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  • 1970-1974  (4,058)
  • 1965-1969  (4,264)
  • Inorganic Chemistry  (8,062)
  • Electron Microscopy
  • Insulin
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  • 1
    Electronic Resource
    Electronic Resource
    Elektronenmikroskopische Befunde am Ganglion spirale und Cortischen Organ des Meerschweinchens nach Glutaraldehyd- und Osmiumfixation und Anwendung verschiedener Fixationstechniken (1974)
    Springer
    European archives of oto-rhino-laryngology and head & neck 208 (1974), S. 257-265 
    Details
    ISSN: 1434-4726
    Keywords: Spiral ganglion and Organ of Corti ; Electron Microscopy ; Influence of Different Fixatives and Fixation Methods
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Das Ganglion spirale und Cortische Organ des Meerschweinchens wurden nach Osmium- und kombinierter Glutaraldehyd-Osmiumfixation sowie Anwendung verschiedener Fixationsmethoden elektronenmikroskopisch untersucht. Die Strukturen des Cortischen Organs wurden hierbei nicht wesentlich beeinflußt. Am Ganglion spirale ergaben sich Unterschiede im Aufbau der Myelinhüllen der Ganglienzellen. Es wird diskutiert, daß es sich beim semikompakten Myelin um ein Artefakt der Osmiumfixation handelt und daß Glutaraldehyd den Aufbau der Myelinhüllen im Bereich der Spiralganglienzellen naturgetreuer wiedergibt als Osmium.
    Notes: Summary We have been examining with the electron microscope the spiral ganglion and the organ of corti in guinea pigs, using osmium and a combined glutaraldehyde-osmiumfixation together with various fixation techniques. The structures of the organ of corti were not considerably effected. Differences in the structure of the myelin sheets of ganglion cells were found in the spiral ganglion. Presumably the semicompact myelin represents an artefakt after osmium-fixation, glutaraldehyde being able to demonstrate clearer the structure of the myelin sheets on spiral ganglion cells compared to osmium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02438984
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  • 2
    Electronic Resource
    Electronic Resource
    The short-term effects of high doses of ethylene-1-hydroxy-1, 1-diphosphonate upon early dentin formation (1974)
    Springer
    Calcified tissue international 16 (1974), S. 109-127 
    Details
    ISSN: 1432-0827
    Keywords: Dentinogenesis ; Diphosphonates ; Calcification ; Collagen ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract The effects of high doses of ethylene-1-hydroxy-1,1-diphosphonate (EHDP) were investigated at the light microscopic and subcellular level. The administration of EHDP at a concentration of 7.5–10 mg P/kg body weight/day over a short period of time resulted in complete inhibition of crystal formation in predentin and pre-enamel. An increased predentin width was observed and within newly-formed predentin areas the formation ofcollagen fibrils was grossly disturbed. In addition, fine precipitates appeared in the ground substance. The presence of unusual thread-like elements within specific bodies in the cytoplasm of the odontoblastic processes may be indicative of an interference by EHDP in e.g. the synthesis of precollagen. The possibility of an inhibition by EHDP of the extracellular aggregation of collagen molecules is also discussed. EHDP further inhibited crystal formation within dentinal globules. Functioning ameloblasts were grossly affected in EHDP-treated rats, and it is suggested that this is related to an inhibition of crystal formation in pre-enamel.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02008217
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  • 3
    Electronic Resource
    Electronic Resource
    Cellular breakdown within the arterial wall (1974)
    Springer
    Virchows Archiv 364 (1974), S. 111-127 
    Details
    ISSN: 1432-2307
    Keywords: Electron Microscopy ; Coronary Arteries ; Atherosclerosis ; Aging ; Smooth Muscle
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The coronary arteries were studied by electron microscopy in normal rats weighing 65 to 535 gm; fixation was accomplished by perfusion for 20 min at 110–130 mm Hg. In rats of all ages (but especially in the oldest) the arterial wall contained deposits of abnormal intercellular material, consisting of granules, vesicles, myelin figures and other debris. These deposits were present in the intima and media, but rare in the adventitia; there was suggestive evidence that medial cells phagocytized some of the material. The adventitia was characterized by 1–4 layers of cells with extremely thin protoplasmic expansions wrapped around the vessel (“veil cells”) and containing lysosome-like bodies as well as phagosomes. These findings, taken as a whole, suggest the following sequence of events. During normal life, the media produces cellular debris, by cell death as well as by fragmentation of cellular processes; part of these debris are phagocytized by smooth muscle cells, part diffuse outward to the adventitia where they are taken up by specialized cells (the “veil cells”). However, due to relative inadequacy of phagocytosis in the media, the debris continue to accumulate and form intercellular deposits that increase with age. It is possible that this natural phenomenon may by itself set a maximal limit to the life-span of the arterial wall.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01230861
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  • 4
    Electronic Resource
    Electronic Resource
    Zur Pathomorphologie der sogenannten Epinephrin-Myokarditis nach Gabe von Hypertensin (1974)
    Springer
    Virchows Archiv 363 (1974), S. 249-258 
    Details
    ISSN: 1432-2307
    Keywords: Hypertensin (Angiotensin) ; Catecholamins ; So-Called Epinephrine Myocarditis ; Rat Heart ; Optical Microscopy ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Pathomorpliological comparative studies on structural damage to rat cardiac muscle following administration of hypertensin and arterenol, with and without pretreatment with reserpine to empty the catecholamine reserves were performed. The question is whether and to what degree angiotensin induced cardiac damage, which is viewed microscopically as the so-called epinephrine myocarditis, can be regarded as an indirect catecholamine effect. The following could be deduced: 1. Hypertensin causes a damage pattern similar to that of arterenol as seen under the light microscope and corresponds to the so-called epinephrine myocarditis. 2. The electron microscope demonstrates definite differences in the pattern of damage to the myocardium: hypertensin affects primarily the mitochondria, while arterenol affects the myofibrils. 3. Hypertensin and arterenol damage mainly the subendocardial tissue of the left heart: hypertensin affects more the region of the base of the left ventricle, arterenol more the region of the left ventricle apex. 4. Pretreatment with reserpine blocks the damaging effects of hypertensin in the rat heart for 12 hours. After 24 hours the full picture of the damage pattern has reappeared. Arterenol is lethal to animals pretreated with reserpine. 5. The pathogenesis of the damaging effects of hypertensin on rat cardiac muscle is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00432805
