The rate of solvolysis of the tosylates 4b and 6b is measured in acetic acid, that of the 3,5-dinitrobenzoates 7b and 8b in 90% dioxane. The solvolysis products are determined in 80% acetone puffered with 2,6-lutidine. The epimeric 7-isopropylidene derivatives 4b and 6b solvolyse by a different mechanism; the exo derivative 4b reacts exclusively with assistance of the benzene ring, the endo compound by participation of the homoallylic double bond. The epimeric 3-isopropylidene derivatives 7b and 8b solvolyse to a common intermediate allylic ion 10. The kexo/kendo ratio is reduced to 9 due to the presence of this neighbouring group, which is a measure of the steric factor in the secondary benzonorbornen-2-yl system.
    Notes: Die epimeren Benzonorborneole 4a und 6a sowie 7a und 8a werden synthetisiert. Die Solvolysegeschwindigkeit der Tosylate 4b und 6b wird in Eisessig, die der 3,5-Dinitrobenzoate 7b und 8b in 90 proz. Dioxan gemessen. Die Reaktionsprodukte werden in 80 proz., mit 2,6-Lutidin gepuffertem Aceton bestimmt. Die epimeren 7-Isopropyliden-Verbindungen 4b und 6b solvolysieren nach einem unterschiedlichen Mechanismus; die exo-Verbindung 4b reagiert ausschließlich mit Beteiligung des Aromaten, die endo-Verbindung 6b mit der der Isopropyliden-Doppelbindung. Die epimeren 3-Isopropyliden-Verbindungen 7b und 8b solvolysieren zu einem gemeinsamen Allyl-Ion 10 als produktbestimmende Zwischenstufe. Das Verhältnis kexo/kendo wird durch diese Nachbargruppe auf 9 herabgesetzt, welches ein Maß für den sterischen Anteil des sekundären Benzonorbornen-2-yl-Systems ist.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070407
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  • 165
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    Übergangsmetall-Carben-Komplexe, LXXII. Spaltung der Doppelbindung von 1-Vinyl-2-pyrrolidon und β-substituierten 1-Vinylpyrrolidonen bei der Umsetzung mit Pentacarbonyl(methoxyphenylcarben)chrom(0) (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1156-1161 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Transition Metal Carbene Complexes, LXXII. Cleavage of the Double Bond of 1-vinyl-2-pyrrolidone and β-Substituted 1-Vinylpyrrolidones by Reaction with Pentacarbonyl(methoxyphenylcarbene)chromium(0)Pentacarbonyl(methoxyphenylcarbene)chromium(0) reacts with 1-vinyl-2-pyrrolidone to form α-methoxystyrene by transfer of a methylene group to the carbene moiety. The origin of the transfered methylene group is proved by using methylsubstituted 1-vinylpyrrolidones. The reaction products are identified by their i.r., 1H n.m.r., and mass spectra. As reaction mechanism a cyclic transition state is proposed, which explains the breaking and following formation of a double bond analogously to the heterolytic fragmentation according to Grob.
    Notes: Bei der Umsetzung von Pentacarbonyl(methoxyphenylcarben)chrom(0) mit 1-Vinyl-2-pyrrolidon entsteht durch Übertragung einer Methylengruppe auf den Carben-Rest α-Meth-oxystyrol. Durch Einsetzen methylsubstituierter 1-Vinylpyrrolidone wird die Herkunft der übertragenen Methylengruppe bewiesen. Die Produkte werden anhand ihrer IR-, 1H-NMR- und Massenspektren identifiziert. Als Reaktionsmechanismus wird ein cyclischer Übergangszustand vorgeschlagen, der - in Analogie zur heterolytischen Fragmentierung nach Grob - die Spaltung und Neuknüpfung einer Doppelbindung erklärt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070411
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  • 166
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    Photochemische Reaktionen, XXIII. Über Photocyclisierungen von 9-Benzylidenxanthenen und 9-Benzylidenthioxanthenen (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1207-1212 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photochemical Reactions, XXIII. The Photocyclisation of 9-Benzylidenexanthenes and 9-BenzylidenethioxanthenesDehydrocyclisations of the 9-benzylidenexanthenes in u.v. or sunlight (6a-6d→7a-7d) were realized. 6 may be considered as derived from stilbene, and 7 as derived from phenanthrene. Therefore the photoprocess 6→7 is analogue to the photoprocess cis-stilbene → phenanthrene.
    Notes: Dehydrocyclisierungen der Benzylidenxanthene im UV-oder Sonnenlicht (6a-6b→7a-7d) wurden durchgeführt. Da 6 als substituierte cis-Stilbene und 7 als substituierte Phenanthrene aufgefaßt werden können, liegen Analogiereaktionen zu dem Photoprozeß cis-Stilben → Phenanthren vor.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070416
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  • 167
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    Darstellung und dynamisches Verhalten von Mono- cyclopentadienylarsinen (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1228-1234 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation and Dynamic Behaviour of Mono-cyclopentadienylarsinesMono-cyclopentadienylarsines (3a-e) are synthesized by the reaction of cyclopentadienyl-trimethylsilane (1) or cyclopentadienyllithium (5) with the halogenoarsines 2a-e. They are very sensitive against air and moisture and thermally unstable. The cp-ligands are σ-bonded; the molecules have a fluxional structure. The rapidity of the degenerate metallotropic rearrangements is influenced by the other ligands on the arsenic atom.
    Notes: Mono-cyclopentadienylarsine (3a-e) werden durch Umsetzung von Cyclopentadienyl-trimethylsilan (1) oder Cyclopentadienyllithium (5) mit den Halogenarsinen 2a-e dargestellt. Sie sind äußerst luft- und feuchtigkeitsempfindlich und thermisch instabil. Es liegen σ-gebundene Cp-Liganden und Moleküle mit fluktuierender Struktur vor. Die Geschwindigkeit der entarteten metallotropen Umlagerungen wird durch die anderen Liganden am Arsenatom beeinflußt.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070419
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    Enhydrazine, 9. 1-Alkyl-3-hydroxypyrazole aus Hydrazonen oder Hydrazinen (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1318-1328 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Enehydrazines, 9. 1-Alkyl-3-hydroxypyrazoles from Hydrazones or HydrazinesReaction of dimethyl acetylendicarboxylate with hydrazinen oder Alkyl hydrazonen gives the methyl 1-alkyl-3-hydroxy-5-pyrazolecarboxylats 9 and 13a-e, subsequent saponification and decarboxylation gives the 1-alkyl-3-hydroxypyrazoles 11 and 15a-e. The cyclization of 13f to lactone 19a is a structure proff. Starting from benzaldehyde hydrazones, 2-pyrazoline-4,5-dicarboxylic esters are the main products.
    Notes: Durch Umsetzung von Acetylendicarbonsäure- dimethylester mit Hydrazinen oder Alkyl-hydrazonen erhält man die 1-Alkyl-3-hydroxy-5-pyrazolcarbonsäure-methylester 9 und 13a-e, durch Verseifung und Decarboxylierung hieraus die 1-Alkyl-3-hydroxypyrazole 11 und 15a-e. Die Cyclisierung von 13f zum Lacton 19a ist strukturbeweisend. Bei Verwendung von Benzaldehyd-hydrazonen entstehen hauptsächlich 2-Pyrazolin-4,5- dicarbonsäureester.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070428
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    Elektrophile Addition von Dischwefeldichlorid an Alkine, 3. Umsetzung asymmetrisch substituierter Alkine mit Dischwefeldichlorid (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1334-1343 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Electrophilic Addition of Disulfur Dichloride to Alkynes, 3. Reaction of Asymmetric of Asymmetric Substituted Alkynes with Disulfur DichlorideDisulfur dichloride adds to the triple bond of asymmetric substituted alkynes to afford vinyl sulfides, which are constitution isomers. Substituents R with a negative I-effect yield „Markownikof“ products whereas a positive I-effect leads to the formation of „anti-Markownikoff“ products. The addition is always trans. The obtained sulfides are oxidized with H2O2 in glacial acetic acid to yield the corresponding sulfones.