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  • 5
    Electronic Resource
    Electronic Resource
    An analysis of the ultrastructural findings in infantile neuroaxonal dystrophy (Seitelberger's disease) (1974)
    Springer
    Acta neuropathologica 27 (1974), S. 201-213 
    Details
    ISSN: 1432-0533
    Keywords: Infantile Neuroaxonal Dystrophy ; Spheroids ; Perikaryon ; Electron Microscopy ; Membranous Profiles ; Dense Bodies ; Protein Syntheses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Electron microscopic findings of a cortical biopsy from a four-year-old child suffering from muscular weakness and psychomotor retardation are presented. Morphological evidence obtained in this study suggests a unique pathogenetic mechanism underlying INAD. The spheroids appear to be caused by an accumulation of a macromolecular substance synthesized in the neuron and transported to the nerve endings. The abnormal substance initially takes the form of an amorphous material, it eventually aggregates into highly characteristic angulated membranous profiles. The selective involvement of the nerve endings, synapses and motor end plates in this disease suggests a derangement of the metabolic pathway in the synthesis or packaging of the neurotransmitters or their receptors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687630
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  • 6
    Electronic Resource
    Electronic Resource
    Massive congenital intracranial teratoma (1974)
    Springer
    Acta neuropathologica 30 (1974), S. 271-276 
    Details
    ISSN: 1432-0533
    Keywords: Intracranial Teratoma ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A massive congenital benign teratoma grossly replacing the cerebral hemispheres has been examined by light and electron microscopy. The tumor contained tissues derived from all three germ layers. The cerebellum showed morphological features suggesting a state of maturation equivalent to that of 20 to 25 weeks of gestation. The tumor is discussed in the light of present theories on the pathogenesis of teratomas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00688927
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  • 7
    Electronic Resource
    Electronic Resource
    Oncocytes in the anterior lobe of the human pituitary gland (1974)
    Springer
    Acta neuropathologica 27 (1974), S. 43-53 
    Details
    ISSN: 1432-0533
    Keywords: Oncocytes ; Adenohypophysis ; Pituitary Adenoma ; Secretory Granules ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A light and electron microscopic study was undertaken on 3 surgically removed non-tumorous adenohypophyses and 16 pituitary adenomas. Numerous oncocytes have been found in 2 non-tumorous adenohypophyses and in 6 pituitary adenomas including 1 chromophobe adenoma which was composed almost exclusively of oncocytes. Thus, it seems that the occurrence of oncocytes in the anterior pituitary cannot be considered a rare finding. The distinctive feature of oncocytes is the abundance of mitochondria in their cytoplasm. This alteration can be so extensive that the entire cytoplasm is filled with mitochondria leaving only a small area for the remaining cytoplasmic organelles. Oncocytes arise from adenohypophysial cells. This transformation is gradual and is not restricted to one particular cell type. In the early phases of development of oncocytes the secretory granules are well preserved. Thus, hormone secretion is presumably maintained. It seems conceivable, however, that in the more advanced phases of evolution of oncocytes, when the secretory granules decrease in number, hormone production is diminished or stopped. Further investigations are, however, required to elucidate in detail the functional activity of oncocytes. It remains to be established whether mitochondrial accumulation is principally due to increased formation or delayed breakdown. As some mitochondria show signs indicating division it appears that multiplication of mitochondria is the underlying mechanism resulting in their significant increase. However, the possibility cannot be excluded that the life span of mitochondria is prolonged and mitochondrial longevity plays an important role in causing transformation of adenohypophysiocytes into oncocytes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687239
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  • 8
    Electronic Resource
    Electronic Resource
    Progressive multifocal leukoencephalopathy with paramyxovirus-like structures, Hirano bodies and neurofibrillary tangles (1974)
    Springer
    Acta neuropathologica 27 (1974), S. 277-288 
    Details
    ISSN: 1432-0533
    Keywords: Progressive Multifocal Leukoencephalopathy ; Hirano Bodies ; Papova Virus ; Paramyxovirus-like ; Nuclear Bodies ; Electron Microscopy ; Neurofibrillary Tangles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We have identified three structures that have not previously been reported in electron microscopic examinations of brain from patients with PML: 1. coiled nuclear bodies that may possibly represent tubular paramyxovirus nucleocapsids, 2. Hirano bodies and 3. Neurofibrillary tangles. The paramyxovirus-like material is interesting in view of reports of a transition between nuclear bodies and tubular paramyxovirus nucleocapsids and because of a possible interaction between syncytiogenic paramyxoviruses and Papova viruses in the pathogenesis of SSPE and PML. A study of the Hirano bodies in this case, taken in conjunction with the findings of others leads us to believe that these structures are formed from an overgrowth of neurofilaments. The presence of tangled masses of neurofilaments in the processes of neurons also seen in the present case is consistent with this hypothesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00690693
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  • 9
    Electronic Resource
    Electronic Resource
    Acute hexachlorophene encephalopathy: Clinico-neuropathological correlation (1974)
    Springer
    Acta neuropathologica 28 (1974), S. 93-103 
    Details
    ISSN: 1432-0533
    Keywords: Hexachlorophene Intoxication ; Toxic Encephalopathy ; Optic Nerve Necrosis ; Cerebral Edema ; Status Spongiosus ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary This is the first report of neuropathologic findings following oral ingestion of hexachlorophene in the human. The patient was a 7 year old boy who accidentally ingested 45 ml (approx.) of pHisoHex (hexachlorophene).Toxic reactions included nausea, vomiting, anorexia, diarrhea, decrease in visual acuity, blurred vision blindness, somnolence and disorientation. He developed cardiac arrhythmia, fever, isoelectric EEG and finally respiratory and cardiac arrest 61 h after admission. Autopsy findings showed interstitial myocarditis, pneumonitis and acute bronchiolitis. The brain was edematous. Light microscopy revealed mild diffuse vacuolization of white matter, occasional neuronal degeneration, most prominent on deepest layers of the visual cortex. Disintegration of myelin sheaths and necrosis of axon cylinders were present throughoutoptic pathways. Electron microscopy revealed large, empty extracellular and intramyelinic spaces formed by splitting and separation of the myelin lamellae. These changes are known to occur in experimental animals intoxicated with hexachlorophene, triethyltin, isonicotinic acid hydrazide and cuprizone. However, with respect to hexachlorophene, the localization of lesions to be optic pathways appears to be dependent upon an oral route of administration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00710320
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  • 10
    Electronic Resource
    Electronic Resource
    Infantile neuroaxonal dystrophy or Seitelberger's disease (1974)
    Springer
    Acta neuropathologica 28 (1974), S. 261-267 
    Details
    ISSN: 1432-0533
    Keywords: Neuroaxonal Dystrophy ; Infantile Autonomi Nervous System ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The autonomic nervous system is studied by electron microscopy for the first time in two siblings born of North African consanguineous parents and affected by infantile neuroaxonal dystrophy. The changes already reported in dystrophic axons of the central and peripheral nervous system, are seen in the myenteric plexus of rectum mucosa. The authors stress the diffuse involvement of the nervous tissue in this degenerative disorder of still unknown nature.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00719031
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  • 11
    Electronic Resource
    Electronic Resource
    Elektronenoptische und enzymhistochemische Vergleichsuntersuchungen an Kraniopharyngiomen und ihren Gewebekulturen (1974)
    Springer
    Acta neuropathologica 28 (1974), S. 331-341 
    Details
    ISSN: 1432-0533
    Keywords: Craniopharyngioma ; Tissue Culture ; Electron Microscopy ; Enzyme Histochemistry ; Keratine ; Enamel ; Rosenthal Fibers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Electron optical and enzyme histochemical investigations carried out on four craniopharyngiomas and their tissue cultures demonstrated that the tumour elements are keratinizing epithelial cells, plenty of tonofilaments, glycogen granules, mitochondria and desmosomes. Their ultrastructural and histochemical characteristics are the same in every part of the tumour (solid; cystic; “adamantinoma-like”). In the keratinizing cells, the reactions for non-specific esterases were high positive. The ultrastructural characteristics of the tumour cells grownin vitro are the same as thosein situ; the cells remain attached to one another by desmosomes and retain their capacity to produce keratine. This therefore seems to be a primary characteristic of the tumour cells and not a secondary dysmetabolic disturbance. Calcium was found onlyin situ. That the tumour cells may produce enamelin situ seems to be possible, but it could not be confirmed with certainty. The glial proliferation which is always presentin situ, is reactive and not neoplastic; thein vitro new built cell colonies consist only of epithelial elements.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00685287
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  • 12
    Electronic Resource
    Electronic Resource
    Fine structural localisation of acid phosphatase in neural tumours induced by N-ethyl-N-nitrosourea in rats (1974)
    Springer
    Acta neuropathologica 29 (1974), S. 45-55 
    Details
    ISSN: 1432-0533
    Keywords: Experimental Neural Tumours ; Ethylnitrosourea ; Electron Microscopy ; Lysosomes ; Acid Phosphatase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A single intravenous injection of 30 mg of N-ethyl-N-nitrosourea per kg of body weight was administered to pregnant BD-IX rats on the 15th day of gestation. The neural tumours which developed in 97.5% of the offspring were gliomas and schwannomas. The demonstration of acid phosphatase in the neoplastic and reacting cells of these tumours was carried out at fine structural level. The enzyme activity was localised in lysosomes and in the innermost cisternae of the Golgi complexes. High acid phosphatase activity was related not only to degeneration, necrosis and phagocytosis but also to cellular differentiation and anaplasia.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00684390
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  • 13
    Electronic Resource
    Electronic Resource
    Electron microscopic study of neurofibrillary tangles in Steele-Richardson-Olszewski syndrome (1974)
    Springer
    Acta neuropathologica 29 (1974), S. 175-179 
    Details
    ISSN: 1432-0533
    Keywords: Steele-Richardson-Olszewski Syndrome ; Progressive Supranuclear Palsy ; Neurofibrillary Tangles ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The neurofibrillary tangles found in the neurons of a case of Steele-Richardson-Olszewski syndrome were studied by electron microscopy. Both the flame-shaped and globose type of tangles were present. The neurofibrillary tangles were composed of bundles of straight tubules measuring approximately 150 Å in diameter. This ultrastructural appearance of the tangles in Steele-Richardson-Olszewski syndrome is different from the appearance of tangles found in other neurological disorders and is probably indicative of intraneuronal accumulation of a new type of fibrous protein.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00684775
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  • 14
    Electronic Resource
    Electronic Resource
    Ultrastructure of the sural nerve in chronic polyneuropathy associated with Adie's syndrome (1974)
    Springer
    Acta neuropathologica 29 (1974), S. 181-186 
    Details
    ISSN: 1432-0533