    Notes: Die bei der elektrophilen Addition von Dischwefeldichlorid an asymmetrische Alkine gebildeten Vinylsulfide sind Konstitutions -Isomere. Substituenten R mit negativem Induktionseffekt führen zu „Markownikoff“-Produkten, während ein positiver I-Effekt „anti-Markownikoff“-Orientierungen liefert. In allen Fällen erfolgt eine trans-Addition. Die erhaltenen Sulfide werden nach der Oxidation mit Wasserstoffperoxid/Eisessig als Sulfone isoliert.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070430
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    Oxidative Additionsreaktionen von Nitroalkanen an Tetrakis(triphenylphosphin)platin(0) (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1371-1379 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Oxidative Addition Reactions of Nitroalkanes to Tetrakis(triphenylphoshine)platinum(0)The oxidative addition of nitromethane to Pt(PPh3)4 in polar protic solution provides a convenient and safe method for the preparation of trans-(Ph3P) 2Pt(CNO)2 Pt(CNO2)(3). From Pt(PPh3)4 and nitromethane or 2-nitropropane cis-(Ph3P) 2Pt(NO2)2 (2) is obtained. The reactions of Pd(PPh3)4 or Rh(PPh3)2CO)Cl with CH3NO2 or some of its derivatives afford isocyanato compounds. Formaidoxime hydrochloride reacts with Pt(PPh3)4 to give trans-(Ph3P)2Pt-(CN)Cl (4).
    Notes: Die oxidative Addition von Nitromethan an Pt(PPH3)4 in polarem, protischem Medium liefert gefahrlos und in guter Ausbeute trans-(Ph 3P)2Pt(CNO)2 (3). Aus Pt(PPh3)4 und Nitromethan bzw. 2-Nitropropan wird cis-(Ph3P)2Pt(NO2)2 (2) erhalten. Die Umsetzungen von Pd(PPh 3)4 oder Rh(PPh3)2(CO)Cl mit Nitromethan oder Methylnitrolsäure führen zu Isocyanatoverbindungen. Formaldoxim-hydrochlorid reagiert mit Pt(PPh 3)4 zu trans-(Ph3P)2Pt(CN)Cl (4).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070434
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  • 171
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    Botrydial, ein Sesquiterpen-Antibiotikum aus der Nährlösung des Pilzes Botrytis cinerea (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1720-1730 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Botrydial, a Sesquiterpene Antibiotic from the Culture Solution of the Fungus Botrytis cinereaThe antibiotic botrydial (3) and its dihydro derivative (1) were isolated from the culture solution of the fungus Botrytis cinerea. Their structural formulas were elucidated by means of a series of chemical transformations together with the application of spectroscopic methods, especially a detailed analysis of the n.m.r. spectra. The basic skeleton of botrydial is a bicyclic, non-isoprenoid sesquiterpene system.
    Notes: Aus der Nährlösung des Pilzes Botrytis cinerea wurden das antibiotisch wirksame Botrydial (3) und sein Dihydroderivat (1) isoliert. Durch eine Folge chemischer Umwandlungen, verbunden mit der Anwendung spektroskopischer Methoden, insbesondere einer detaillierten Analyse der NMR-Spektren, wurden ihre Konstitutionsformeln abgeleitet. Botrydial liegt ein bicyclisch nicht-isoprenoides Sesquiterpenskelett zugrunde.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19741070530
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  • 172
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    Natürlich vorkommende Terpen-Derivate, XXXIV. Notiz über die Synthese des Furanoeremophilans (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1767-1768 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070535
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  • 173
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    Natürlich vorkommende Terpen-Derivate, XXXVI. Synthese von 8-Hydroxybrickellol und Dehydronerol-isovalerat (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1773-1776 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Naturally Occuring Terpene Derivatives, XXXVI. Synthesis of 8-Hydroxybrickellol and Dehydronerol isovalerateThe sesquiterpene 7 named 8-hydroxybrickellol as well as the isovalerate of dehydronerol (14) have been synthesized.
    Notes: Das 8-Hydroxybrickellol benannte Sesquiterpen 7 sowie der Isovaleriansäureester des Dehydronerols (14) werden synthetisch dargestellt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070602
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  • 174
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    Die Reaktionen von Phosphor-yliden mit überschüssigem Alkohol und mit Alkanthiol (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1420-1427 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Reactions of Phosphorus Ylids with Excess Alkohol and AlkanethiolThe alkoxytetraalkylphosphoranes of the formula R4POR′, obtained from equimolar amounts of ylid and alkohol, which contain pentacoordinate phosphorus atoms, are converted into ionic products (1 - 7) by addition of excess alkohol. In these compounds phosphonium cations R4P⊕ are accompanied by hydrogen-bonded hydrogenalkoholate anions of the types [R′O…H…OR′]⊖, [H2(OR′)3]⊖, and [H3(OR′)4]⊖. This structure is proposed on the basis of n.m.r., i.r., and Raman-spectroscopic data. With ylids and alkanethiols only salt-like products R4P⊕RS⊖ are formed.
    Notes: Die aus äquimolaren Mengen von Yliden und Alkoholen zugänglichen, kovalent gebauten Alkoxytetraalkylphosphorane R4POR′ mit pentakoordinierten Phosphoratomen werden durch Addition von überschüssigem Alkohol in die Produkte 1 - 7 verwandelt, in welchen Phosphonium-Kationen R4P⊕ den wasserstoffbrückenverknüpften Hydrogenalkoholat-Anionen vom Typ [R′O…H…OR′]⊖, [H2(OR′)3]⊖ und [H3(OR′)4]⊖ gegenüberstehen. Der Strukturvorschlag stützt sich auf NMR-, IR- und Raman-spektroskopische Untersuchungen. Aus Yliden und Alkanthiolen entstehen nur die salzartigen Phosphonium-alkanthiolate R4 P⊕RS⊖.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070503
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  • 175
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    Umlagerungen 3-substituierter Norbornandiazonium-Ionen (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1472-1482 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Rearrangements of 3-Substituted Norbornanediazonium Ions3-Oxonorbornane-2-endo-diazonium ions (1), generated by acid-catalyzed decomposition of 3-diazonorcamphor (5) in alcoholic solutions, produce derivatives of endo-bicyclo[2.2.1]heptane 3 and bicyclo [3.1.1]heptane derivatives 4, varying with the nucleophilicity of the solvent. This suggests the 7-bridged ion 2 as intermediate, which plays also an important part in the deamination of 3,3-dimethoxynorcamphor tosylhydrazone (16) in alkaline solutions as shown by the formation of 3 and 4. In the alkaline deamination of 3,3- dimethoxy-5-norbornen-2-on tosylhydrazone (32) in methanol the homoallylic ion 34 is dominating.