    Keywords: Polyneuropathy Associated with Adie's Syndrome ; Sural Nerve ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The sural nerve of a woman of 35 with chronic polyneuropathy and Adie's syndrome was examined by electron microscopy. Myelinated nerve fibres were absent and there was marked reduction in the number of unmyelinated fibres. Onion bulb formation was not observed. Collagen fibres occupied the intercellular spaces.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00684776
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  • 15
    Electronic Resource
    Electronic Resource
    The fine structural localisation of thiamine pyrophosphatase and adenosine triphosphatase in neural tumours induced by N-ethyl-N-nitrosourea in rats (1974)
    Springer
    Acta neuropathologica 29 (1974), S. 199-209 
    Details
    ISSN: 1432-0533
    Keywords: Experimental Neural Tumours ; Ethylnitrosourea ; Electron Microscopy ; Thiamine Pyrophosphatase ; Adenosine Triphosphatase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The fine structural localisation of thiamine pyrophosphatase and adenosine triphosphatase was carried out in gliomas and schwannomas induced transplacentally by N-ethyl-N-nitrosourea. The activity of thiamine pyrophosphatase was observed in the Golgi complexes and appeared to be directly related to cellular differentiation and reactive changes. The Mg2+-dependent adenosine triphosphatase was localised at the cell membrane, in the pinocytotic vesicles of various cells and in the basement membrane of some capillaries. This enzyme, showing high activity in differentiated cells, indicated the activity of membrane-bound cellular transport.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00685255
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  • 16
    Electronic Resource
    Electronic Resource
    Virus-like particles in brain tumours induced by N-ethyl-N-nitrosourea in rats (1974)
    Springer
    Acta neuropathologica 29 (1974), S. 211-222 
    Details
    ISSN: 1432-0533
    Keywords: Experimental Gliomas ; Ethylnitrosourea ; Electron Microscopy ; Virus-like Particles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Two unusual, intracytoplasmic structures, resembling viruses, are described in experimental gliomas which were induced transplacentally on the 15th day of gestation in BD-IX rats by a single intravenous injection of 30 mg of N-ethyl-N-nitrosourea per kg of body weight. These structures are tubules within the lumen of the endoplasmic reticulum and large coated vesicles in the Golgi region. The tubules are of indeterminate length and have inner and outer walls of 9–11 nm and 20–22 nm respectively. The large coated vesicles are 80–90 nm in diameter and their outer surface is covered by regular, equidistant spikes of 12–15 nm in length. The vesicles are closely related to the Golgi complexes, from which they appear to originate. The intracisternal tubules and large coated vesicles share certain morphological features both with viruses and with normal cell organelles. The origin and significance of these structures are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00685256
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  • 17
    Electronic Resource
    Electronic Resource
    Cellular monstrosity in embryonic neuronal neoplasm produced by human adenovirus in rats (1974)
    Springer
    Acta neuropathologica 30 (1974), S. 315-328 
    Details
    ISSN: 1432-0533
    Keywords: Human Adenovirus Type 12 ; Sprague-Dawley Rats ; Intracerebral Inoculation ; Medulloepitheliomatous Neoplasm ; Giant Tumor Cells ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Solid medullary brain and spinal cord neoplasms developed in all 10 offspring of an outbred Sprague-Dawley rat, between 37 and 99 days after a single postnatal (within 24 hrs) inoculation of 0.05 ml of human adenovirus type 12, 103.5–104.5 TCID50 HeLa cells/0.1 ml in the left frontal lobe. Seven rats developed multicentric neoplasms in both hemispheres and in peri-aqueductal areas of the brain stem, one of which was associated with an incipient spinal cord tumor in the sacral segment. One rat developed a solid tumor involving the right parieto-occipital region. The remaining two cases were solid spinal cord tumors arising from the dorsal half of the thoracolumbar segments. The remarkably uniform microscopic appearance was designated as a counterpart of human embryonic neuronal neoplasms. Characteristic neuronal and multinucleated giant cells emerged throughout the tumor tissue with argentaffine, neurofibril-like cytoplasmic expansions and a unique cilium (a 9+0 pattern of tubules) associated with a pair of centrioles. This cilium morphology was also a hallmark of the majority of tumor cells that formed characteristic pseudorosettes. The occasional emergence of two sets of cilia and centrioles in monstrous cells suggested probable modes of cytogenesis in relation to cessation of abnormal cell division.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00697014
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  • 18
    Electronic Resource
    Electronic Resource
    Late changes in sciatic nerve of rats after a small dose of methyl methylmercury sulfide (1974)
    Springer
    Acta neuropathologica 30 (1974), S. 33-41 
    Details
    ISSN: 1432-0533
    Keywords: Organic Mercury Compound ; Late Pathological Changes in Peripheral Nerves ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Wistar strain of male rats of 100–110 g were used, 5 for an experimental and 5 for control group. 1 mg of organic mercury (methyl methylmercuric sulfide: CH3HgSCH3) was given by mouth each day for 10 days (total dose 9–10 mg) to the experimental group. 600 days afterwards the experimental and control rats were killed. Only the peripheral nerves showed changes, small myelinated nerve fibres with thick myelin sheaths in groups. Around these fibres occurred extremely small myelinated nerve fibres and isolated large unmyelinated fibres, and appeared to be regenerated fibres. Destruction of myelin sheaths and cavity formation in the axons were observed in these fibres. The changes in the axons were remarkable at the nodes of Ranvier.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00685320
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  • 19
    Electronic Resource
    Electronic Resource
    Familial ataxia of the rabbit Sawin-Anders type (1974)
    Springer
    Acta neuropathologica 30 (1974), S. 11-24 
    Details
    ISSN: 1432-0533
    Keywords: Ataxia ; Rabbit ; Degeneration ; Cochlear Nuclei ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary This hereditary animal ataxia is selective in its sites of involvement within the nervous system, which include principally the central cerebellar, vestibular and cochlear nuclei. Ultrastructural detail has been described for central cerebellar and vestibular nuclei. Herein the cochlear complex of 18 rabbits with this ataxic condition (ax/ax from the strain AX of the Jackson Laboratory) have been examined. The gene is a lethal one, but the animals were used before they became moribund and between 7 and 57 days after the onset of symptoms. By light microscopy nine cell types (Osen, 1969a, b; 1970) have been identified in the cochlear nuclei of the cat. That distribution can also be identified in electron micrographs of rabbit cochlear nuclei, providing there is a singular opportunity to compare cellular vulnerabilities within the ataxic condition, and establish the principal features of associated neuropil alterations. The cochlear nuclei, cerebellar cortex and central nuclei, and the vestibular nuclei, arise from the ependyma of the rhombic lip of the fourth ventricle, making them close allies in their genetic origins. Pathological alterations were evident in scattered neurons from all nuclear sources by 7–15 days following symptom onset. At 15 days the number of altered neurons evident in electronmicrographs had increased markedly, cells becoming involved at a more rapid pace than those already affected could be removed. Much glycogen is evident from 7 days onwards in both neuropil and neurons. It occurs in considerable amounts in astrocytic processes and less abundantly in endbulbs and somata. By 20 to 25 days spongioform changes in neuropil are prominent, and thereafter the extracellular spaces coalesce to produce a lacunar appearance showing little glycogen. It would appear, therefore, that all neuron types, the endbulbs, and the astrocytic processes are markedly involved simultaneously in the spongioform transformation which features this type of ataxia. Involvement of cochlear nuclei only differs in pathological detail from that found at the other involved sites, and the differences seen relate principally to the architectonics of the nuclei, including size and density of the packing of contained elements.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00685318
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  • 20
    Electronic Resource
    Electronic Resource
    Studies on GM1-gangliosidosis, type II (1974)
    Springer
    Acta neuropathologica 30 (1974), S. 155-173 
    Details
    ISSN: 1432-0533
    Keywords: GM1-Gangliosidosis ; Glycoproteins ; β-Galactosidase ; Lysosomal Disease ; Electron Microscopy ; Genetics of GM1-Gangliosidosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Post-mortem studies on a 6-year old boy with GM1-gangliosidosis, Type II revealed no evidence of accumulation of residual bodies nor of gangliosides or glycoproteins in liver and spleen. In brain tissue the ganglioside GM1 accounted for 70% of the ganglioside fraction and ganglioside-NANA was increased 3.6 fold over controls. In addition, the brain tissue contained large amounts of glycoprotein, glycoprotein derived galactose being increased 2.5 times. The neuronal accumulation of tertiary lysosomes exhibited a characteristic distributional pattern: in general the large neuronal perikarya were more consistently involved with the exception of the motor cells of the cranial nerve nuclei, III, IV, and VI. In addition to characteristic MCB's, the nerve cells contained residual bodies with a granulo-floccular matrix, presumed to represent glycoproteins. The distribution of the mutant gene was studied among 30 blood relatives of the proband at risk and 6 carriers could be ascertained on the basis of a reduced leukocytic β-galactosidase activity. The partly purified enzyme from the patient's liver revealed 20% activity as compared to that of normal controls. All three fractions obtained by DEAE cellulose column chromatography exhibited markedly reduced activity at pH 3.6, but nearly normal activity at pH 6.6. The reduced activity corresponded to the B component of the enzyme as shown by electrophoretic separation. It is pointed out that this case cannot be diagnosed as “generalized gangliosidosis” for the process of ganglioside accumulation was restricted to nervous tissue.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00685440
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  • 21
    Electronic Resource
    Electronic Resource
    Lafora's disease (1974)
    Springer
    Acta neuropathologica 30 (1974), S. 189-196 
    Details
    ISSN: 1432-0533
    Keywords: Lafore Bodies ; Polysaccharidosis ; Electron Microscopy ; Epilepsia ; Histochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Cerebral biopsies of three patients aged 22, 18 and 16 years with myoclonic epilepsy contained Lafory bodies. Two were a brother and sister of consanguineous parents. The Lafora bodies occurred in most neurons but not in glial cells. The ultrastructure of these bodies showed a fibrillar and granular material in the perikaryon and neuropile. In some neurons small Lafora bodies were delimited by a double membrane, suggesting that in early phases they have a membrene which disappears when they become more developed. Other non-specific neuron alterations are described. One of the cases presented in the liver PAS positive bodies of a structure different from the Lafora bodies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00688920
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  • 22
    Electronic Resource
    Electronic Resource
    Intra-axonal bacilli in lepromatous leprosy (1974)
    Springer
    Acta neuropathologica 27 (1974), S. 1-10 
    Details
    ISSN: 1432-0533
    Keywords: Leprosy ; Lepromatous ; Axonal Bacillation ; Schwann Cells ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary M. leprae bacilli in nerves of 3 patients with lepromatous leprosy were found in the axoplasm of myelinated and unmyelinated nerve fibers. Axonal bacillation occurred in as much as 2% of myelinated axons. Bacilli within Schwann cells were a more common finding in lepromatous leprosy that intra-axonal bacilli. Intra-axonal bacillation probably represents a late stage phenomenon in lepromatous leprosy. Intra-axonal bacilli may contribute to the dissemination of leprosy by migration of bacilli within the axon, and may contribute directly to nerve fiber destruction.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687235
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  • 23
    Electronic Resource
    Electronic Resource
    An electron microscope study of chronic median nerve compression in the guinea-pig (1974)
    Springer
    Acta neuropathologica 27 (1974), S. 69-82 
    Details
    ISSN: 1432-0533