    Notes: 3-Oxonorbornan-2-endo-diazonium-Ionen (1), erzeugt durch sauer katalysierte Zersetzung von 3-Diazonorcampher (5) in alkoholischen Lösungen, ergaben endo-Bicyclo[2.2.1]heptan-3 und Bicyclo[3.1.1]heptan-Derivate 4, deren Menge von der Nucleophilie des eingesetzten Lösungsmittels abhängig ist. Dies läßt das 7-verbrückte Ion 2 als Zwischenstufe vermuten, welches auch bei der Desaminierung des 3,3-Dimethoxynorcampher-tosylhydrazons (16) in alkalischen Lösungen eine entscheidende Rolle spielt, wie die Bildung der Produkte 3 und 4 beweist. Bei der alkalischen Desaminierung des 3,3-Dimethoxy-5-norbornen-2-on-tosylhydrazons (32) in Methanol ist jedoch die Homoallylumlagerung zum Kation 34 produkt-bestimmend.
    Additional Material: 4 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19741070507
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  • 176
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    Derivate des Guanidins mit N—S- und N—P-Bindungen (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1536-1544 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Derivatives of Guanidines Containing Phosphorus and SulfurN-Chloroguanidines 1 react with tervalent phosphorous compounds or with sulfides to yield N-guanylphosphine imidium (3) or sulfimidium salts (9). Dehydrohalogenation gives the respective N-guanyl phosphine imides and sulfimides. The structure and reactions of these compounds are discussed.
    Notes: Die Umsetzung von N-Chlorguanidinen 1 mit tervalenten Phosphorverbindungen sowie Sulfiden führt zu N-Guanylphosphinimidium- (3) bzw. -sulfimidium-Salzen (9). Durch Dehydrohalogenierung werden die entsprechenden Phosphinimide und Sulfimide erhalten. Die Eigenschaften dieser Verbindungen - insbesondere die Struktur-und Bindungsverhältnisse-sowie ihre Reaktionen werden untersucht.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070514
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  • 177
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    Konformationsanalyse, III. exo-Anomerer Effekt und Circulardichroismus von Glycopyranosylaziden (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1568-1578 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Conformational Analysis, III. exo-Anomeric Effect and Circular Dichroism of Glycopyranosyl AzidesTetra-O-acetyl-aldopentopyranoses and penta-O-acetyl-aldohexopyranoses react readily with trimethylsilyl azide in the presence of BF3 or SnCl4 to afford the corresponding glycosyl azides 1a - 11 (table 1). Only the anomeric glycosyl azide having the azido group „trans“ to the 2-acetoxy group is obtained in each case. The polarization of the Cl—Nx and Nx—Nz bonds in glycosyl azides is such that in both cases the dipole is directed toward Nx. It can be deduced that glycosyl azides, like methyl glycopyranosides, should exhibit an exo-anomeric effect which strongly favors the conformers 9 and 12. The application of the azide-octant rule predicts a negative Cotton effect for the α-D-glycosyl azide 12 and a positive effect for the β-D-glycosyl azide 9. Circular dichroism measurements are in good agreement with these predictions, indicating the operation of an exo-anomeric effect in the glycosyl azides.
    Notes: Tetra-O-acetyl-pentopyranosen und Penta-O-acetyl-hexopyranosen setzen sich mit Trimethylsilylazid bei Gegenwart von BF3 oder SnCl4 leicht zu den entsprechenden Glycosylaziden 1a bis 11 um (Tab. 1). Es entsteht stets nur das anomere Glycosylazid, in dem die Azidogruppe und 2-OAc „trans“ zueinander angeordnet sind. In Glycosylaziden sind die Bindungen Cl—Nx und Nx—Nz in der Weise polarisiert, daß der Dipol in beiden Fällen zum Nx weist. Hieraus wird abgeleitet, daß bei Glycosylaziden wie bei Methylglycosiden ein exo-anomerer Effekt wirksam sein sollte, der die Konformeren 9 und 12 stark bevorzugt. Die Anwendung der Azid-Oktantenregel sagt für das α-D-Glycosylazid 12 einen negativen, für das β-D-Glycosylazid 9 einen positiven Cotton-Effekt voraus. Messungen des Circular-dichroismus stimmen mit diesen Voraussagen gut überein, was für einen exo-anomeren Effekt bei Glycosylaziden spricht.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070517
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  • 178
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    Thermisch induzierte Reaktionen von Imidazolderivaten, IV. Die Kinetik der thermischen Umlagerung von 2,4,4-Thriaryl-5-mathylthio-4H-imidazolen (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1645-1648 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thermally Induced Reactions of Imidazole Derivatives, IV. Kinetics of the Thermal Rearrangement of 2,4,4-Triaryl-5-methylthio-4H-imidazolesThe thermal rearrangements of the title compounds 1a - d into the 2,4,5-triarylimidazoles 2 in different solvents and at different temperatures are first order reactions. No linear relation exists between the effect of the p-substituents of the migrating aryl groups on the reaction rates and their Hammett-Brown σ+ values. The solvent has practically no effect on the rearrangement rate of 1c. The activation parameters of the rearrangement 1c → 2c are given.
    Notes: Die thermische Umlagerung der Titelsubstanzen 1a - d in die 2,4,5-Triarylimidazole 2 in verschiedenen Lösungsmitteln und bei verschiedenen Temperaturen folgt einem Geschwindigkeitsgesetz 1. Ordnung. Der Einfluß des p-Substituenten der wandernden Arylgruppe ändert sich nicht linear mit den Hammett-Brownschen σ+-Werten. Das Lösungsmittel hat praktisch keinen Einfluß auf die Umlagerungsgeschwindigkeit von 1c. Die Aktivierungsparameter der Umlagerung 1c → 2c werden angegeben.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070522
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  • 179
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    Vinyl-Kationen, 15. Darstellung und Solvolyse der stereoisomeren 1-Brommethylen-2-methylcyclopropane (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1676-1683 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Vinyl Cations, 15. Preparation and Solvolysis of the Stereoisomeric 1-Bromomethylene-2-methylcyclopropanesThe stereoisomeric 1-bromomethylene-2-methylcyclopropanes (6Z and 6E) are synthesized and their solvolysis rates and products in ethanol/Water mixtures are determined. 6Z and 6E solvolyse at approximately the same rates. Both isomers yield only the rearranged products 12, 14, 16 and 18, which are formed from both isomers in the same ratio. The products as well as the kinetic data are explained by assuming the formation of the stabilized cyclopropylidenemethyl cation 7.
    Notes: Die stereoisomeren 1-Brommethylen-2-methylcyclopropane (6Z und 6E) wurden dargestellt und die Solvolysegeschwindigkeiten sowie die Produkte in Äthanol/Wasser-Gemischen bestimmt. 6Z und 6E solvolysieren dabei etwa mit gleicher Geschwindigkeit. Aus beiden Isomeren entstehen ausschließlich die umgelagerten Produkte 12, 14, 16 und 18 im gleichen Mengenverhältnis. Produktanalyse und Kinetik werden mit der Bildung des stabilisierten Cyclopropylidenmethylkations 7 erklärt.
    Additional Material: 2 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19741070526
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  • 180
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    Dispiro[2.0.2.4] deca-7,9-dien und Vergleichsverbindungen: Darstellung, UV-, NMR- und Photoelektronen-spektroskopische Untersuchungen (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1684-1701 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Dispiro[2.0.2.4]deca-7,9-diene and Related Model Compounds: Synthesis, U.V, N.M.R, and Photoelectron-Spectroscopic InvestigationsDispiro[2.0.2.4]deca-7,9-diene (4) and spiro[2.5]octa-4,6-diene (5 can be obtained from the corresponding monoolefins 6 and 10, respectively, by bromine addition and subsequent dehydrobromination. The u. v. spectra of 5 and 4 with λmax = 269 nm (log ε = 3.4) and 284 nm (3.7), respectively, show bathochromic shifts of their longest wavelength bands as compared to 1,3-cyclohexadiene. An analysis of the 1H n. m. r. chemical shifts and H, H-coupling constants for the olefinic protons in 4 indicates that there is no cyclic electron delocalization in this ring system. The six-membered ring in 4 is only slightly flatter than the one in 1,3- cyclohexadiene. The photoelectron spectroscopic data of 4, 5, spiro[2.5]octane (13), spiro[2.5]oct-4-ene (15), dispiro[2.0.2.4]decane (14), and dispiro[2.0.2.4]dec-7-ene (16) demonstrate the effect of the interaction between π-orbitals and cyclopropyl Walsh-orbitals; an assignment for the first bands in the p. e. spectra of these compounds is proposed.
    Notes: Dispiro[2.0.2.4] deca-7,9-dien (4) und Spiro[2.5]octa-4,6-dien (5) lassen sich aus den entsprechenden Monoolefinen 6 bzw. 10 durch Bromierung und anschließende Dehydrobromierung gewinnen. Die UV-Absorptionen von 5 und 4 mit λmax = 269 nm (log ε = 3.4) bzw. 284 nm (3.7) sind bathochrom verschoben gegenüber denjenigen des 1,3-Cyclohexadiens. Aus einer Analyse der Chemischen Verschiebungen und H,H-Kopplungskonstanten der olefinischen Protonen im 1H-NMR-Spektrum von 4 ist zu schließen, daß 4 kein cyclisch delokalisiertes Elektronensystem enthält. Der Sechsring in 4 ist nur wenig stärker eingeebnet als derjenige im 1,3-Cyclohexadien. Anhand der Photoelektronen-Spektren von 4, 5 sowie Spiro[2.5]octan (13), Spiro[2.5]oct-4-en (15), Dispiro[2.0.2.4]decan (14) und Dispiro[2.0.2.4]dec-7-en (16) wird der Effekt der Wechselwirkung zwischen π-Orbitalen und Cyclopropyl-Walsh-Orbitalen aufgezeigt; für die jeweils ersten Banden in den PE-Spektren dieser Verbindungen wird eine Zuordnung vorgeschlagen.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070527
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    Asymmetrische Hydrierungen mit 1,4-Bis(dimethylamino)- (2S,3S)-und -(2R,3R)-butan-2,3 -diol(DBD)/Lithiumaluminiumhydrid (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1748-1763 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Asymmetric Hydrogenation with 1,4-Bis(dimethylamino)-(2S,3S)- and -(2R,3R)-butane-2,3-dio(DBD)/Lithium Aluminium HydrideThe diaminodiol 6 (DBD) mentioned inthe in the title is readily available in two steps from commercial diethyl tartrate. It reacts with lithium aluminium hydride (LAH) or deuteride to give chirally modified 1:1-complexes which reduce aldehydes, ketones, and ozonides to optically active carbinols in optical yields of up to 75%. Since both enantiomers of DBD are to accessible, both dextro- and levo-rotatory products may be prepared at will. DBD is easily separated from products and recovered without loss of activity. The (-)- DBD-LAH-complex reduces both dialkyl and aryl alkyl ketones to give samples enantiomerically enriched with carbinols of (S)- configuration, while the (+)-DBD-complex acts the other way around. This result is independent of the mode of preparation of the complex, of the ratio of reducing reagent over substrate, of addition of alcohols or water, of reaction temperature, or solvent. The effects of some of these influences upon the optical yields are large. Optimum conditions are given; the efficiency of the DBD-LAH-complex is compared with similar chirally modified LAH derivatives already known. A mechanism explaining the stereochemical results is proposed.
    Notes: Das aus Weinsäureester in zwei Stufen leicht zugängliche, im Titel genannte Diaminodiol 6 (DBD) setzt sich mit Lithiumaluminiumhydrid (LAH) und -deuterid zu chiral modifizierten 1: 1-Komplexen um. Diese reduzieren Aldehyde, Ketone und Ozonide zu opt. aktiven Carbinolen in optischen Ausbeuten bis zu 75%. Da beide Enantiomeren von DBD zugänglich sind, lassen sich gezielt (+)- oder (-)-drehende Produkte darstellen. DBD ist von den Produkten bequem abtrennbar und ohne opt. Verluste zurückgewinnbar. Mit (-)-DBD-LAH- Komplex entstehen Dialkyl- und Alkyl-aryl- carbinole mit (S)-, aus dem enantiomeren Komplex mit (R)-Konfiguration des Überschußenantiomeren. Dies ist völlig unabhängig von Darstellungsmodus des Komplexes, molarem Verhältnis von Reduktionsmittel und Substrat, Zusätzen von Alkoholen oder Wasser, Reaktionstemperatur oder -lösungsmittel. Die Einflüsse dieser Faktoren auf die opt. Ausbeuten, für die optimale Bedingungen angegeben werden, sind indessen zum Teil groß. Vergleiche mit bekannten Komplexen aus LAH und anderen chiralen Liganden werden gezogen. Es wird ein Vorschlag zur Erklärung der stereochemischen Befunde gemacht.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19741070533
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    Natürlich vorkommende Terpen-Derivate, XXXVII. Synthese des Sesquiterpens aus Elvira biflora DC (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1777-1779 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Naturally Occurring Terpene Derivatives, XXXVII. Synthesis of the Sesquiterpene from Elvira biflora DCThe aromatic sesquiterpene 11 isolated from Elvira biflora DC has been synthesized starting with the p-cresol 2-butenyl ether (1).
    Notes: Das aus Elvira biflora DC isolierte aromatische Sesquiterpen 11 wird ausgehend vom p-Cresol-2-butenyläther (1) synthetisiert.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070603
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    Reaktionsverhalten von Nitril-yliden verschiedener Provenienz (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1823-1834 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactivity of Nitrile Ylides of Different OriginThermolysis and photolysis of 2,3-dihydro- 1,4,2λ5-oxazaphospholes 2, photolysis of 1- azetines 3 as well as 1,3-elimination of hydrogen chloride from imidoyl chlorides 4 proceeds via the nitrile ylide intermediate 1. This is deduced from the same product ratio of the isomeric cycloadducts 5:6 on trapping with acrylic acid esters.
    Notes: Die Thermolyse und Photolyse von 2,3-Dihydro-1,4,2λ5-oxazaphospholen 2, die Photolyse von 1-azetine 3 wie auch die 1,3-Eliminierung von Chlorwasserstoff aus Imidoylchloriden 4 verläuft über die Nitril-ylid-Zwischenstufe 1. Dies wird aus dem jeweils gleichen Produkt-verhältnis der isomeren Cycloaddukte 5:6 bei der Abfangreaktion mit Acrylsäureestern abgeleitet.