    Keywords: Chronic Nerve Compression ; Median Nerve ; Guinea-Pig ; Electron Microscopy ; Degeneration ; Regeneration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In guinea-pigs with chronic median nerve compression at the wrist the electron microscopic changes at level of the lesion and both proximal and distal to it have been studied. At the level of the lesion in animals with prolonged motor latency there was a loss of large myelinated fibres. Remaining large fibres had disproportionately thin myelin sheaths or were demyelinated. Regenerating clusters containing myelinated fibres were present. Evidence of degeneration and regeneration of unmyelinated fibres was present in the more severely affected nerves of this group. Distal to the wrist myelinated fibre density recovered, with regenerating clusters and many axons having disproportionately thin myelin sheaths. Midforearm and upper arm levels were normal. In nerves in which no muscle response to electrical stimulation could be recorded in the palm, a few fibres devoid of myelin remained at the wrist. Immediately proximal to it myelinated fibres were rare, the main feature being Schwann cells containing axons devoid of myelin some of which were degenerating. Degeneration of myelinating fibres within regenerating clusters was seen. At the mid-forearm level large myelinated fibres were reduced and increased numbers of regenerating clusters were seen. Evidence of regeneration of unmyelinated fibres was found. The upper arm was normal.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687242
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  • 24
    Electronic Resource
    Electronic Resource
    In vitro characteristics of a myxopapillary ependymoma of the filum terminale maintained in tissue and organ culture systems (1974)
    Springer
    Acta neuropathologica 27 (1974), S. 185-200 
    Details
    ISSN: 1432-0533
    Keywords: Myxopapillary Ependymoma ; Tissue and Organ Culture ; Electron Microscopy ; Basement Membrane
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Explants of a myxopapillary ependymoma were grown on collagen-coated coverslips and in organ culture systems using gelfoam sponge matrices and Millipore filter platforms. The tumor cultured on collagen-coated coverslips initially exhibited the cytologic features of simple uni- and bipolar glial cells and later developed an epithelial-like pattern. Delicate branching of argyrophilic cell processes was demonstrated in Bodian preparations. In organ cultures, the tumor architecture was well preserved for approximately 4 weeks, and mitotic figures were present. Invasion of the sponge foam matrix was seen. Later cultures demonstrated progressive perivascular sclerosis and hyalinization. By electron microscopy, the tumor cells in organ culture systems retained the major fine structural characteristics of the original neoplasm up to 27 daysin vitro. The most striking feature in the late stages was the extensive increase and reduplication of basement membrane material, which appeared related to the increase of collagen fibrils in the extracellular space.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687629
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  • 25
    Electronic Resource
    Electronic Resource
    Ultrastructural changes in muscle in spinal muscular atrophy —Werdnig-Hoffmann's disease (1974)
    Springer
    Acta neuropathologica 27 (1974), S. 247-256 
    Details
    ISSN: 1432-0533
    Keywords: Werdnig-Hoffmann's Disease ; Electron Microscopy ; Muscle Biopsy ; Myotube-like Cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An ultrastructural study was carried out on muscle biopsies of 7 children with Werdnig-Hoffmann's disease. The muscle fibres were classified into 3 categories: 1. Muscle cells of normal diameter without any distinct or only slight changes. 2. Small muscle cells with a large central nucleus with the appearance of myoblast at a later stage of development. 3. Cells resembling myotubes containing in a common basement membrane two to four cells at different stages of maturation. Myoblast and myotube-like cells seemed to resemble foetal muscle fibres. Such fibres appear to represent an arrest in maturation rather than muscle atrophy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687634
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  • 26
    Electronic Resource
    Electronic Resource
    Etude quantitative de la myélinisation et de la croissance axonale dans le corps calleux et le cordon postérieur de la moëlle chez la souris Jimpy (1974)
    Springer
    Acta neuropathologica 29 (1974), S. 293-309 
    Details
    ISSN: 1432-0533
    Keywords: Jimpy Mouse ; Electron Microscopy ; Mouse Mutant ; Myelination ; Axonal Growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A quantitative study of the myelination and axonal growth in the corpus callosum and posterior columns of the spinal cord in the Jimpy mouse gave the following results: The reduction in the number of myelinated fibers is much more important in regions with late myelination, e.g. corpus callosum and pyramidal tracts than in the previously myelinated fascicles of Goll and Burdach. There is an important delay in the increase in volume of axons particularly within the structures of late myelination. The importance of the lacking axonal growth in relation to myelination is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00685483
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  • 27
    Electronic Resource
    Electronic Resource
    Enzyme histochemical and ultrastructural alterations in the brains of Friesian calves with GM1 gangliosidosis (1974)
    Springer
    Acta neuropathologica 30 (1974), S. 73-84 
    Details
    ISSN: 1432-0533
    Keywords: GM1 Gangliosidosis ; Friesian Calves ; Inborn Metabolic Error ; Histochemistry ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Histoenzymic and ultrastructural alterations in the brains of seven calves with GM1 gangliosidosis are described. A decreased oxidative enzyme activity in neurons was accompanied by an increase in acid phosphatase activity. Membranous cytoplasmic bodies were present in neurons and glia. The periodicity of the membranes was about 5.5 to 6.0 nm. Electron-dense, membrane-bound inclusions were present in perithelial cells. The lesions were compared with those of gangliosidoses in other species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00685324
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  • 28
    Electronic Resource
    Electronic Resource
    Aseptic meningitis due to atheromatous material in the subarachnoid space (1974)
    Springer
    Acta neuropathologica 30 (1974), S. 145-154 
    Details
    ISSN: 1432-0533