    Additional Material: 9 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19741070608
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    1,8-Di-tert-butyl-[9-13C]-9-fluorenyl, Bis (2-tert-butylphenyl) [α-13C]methyl und ihre Dimeren (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1903-1914 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 1,8-Di-tert-butyl-[9-13C]-9-fluorenyl, Bis(2-tert-butylphenyl)[α-13C]methyl and their DimersThe preparation of the title compounds is reported. The 1H n. m. r. spectra of the dimers of 1 and [9-13C]-1, respectively, yield the cyclohexadiene structure 12 for the dimer. The 1H n. m. r. spectrum of [α-13C]-2 dimer confirms structure 1411). The e. s. r. results of 1 and 2 are discussed.
    Notes: Die Darstellung der Titelverbindungen wird beschrieben. Die 1H-NMR-Spektren der Dimeren von 1 bzw. [9-13C]- 1 ergeben die Cyclohexadien-Struktur 12 für das Dimere. das 1H-NMR-Spektrum des [α-13C]- 2-Dimeren bestätigt die Struktur 14 11). Die ESR-Ergebnisse (a(H) und a(13C)) von 1 und 2 werden diskutiert.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19741070614
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    Photochemie kleiner Ringe, 30. Photochemie β, γ-ungesättigter Aldehyde. - Mechanismus der Photofragmentierung phenylsubstituierter Cyclopentencarbaldehyde (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1835-1855 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photochemistry of Small Rings, 30. Photochemistry of β,γ-Unsaturated Aldehydes.  -  Mechanism of the Photofragmentation of Phenyl-substituted CyclopentenecarbaldehydesA new synthesis of β,γ-unsaturated cyclopentenecarbaldehydes 1 by thermolysis of bicyclo-[3.1.0]hexenols 13 is described. Photolysis of the aldehydes 1 in benzene solution affords the cis-configurated cyclopentenes 2 in good yields. Cyclopentaphenanthrenes 16 are isolated as byproducts. 2 undergoes an electrocyclic reaction to form 17, which is then dehydrogenated to 16. The quantum yields of the photofragmentation and -cyclization are Φ2 = 0.23 and Φ16 = 0.07, respectively. From the emission spectra of 1a the energy of the singlet and triplet state is calculated to ES1 = 84.1 and ET1 = 62.2 kcal/mole. The kinetics of photoreactions 1 → 2 → 16 are studied using ED- and EDQ-diagrams. Sensitization studies demonstrate that the photoreaction 1 → 2 can also occur via a triplet state, but with reduced effectivity. Since quenching with piperylene is ineffective the reaction 1 → 2 very probably involves predominantly an n-π-singlet state. The mechanism proposed for the stereospecific, intramolecular reaction 1 → 2 involves the formation of a formyl allyl radical as a main intermediate.
    Notes: Eine neue Synthese von β,γ-ungesättigten Cyclopentencarbaldehyden 1 durch Thermolyse von Bicyclo [3.1.0]hexenolen 13 wird beschrieben. Die Photolyse der Aldehyde 1 in Benzol ergibt in guten ausbeuten die cis-konfigurierten Cyclopentene 2 und als Nebenprodukte die Cyclopentaphenanthrene 16.2 geht durch elektrocyclischen Ringschluß in 17 über, das unter Dehydrierung in 16 umgewandelt wird. Die Quantenausbeuten der photofragmentierung bzw. -cyclisierung betragen Φ2 = 0.23 bzw. Φ16 = 0.07. aus den Emissionsspektren von 1a wird die Energie von singulett- und Triplett-Zustand zu ES1 = 84.1 bzw. ET1 = 62.2 kcal/mol errechnet. Die Kinetik der Photoreaktionen 1 → 2 → 16 wird mit Hilfe von Ed- und EDQ-Diagrammen näher studiert. Wie Sensibilisierungsstudien zeigen, kann die Photoreaktion 1 → 2, wenn auch mit geringerer Effektivität, über einen Triplett-Zustand verlaufen. Sie läßt sich mit Piperylen nicht löschen, weshalb die Reaktion 1 → 2 weitgehend über einen angeregten n-π-S1-Zustand formuliert wird. Für den Mechanismus der stereospezifischen, intramolekularen (D-Markierung) Reaktion 1 → 2 wird ein Formyl-Allyl-Radikalpaar als Wesentliche Zwischenstufe vorgeschlagen.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19741070609
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    Photoelektronenspektren und Moleküleigenschaften, XXXIV. Cyanamid (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1882-1890 
    Details
    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, XXXIV. CyanamideThe PE spectrum of cyanamide is easily assigned by comparison with that of the isoelectronic acetonitrile. The orbital sequence obtained is supported by vibrational fine structures, by the PE spectrum of dimethylcyanamide, and by CNDO calculations. Furthermore, the calculated charge densities render possible an appreciation of properties of cyanamide and its alkyl derivatives.
    Notes: Das PE-Spektrum von Cyanamid läßt sich durch Vergleich mit dem des isoelektronischen Acetonitrils zwanglos zuordnen. Die so abgeleitete Orbitalreihenfolge wird durch Schwingungsfeinstrukturen, das PE-Spektrum von Dimethylcyanamid sowie durch CNDO-Rechnungen gestützt. Die berechneten Ladungsdichten erlauben darüber hinaus. Eigenschaften von Cyanamid und seinen Alkylderivaten zu verstehen.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19741070612
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  • 187
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    Kondensierte Ringsysteme VI. Synthese des [4.2.2]Propella-7,9-diens, eines 1,4-überbrückten Dewar-Benzols (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1915-1924 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Condensed Ring Systems, VI. Synthesis of [4.2.2]Propella-7,9-diene, a Dewar Benzene Bridged in 1,4-PositionThe reaction of 8,11-dithia [4.3.3] propellane (1, n = 4) with N-chlorosuccinimide and monoperphthalic acid yields a mixture of four isomeric dichlorinated disulfones (2, n = 4). The major isomer 7 is formed in 40% yield. Upon treatment of 2 (n = 4) with potassium tert-butoxide at low temperatures [4.2.2] propella-7,9-diene2) (3, n = 4) is obtained. The constitution of 3 (n = 4) is deduced by 1H and 13C n. m. r as well as mass spectrometry.
    Notes: Die Umsetzung des 8,11-Dithia [4.3.3] propellans (1, n = 4) mit N-Chlorsuccinimid und Monoperphthalsäure führt zu einem Gemisch von vier isomeren dichlorierten Disulfonen (2, n = 4), von denen das Hauptprodukt 7 in 40proz. Ausbeute entsteht. 2 (n = 4) läßt sich mit Kalium-tert-butylat bei tiefen Temperaturen in das [4.2.2]Propella-7,9-dien2)(3, n = 4) überführen, dessen Konstitution durch die 1H-, 13C-NMR- und Massenspektren bewiesen wird.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19741070615
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  • 188
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    Photoisomerisierung in Bicyclo[3.2.2]nona-6,8-dien-Derivaten (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1988-1997 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photoisomerisation Reactions in Bicyclo[3.2.2]nona-6,8-diene DerivativesFrom the photochemical behavior of suitably substituted derivatives (dicarboxylic ester 3a, dicarboxylic acid 3b, bis(trifluoromethyl)-derivative 3c) it is concluded, that in the bicyclo-[3.2.2]nona-6,8-diene skeleton 1 (n = 3) the [2π + 2π]-Cycloaddition to 2 (n = 3) neither by direct nor by sensitized excitation takes place. Instead 1,3-alkyl shift (3a → 6a) and di-π-methane-rearrangement 3a → 7a, 3c → 8c) are observed. Arguments for this behavior differing from the lower homologues 1 (n = 0, 1, 2) are discussed.
    Notes: Aus dem photochemischen Verhalten geeignet substituierter Derivate (Diester 3a, Dicarbonsäure 3b, Bis-trifluormethyl-Derivat 3c) wird geschlossen, daß im Bicyclo[3.2.2]nona-6,8-dien-Gerüst 1 (n = 3) die [2π + 2π]-Cycloaddition zu 2 (n = 3) weder bei direkter noch bei sensibilisierter Lichtanregung stattfindet. Als Ersatzreaktionen werden 1,3-Alkylverschiebung (3a → 6a) und Di-π-Methanumlagerung (3a → 7a, 3c → 8c) beobachtet. Gründe für dieses von den niedrigeren Homologen 1 (n = 0, 1, 2) abweichende Verhalten werden diskutiert.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19741070621
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    PFT-13C-NMR- und Massenspektren von HeterocyclenNMR-Spektroskopische Studien, 3: 1. und 2. Mitteilung: H. Dürr und W. Bujnoch, Liebigs Ann. Chem. 1973, 1691; H. Dürr und H. Kober, Chem. Ber. 106, 1565 (1973).. - 1,2-Diazaspio[4.4]nonatetraene, Azaindolizine und 3aH-Indazole (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 2037-2049 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: PFT-13C-N.M.R. and Mass Spectra of Heterocycles.  -  1,2-Diazaspiro[4.4]nonatetraenesl Azaindolizines, and 3aH-Indazoles13C n.m.r. spectra obtained by the pulse Fourier transform method of 1,2-diazaspiro[4.4]-nonatetraenes 1, azaindolizines 2, and 3aH-indazoles 3 are described. A combination of highest and lowest field resonances allows an unambigous distinction between 1 and 2. A similiar approach is suggested for 3. Estimated increments from model compounds agree well with the c.m.r. spectra. „Strickspektren“ demonstrate the effect of the substituents on the chemical shift of 1 - 3. The mass spectra of 1 - 3 are discussed briefly.
    Notes: Die mit der Puls-Fourier-Transform-Methode erhaltenen 13C-NMR-Spektren von 1,2- Diazaspiro[4.4]nonatetraenene 1, Azaindolizinen 2 und 3aH-Indazolen 3 werden beschrieben. aus einer Kombination von Höchst-und Tiefstfeld-Resonanzfrequenzen konnten die Strukturen 1 und 2 eindeutig unterschieden werden. Eine entsprechende Analyse wurde für 3 vorgenommen. Inkrementabschätzungen führten zu meist guter Übereinstimmung mit den gemessenen Spektren. Aus den Strichspektren kann der durch die verschiedenen Substituenten hervorgerufene Einfluß auf die chemischen Verschiebung von 1 - 3 werden kurz diskutiert.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19741070626
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    Notiz über die Biogenese von Polyinamiden (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 2120-2122 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070633
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  • 191
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    Substituenteneffekte pericyclischer Reaktionen: Das Cycloheptatrien-Norcaradien-Problem, untersucht an C-7-monosubstituierten VerbindungenVorhergehende Mitteil. in dieser Reihe: l.c.17)). (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 2095-2114 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Substituenteffects in Pericyclic Reactions: The Cycloheptatriene-Norcaradiene-Problem, investigated in C-7-Monosubstituted CompoundsCharacteristic features of the cycloheptatriene-norcaradiene potential curves can be simulated by using methyl cations, which are stabilized by heterofunctional groups and bound to C-7: 1. The potential curve corresponding to low energy cycloheptatriene is realized for the 7-bis(alkylamino)methyl cation 9a 2. Cycloheptatriene and norcaradiene are energetically comparable in the case of the 7-alkoxy(amino)methyl cations. At room temperature 9b - e and 10b - e form a fast dynamic equilibrating system. 3. Norcaradiene 10f comprises the lower minimum of the potential curve for the 7-(1,3-dioxolan-2-ylium) cation. In 10f the substituent is in the exo-position. Using variable temperature 1H-n.m.r., thermodynamic parameters are determined for the equilibria 9b - e ⇋ 10b - e. The influence of C-7-substituents on the cycloheptatriene-norcaradiene equilibrium is discussed and visualized using the MO-model.
    Notes: Methylkationen, stabilisiert durch nachbarständige Alkoxy-oder Alkylaminogruppen und gebunden an C-7, ermöglichen es, drei charakteristische Lagen des Cycloheptatrien-Norcaradien-Gleichgewichtes zu simulieren: 1Mit energieniedrigem Cycloheptatrien-Niveau im 7-Bis(alkylamino)methyl-Kation 9a.2Mit nahezu energiegleichen Cycloheptatrien- und Norcaradien-Grundzuständen in den 7-Alkoxy(amino)methyl-Kationen 9b-e ⇋ 10b - e. 3. Mit energieniedrigem Norcaradien-Grundzustand in der 7-(1,3-Dioxolan-2-ylium)-Verbindung 10f. In 10f ist der Substituent exo-ständig. Thermodynamische Daten der schnellen und reversiblen Gleichgewichte 9b - e ⇋ 10b - e werden bestimmt. Die C-7-Substituentenbeeinflussung des Cycloheptatrien-Norcaradien-Gleichgewichtes wird diskutiert und durch das MO-Modell beschrieben.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19741070631
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  • 192
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    Ein neues Verfahren zur Darstellung von Organylfluorphosphoranen RnPF5-n (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 2169-2175 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: An Easy Way for the Preparation of Organylfluorophosphoranes RnPF5-nOrganylfluorophosphoranes can easily be synthesized by reaction of phosphines or chlorophosphines with CCl4 and HF-donors, especially phenylcarbamoyl fluoride.
    Notes: Eine einfache Synthese der Organylfluorphosphorane beruht auf der Umsetzung von Phosphinen und Chlorphosphinen mit CCl4 und HF-Donatoren, vorzugsweise Phenylcarbamoyl-fluorid.
    Additional Material: 2 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19741070705
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  • 193
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    Zur Reaktion von Cyclopropenonen mit Enaminen, 2. Methylphenyl- und Phenylcyclopropenon und Enamine (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 2215-2237 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Cyclopropenones with enamines, 2. Methylphenyl- and Phenylcyclopropenone and EnaminesThe reaction of methyphenylcyclopropenone (2) with enamines 4a-d and phenycyclopropenone (3) with enamines 4a, c, h at 20°C leads to 2-azoniabicyclo[3.1.0]hex-3-en-3-olates 6, which are isomerized thermally to 2,4-pentadienamides 8. These are also formed directly from 2, 3 and enamines 4 at 80 °C and are accompained in some cases (enamines 4g, h) by β-enaminoketones (5a - c). The constitution and configuration of these „1:1-adducts“ is derived from spectral and chemical evidence. The reaction of 3 with enamines 4 yields as main products „2:1-adducts“ for which the structure of spiro-lactones 20, 21 is assumed on the basis of spectroscopic and chemical data. Some aspects of the mode of formation of these products are discussed.
    Notes: Die Reaktion von Methylphenylcyclopropenon (2) mit den Enaminen 4a - d und Phenyl-cyclopropenon (3) mit den Enaminen 4a, c, h bei 20 C führt zu 2-Azoniabicyclo[3.1.0]hex-3-en-3-olaten 6, die thermisch zu 2,4 -Pentadienamiden 8 isomerisieren. Diese werden bei 80 °C auch direkt aus 2,3 und Enaminen 4 gebildet und sind in einigen Fällen (Enamine 4g, h) von β-Enaminoketonen (5a-c) begleitet. Konstitution und Konfiguration dieser „1:1-Addukte“ wird aus spektroskopischen Kriterien und chemischen Reaktionen abgeleitet. Bei der Umsetzung von 3 mit Enaminen 4 entstehen als Hauptprodukte „2:1-Addukte“ für die aufgrund spektroskopischer und chemischer Befunde die Struktur von Spirolactonen 20, 21 anzunehmen ist. Einige Aspekte zum Bildungsmechanismus dieser Produkte werden diskutiert.