    Keywords: Aseptic Meningitis ; Atheromatous Material ; Hypersensitivity ; Electron Microscopy ; Macrophages ; Pia-Arachnoid ; Granuloma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 500 mg of sterile pooled human atheromatous material was injected into the cisterna magna of 6 mongrel dogs. Repeated cisternal punctures were done at various intervals until sacrifice from 1 day to 28 days following injection. CSF was obtained for cell count, sugar, protein and analysis in the Technicon 6/60 which measured 14 additional chemical and enzymatic variables. All 6 animals showed a prompt cerebrospinal fluid (CSF) pleocytosis which largely subsided during the first 2 weeks after injection. Increased CSF protein content developed more slowly, but was more prolonged than the pleocytosis. There was a variable decrease in CSF sugar and increase in CSF lactate dehydrogenase, calcium and inorganic phosphorous. Light and electron microscopic studies showed an intense acute inflammatory reaction with marked phagocytosis of the foregin material, probably by arachnoidal cells and moderate edematous changes in the astrocytic processes at the site of injection. During the first 2 weeks after the injection the inflammatory reaction became chronic and the edematous changes in the medulla subsided.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00685439
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  • 29
    Electronic Resource
    Electronic Resource
    An electron microscope study of reacting astrocytes in gliomas induced by N-ethyl-N-nitrosourea in rats (1974)
    Springer
    Acta neuropathologica 30 (1974), S. 175-181 
    Details
    ISSN: 1432-0533
    Keywords: Reacting Astrocytes ; Phagocytosis ; Experimental Gliomas ; Ethylnitrosourea ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The fine structure of reacting astrocytes in experimental gliomas has been described. These tumours were induced transplacentally by 30 mg of N-ethyl-N-nitrosourea per kg of body weight injected into the tail vein of pregnant BD-IX rats on the 15th day of gestation. In tumour-bearing animals astrocytes undergo striking morphological changes and show increased mitotic activity. Reacting astrocytes around gliomas display large, eccentric, irregular nuclei and the abundant cytoplasm contains an increased number of cell organelles. The most dramatic increase is in glial filaments: these form thick bundles at the periphery of the cells and in the processes which are frequently seen around demyelinated axons. Reacting astrocytes engulf and break down myelin sheaths: their remnants, lamellar inclusion bodies and lipid droplets, are present in the cytoplasm. Extravasated erythrocytes are also surrounded by and digested in reacting astrocytes. Numerous lysosomes could provide the necessary enzymes for the phagocytic activity of these cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00685441
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  • 30
    Electronic Resource
    Electronic Resource
    Congenitally impaired hormone sensitivity of the adipose tissue of spontaneously diabetic mice, KK (1974)
    Springer
    Diabetologia 10 (1974), S. 611-616 
    Details
    ISSN: 1432-0428
    Keywords: Insulin ; epinephrine ; lipolysis ; glucose metabolism ; fat cell ; adipose tissue ; plasma NEFA ; KK ; yellow KK ; C57BL ; diabetes ; genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Adipose tissue of KK mice was less sensitive to insulin in its stimulatory action on glucose oxidation or its inhibitory action on lipolysis, and to epinephrine in its stimulatory action on lipolysis as compared to that of C57BL mice. A lack of appreciable increase in plasma NEFA in response to fasting of the KK mice might be caused by the impaired response of lipolysis to the hormones. — Adipose tissue of KK mice was also less sensitive to insulin-like action of concanavalin A, ouabaine or omission of K+ in the medium on glucose oxidation or lipolysis. Lipolysis in response to theophylline and/or DcAMP was less marked in the tissue of KK mice. The mean diameter of the adipocytes was larger in KK than in C57BL mice. In the experiments using adipocytes with the same diameter, however, the cells of KK mice were less sensitive to the hormones than those of C57BL. — With respect to tissue sensitivity to the hormones, the mean diameter of adipocytes and the response of plasma NEFA to fasting, the F1-hybrid mice of KK and C57BL showed values between those of the parental strains. Yellow hybrid (genetically obese F1-hybrid) mice showed higher sensitivity to insulin in the adipose tissue, more remarkable response of plasma NEFA to fasting as compared with KK mice, although hypertrophy of adipocytes was more pronounced in the yellow hybrid mice. — These findings suggest that insulin insensitivity is associated with epinephrine insensitivity in adipocytes of KK mice; both appear to be subjected to genetic factor(s)per se rather than hypertrophy of the adipocytes. Furthermore, insensitivity to both hormones in the KK mice appears to be caused by a common defect in cellular process other than the hormone receptor systems. These genetically determined abnormalities of adipocytes may result in fat-storage metabolism through hyperinsulinemia; this is very similar to the metabolic profile due to thrifty genotype in human diabetes as proposed by Neel.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01221994
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  • 31
    Electronic Resource
    Electronic Resource
    Effect of ouabain on sodium transport across hormone-stimulated toad bladder and skin (1974)
    Springer
    Pflügers Archiv 347 (1974), S. 275-296 
    Details
    ISSN: 1432-2013
    Keywords: Active Sodium Transport ; Insulin ; Aldosterone ; Vasopressin ; Ouabain
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Exposure of either the isolated urinary bladder or abdominal skin ofBufo marinus to the cardiac glycoside ouabain was regularly followed by reversible decreases of electrical potential difference and short-circuit current. Residual sodium-transporting activity, stable after 1–2h, was a function of the concentration of the glycoside. 2. Ouabain-inhibited preparations still reacted to vasopressin: the hormonal effect was decreased in amplitude only, and this in proportion to decrease in baseline activity; a similar observation was made when aldosterone was responsible for hormonal stimulation. 3. On the other hand, the insulin-induced increment in sodium transport was quite sensitive to ouabain inhibition so that this hormonal effect could be eliminated at moderate concentrations of the glycoside; the same held true when sodium transport was stimulated by addition of glucose to substrate-depleted preparations, especially when they were under the influence of aldosterone. 4. The persistence of residual hormonal effects in the presence of ouabain is interpreted as a type of response due to the stimuli (vasopressin, aldosterone in the absence of exogenous substrate) influencing a step distinct from, and probably proximal to, the ouabain-sensitive sodium “pump” mechanism proper. As for the increased ouabain effect noted on preparations stimulated by insulin or by glucose repletion, it suggests another type of response, possibly characterized by a facilitated interaction between ouabain and specific cell membrane ATP-ase set in operation as a consequence of these treatments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00587169