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    URL: http://dx.doi.org/10.1002/cber.19741070708
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    Zur Reaktion von Cyclopropenonen mit Enaminen, 1. Diphenylcyclopropenon und Enamine (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 2186-2214 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reaction of Cyclopropenones with Enamines, 1 Diphenylcyclopropenone and EnaminesDiphenylcyclopropenone (1) reacts with the enamines 9 at 0-20°C to yield the 2-azoniabicyclo[3.1.0]hex-3-en-3-olates 10, whereas at 80°C the main products of the reaction are the 2,4-pentadienamides 25; compounds 10 are isomerized to the amides 25 at 20°C. The structure of the betaines 10 is deduced from their spectral data, their C-protonation (leading to 17), their O-alkylation (leading to 19), and their ring opening reactions with nucleophiles such as water, alcohols, and amines (leading to 20, 23, 24). The structure of the amides 25 is proven by means of spectral data and independent synthesis of the tetrahydro derivatives 26. The reaction of 1 with some enamines 9 produces as by-products the β-enamino ketones 30 and α-amino cyclopentenones 31, which are isomeric with 25. Their structure is confirmed by means of spectra and chemical degradation reactions. Some aspects of the mechanism of the reaction of diphenylcyclopropenone with enamines are discussed on the basis of the constitution of the products 10, 25, 30, and 31.
    Notes: Die Reaktion von Diphenyclyclopropenon (1) mit den Enaminen 9 führt bei 0-20°C zu den 2- Azoniabicyclo[3.1.0]hex-3-en-3-olaten 10, bei 80°C zu den 2,4-Pentadienamiden 25 als Hauptprodukten die Verbindungen 10 werden bei 80°C zu den Amiden 25 isomerisiert. Die Struktur der Betaine 10 wird aus ihren spektroskopischen Daten, ihrer C-Protonierung (zu 17), ihrer O-Alkylierung (zu 19) und ihrer Ringöffnung mit nucleophilen Agentien wie Wasser, Alkoholen und Aminen (zu 20, 23, 24) bewiesen. Der Konstitutionsbeweis der Amide 25 wird über ihre Spektren und über die unabhängige Synthese von Tetrahydroderivaten 26 geführt. Als Nebenprodukte der Reaktion von 1 mit einigen Enaminen 9 werden zu 25 isomere β-Enaminoketone 30 und α-Aminocyclopentenone 31 isoliert. Deren Konstitution wird durch Spektren und Abbaureaktionen gesichert. Aufgrund der ermittelten Konstitutionen 10, 25, 30, 31 werden einige Aspekte des Mechanismus der Reaktion von Diphenylcyclopropenon mit Enaminen erörtert.
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    Die Synthese von Purinnucleosid-6-sulfonaten (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 2284-2294 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Synthesis of Purinenucleoside-6-sulfonates6(1H)-Purinethone-9-(β-D-ribofuranosid) (1), the corresponding 5′-monophosphate 7, and the 5′-triphosphate 8 as well as 2-amino-6(1H)- purinethione-9-(β-D-ribofuranoside) (2) and 2-amino-6(1H)-purinethione-9-(β-D-2′-deoxyribofuranoside) (3) have been converted to the sulfonates 4,9,10,5, and 6 by reaction with sulfite ions in the presence of oxygen. The sulfonates 4 and 5 reacted in aqueous ammonia with good yields to give adenosine and 2,6-diaminopurine-9-(β-D-ribofuranoside), respectively. 4 and 9 react with aziridine to form 6-(1-aziridinyl)purine-9-(β-D-ribofuranoside) (15) and the corresponding 5′-monophosphate 16. 5 and 6 fluoresce with high quantum yields on excitation in the near u. v. It was shown by means of fluorescence spectroscopy, absorption spectroscopy, and comparison with authentic material that irradiation of 1, 2 and 3 by light of the wavelength 235 nm in the presence of oxygen affords the purinenucleoside-6-sulfonates 4, 5 and 6.
    Notes: 6(1H)-Purinthion-9-(β-D-ribofuranosid) (1), das entsprechende 5′-Monophosphat (7) und 5′-Triphosphat (8) sowie 2-Amino-6(1H)-purinthion-9-(β-D-ribofuranosid) (2) und 2-Amino-6(1H)-purinthion-9-(β-D2′-desoxyribofuranosid) (3) wurden durch Reaktion mit Sulfitionen in Gegenwart von Sauerstoff quantitativ in die entsprechenden Sulfonsäurederivate 4,9,10,5,6 übergeführt. Die Sulfonate 4 und 5 ließen sich bei Raumtemperatur mit wäßrigem Ammoniak in guten Ausbeuten zu Adenosin bzw. 2,6-Diaminopurin-9-(β-D-ribofuranosid) umsetzen. 4 und 9 reagierten mit Aziridin zu 6-(1-Aziridinyl)purin-9-(β-Dribofuranosid) (15) bzw. dem 5′-Monophosphat 16. 5 und 6 fluoreszieren mit hoher Quantenausbeute im langwelligen ultravioletten Licht. Mit Hilfe der Fluoreszenzspektroskopie, Absorptions-spektroskopie und durch Vergleich mit authentischem Material konnte die Bildung der Purinnucleosid-6-sulfonate 4, 5 und 6 auch bei der Bestrahlung von 1, 2 und 3 mit Licht der Wellenlänge 325 nm in Gegenwart von Sauerstoff nachgewiesen werden.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19741070713
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    2-Propyl-cis-perhydrochinolin-5α-ol (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 2326-2328 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 2-Propyl-cis-perhydroquinolin-5α-olReaction of 1,3-cyclohexanedione with 1-chloro-3-hexanone (2), followed by reductive amination yields 2-propyl-1,2,3,4,5,6,7,8-octahydro-5-quinolinon (4). On hydrogenation with Pt in acetic acid 2-propyl-cis-perhydroquinolin-5α-ol (5) is obtained.
    Notes: Ausgehend von 1,3-Cyclohexandion wurde durch Umsetzung mit 1-Chlor-3-hexanon (2) und nachfolgende reduktive Aminierung das 2-Propyl-1,2,3,4,5,6,7,8-octahydro-5-chinolinon (4) erhalten. Hieraus entsteht bei der Hydrierung mit Pt in Eisessig 2-Propyl-cis-perhydrochinolin-5α-ol (5).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070717
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  • 197
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    Electronic Resource
    Studien über elektronegativ substituierte Thiocarbonylverbindungen, 2. Trithiocarbonat-S,S-dioxide (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 2345-2361 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Studies of Electron-Depleted Thiocarbonyl Compounds, 2. Trithiocarbonate S,S-DioxidesEleven trithiocarbonate S,S-dioxides 1 were prepared by treatment of chlorodithioformates with sulfinic acid salts and their properties investigated. In the reaction of methyl chlorodithioformate with sodium methanesulfinate, methyl (methylsulfonyl)(methylthio)methyl trithiocarbonate (4a) is formed instead of the expected 1. Compounds 4 can also be obtained by reduction of 1 with sulfinates, thiophenols, or tetrabutylammonium borohydride. Sodium diethyl methylmalonate is thioacylated by S′-phenyl S-p-tolyl trithiocarbonate S,S-dioxide (1i) to yield diethyl methyl(phenylthiothiocarbonyl)malonate(13), while the less bulky phenyllithium attacks 1i in a nucleophilic manner at the thiono sulfur to yield S′,S″-diphenyl S-p-tolyl trithioorthoformate S,S-dioxide (15). Inverse addition of Grignard solutions to 1 produces the 1-sulfonyl -1,2,2-trithioethylenes 19.
    Notes: Durch Umsetzung von Chlordithioformiaten mit Sulfinsäuresalzen wurden elf Trithiocarbonat-S.S-dioxide 1 dargestellt und auf ihre Eigenschaften untersucht. Bei der Umsetzung von Methyl-chlordithioformiat mit Natrium-methansulfinat bildet sich statt des erwarteten 1 Methyl-[(methylsulfonyl)(methylthio)methyl]-trithiocarbonat (4a). Die Verbindungen 4 erhält man auch bei der Reduktion von 1 mit Sulfinaten, Thiophenolen oder Tetrabutylammoniumboranat. Natrium-methylmalonsäure-diäthylester wird von S′-Phenyl-S-p-tolyl-trithiocarbonat-S,S-dioxid (1i) zu Methy(phenylthiothiocarbonyl)malonsäure-diäthylester (13) thioacyliert, während das weniger sperrige Phenyllithium 1i nucleophil am Thionschwefel unter Bildung von S′.S″-Diphenyl-S-p-tolyl-trithioorthoformiat-S,S-dioxid (15) angreift. Inverse Addition von Grignard -Verbindungen an 1 führt zu den 1-Sulfonyl-1,2,2-trithioäthylenen 19.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070720
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  • 198
    Electronic Resource
    Electronic Resource
    Heterocyclische Dicarbonsäureester, III. Zur Reaktion von 4,5-Dihydro -2,3-furandicarbonsäure-dimethylestern mit 1,2-Diaminen.  -  Synthese von 3-(5-Alkyl -2-oxotetrahydro-3-furanyliden)-2-chinoxalinonen, -2-pyrazinonen und -1,4-diazepin-2-onen (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 2397-2404 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Heterocyclic Dicarboxylic Acid Esters, III. Reaction of Dimethyl 4,5-Dihydro-2,3-furandicarboxylates with 1,2-Diamines.  -  Synthesis of 3-(5-Alkyl-2-2oxotetrahydro-3-furanylidene)-2-quinoxalinones, -2-pyrazinones, and -1,4-diazepine-2-onesTreatment of the dihydrofurandicarboxylic acid esters 4a-c with 1.2-diamines does not result in normal ester aminolysis but in ring cleavage followed by lactonization. According to the diamine used the quinoxalinones 14, 15a-c, the pyrazinones 11-c, and the diazepinones 16a, c are obtained. The independent synthesis of the compounds 11a, 14a, 15a by condensation of the different diamines with α-ethoxalyl-γ-butyrolactone as well as the tabulated i. r. and n. m. r. data confirm the proposed structures.
    Notes: Dihydrofurandicarbonsäureester vom Typ 4a-c reagieren mit 1,2-Diaminen nicht im Sinne einer normalen zweifachen Ester-Aminolyse, sondern unter Ringöffnung und anschließender Lactonisierung. Entsprechend dem eingesetzten Diamin erhält man die Chinoxalinone 14.15a-c, die Pyrazinone 11a-c sowie die Diazepinone 16a, c. Die unabhängigen Synthesen der jeweiligen Grundkörper 11a, 14a, 15a durch Kondensation der verschiedenen Diamine mit α-Äthoxalyl-γ-butyrolacton, wie auch die aufgeführten IR- und NMR-Daten bestätigen die angenommenen Strukturen.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070723
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  • 199
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    Electronic Resource
    Ungewöhnlicher Verlauf einer Acetalhydrolyse bei einer Homotropiliden-Synthese (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 3053-3069 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Unusual Course of an Acetal Hydrolysis during a Synthesis of HomotropilideneAcetals 3a-c are synthesized by Diels-Alder reaction of cyclopropene and 1-methyleyclopropene with tetrachlorocyclopentadienone acetals. Dechlorination of the adducts leads to the acetals 4a-c; their reaction with diazomethane yields 8a-c. Hydrolysing the acetals 8a, b the ketone 9 (35%) and a rearranged product 10 (65%) are formed. The hydrolysis of the acetal 8c gives only the rearranged products 11a-c. The constitution and the stereochemistry of all new products is confirmed by 1H and 13C n.m.r. spectroscopy, in the case of alcohol 11a by using Eu(fod)3 as a shift reagent. The mechanism of the hydrolysis is explained by the nature of the intermediate carbenium-oxonium ion and its steric shielding by the exo-cyclopropane ring.
    Notes: Durch Diels-Alder-Reaktion von Cyclopropen bzw. 1-Methylcyclopropen mit Tetrachlor-cyclopentadienon-acetalen werden die Acetale 3a-c erhalten. Die Dechlorierung der Addukte liefert die Acetale 4a-c, deren Homologisierung mit Diazomethan zu den tetracyclischen Acetalen 8a-c führt. Durch Hydrolyse der Acetale 8a, b entsteht zu 35% das Keton 9 und zu 65% ein Umlagerungsprodukt der Struktur 10. Je nach den angewandten Bedingungen lassen sich bei der Hydrolyse des Acetals 8c nur Umlagerungsprodukte 11a-c isolieren. Die Konstitution und Stereochemie der neuen Verbindungen wird durch 1H- und 13C-NMR-Spektroskopie, z. T. unter Anwendung von Lanthanoiden-Shift-Reagenzien, gesichert. Der Hydrolysenmechanismus wird über das intermediäre Carbenium-Oxonium-Ion und dessen sterische Abschirmung durch den exo-Dreiring erklärt.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070928
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  • 200
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    Electronic Resource
    Beiträge zur Chemie des Bors, LXVII. Silaborazine aus Cyclosilazanen (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 3113-3120 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Chemistry of Boron, LXVII. Silaborazines from CyclosilazanesPhenyldichloroborane reacts with [(CH3)2SiNH]3 (5) to yield the disilaboranine 8, the monosilaborazine 7, and/or B,B′, B″-triphenylborazine (9), depending on the ratio of the reactants. Reaction with octamethylcyclotetrasilazane, [(CH3)2SiNH]4 (12), in a 1:1 molar ratio leads to NH4Cl, 8, and a polymer. Product analysis shows that only part of 8is formed by direct SiN-cleavage, the other part results from a substitution leading to NH4Cl.
    Notes: Phenylbordichlorid reagiert je nach Molverhältnis mit [(CH3)2SiNH]3 (5) zum Disilaborazin 8, Monosilaborazin 7und/oder B,B′, B″-Triphenylborazin (9). Bei der Umsetzung mit Octamethylcyclotetrasilazan, [(CH3)2SINH] 4 (12), im Molverhältnis 1:1 entstehen NH4Cl, 8 und Polymere. Aus der Stoffbilanz folgt, daß nur ein Teil von 8über direkte Silazanspaltung entstehen Kann; der andere ist die Folge einer zu NH4Cl führenden Substitutionsreaktion.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070932
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