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  • 32
    Electronic Resource
    Electronic Resource
    Effects of glucose, insulin and glucagon on amylase secretion from incubated mouse pancreas (1974)
    Springer
    Pflügers Archiv 348 (1974), S. 333-342 
    Details
    ISSN: 1432-2013
    Keywords: Mouse Pancreas ; Amylase ; Glucose ; Insulin ; Glucagon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Glucose inhibited amylase release from batch-incubated and perifused pieces of mouse pancreas. Insulin (100μg/ml) reduced the amylase secretion. These effects, however, seemed to be independent of each other, since diazoxide, a potent inhibitor of glucose-induced insulin release, did not abolish the effect of glucose on amylase secretion. Glucagon (10–100 μg/ml) had no effect on the release of amylase from incubated pancreas. Glucagon has previously been shown to inhibit exocrine secretionin vivo. The present results suggest that the inhibitory action of glucagon may be mediated via an increased level of serum glucose and the subsequent release of insulin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00589222
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  • 33
    Electronic Resource
    Electronic Resource
    Intracellular organization of bacteriocin particles in Proteus vulgaris (1974)
    Springer
    Archives of microbiology 98 (1974), S. 271-274 
    Details
    ISSN: 1432-072X
    Keywords: Proteus vulgaris ; Bacteriocin ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The intracellular development of a bacteriocin in a strain of Proteus vulgaris was investigated. Particles which resemble the bacteriocin make their appearance in the cell after 60 min induction with mitomycin C. At this stage they appear as broad bands of tightly-packed phage tail-like structures. With longer periods of induction the bands are disrupted to liberate individual phage tail-like particles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00425288
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  • 34
    Electronic Resource
    Electronic Resource
    Inorganic polyphosphates and enzymes of polyphosphate metabolism in the cellular slime mold Dictyostelium discoideum (1974)
    Springer
    Archives of microbiology 98 (1974), S. 311-329 
    Details
    ISSN: 1432-072X
    Keywords: Dictyostelium discoideum ; Inorganic Polyphosphate ; Electron Microscopy ; Enzymes ; Polyphosphate Metabolism ; Cellular Slime Mold ; Polyphosphatase ; Polyphosphate-ADP-Phosphotransferase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The concentration of inorganic polyphosphates in Dictyostelium discoideum was low in the amoebae. A ca 5-fold increase took place during the early stages of multicellular development and was followed by a decrease during the intermediate stages. Electron micrographs showed the presence of electron dense material in all parts of the differentiating cells. The substance was most frequently observed in various types of vacuoles. Two enzymes of polyphosphate metabolism were identified and studied in cell-free extracts: a polyphosphatase and a polyphosphate-ADP-phosphotransferase. No polyphosphate-glucose-phosphotransferase or polyphosphate-AMP-phosphotransferase activities were observed in the extracts. The specific activity of the polyphosphatase, pH optimum 7.6, was ca 30 nmol Pi·min-1·mg protein-1 at all stages of development. The enzyme activity was not inhibited by 0.01 M orthophosphate. The polyphosphate-ADP-phosphotransferase, pH optimum ca 7.7, was studied in the direction of ATP. The enzyme specific activities were very low, about 0.2 nmol P·min-1·mg protein-1, and rather constant during differentiation. The enzyme activity was inhibited by orthophosphate and by excess ADP. It was concluded that the polyphosphate-ADP-phosphotransferase did not contribute significantly to the formation of ATP during multicellular development, and that polyphosphate did not act as a phosphagen in the differentiating cellular slime mold. It was suggested that polyphosphate served as a phosphate store and as a means of regulating the intracellular orthophosphate concentration during development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00425292
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  • 35
    Electronic Resource
    Electronic Resource
    Mating reaction in Saccharomyces cerevisiae (1974)
    Springer
    Archives of microbiology 97 (1974), S. 27-38 
    Details
    ISSN: 1432-072X
    Keywords: Mass Mating ; Electron Microscopy ; Cell Fusion ; Membrane Structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The process of mating reaction of Saccharomyces cerevisiae was studied by electron microscopy. Prior to the dissolution of the part of the cell walls separating the conjugating pair of cells, the thinning of the electron transparent layer of the cell wall occurs at the part toward which the nuclei are migrating. After the dissolution of the cell walls of the conjugating cells, the cell membranes become associated with each other, then to be broken and rejoined. The first diploid bud emerges from about the middle of the zygote. The morphological changes during the mating reaction are discussed in relation to the biochemical changes so far known.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00403042
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  • 36
    Electronic Resource
    Electronic Resource
    Ultrastructure of a spirochete found in tissues of the brine shrimp,Artemia salina (1974)
    Springer
    Archives of microbiology 99 (1974), S. 281-294 
    Details
    ISSN: 1432-072X
    Keywords: Spirochete ; Artemia ; Brine Shrimp ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract 1. A spirochete which occurs in tissues of the brine shrimp,Artemia salina, was studied by light microscopy and transmission electron microscopy. A total of seven infected shrimps were encountered. 2. Under darkfield illumination, most spirochete cells inArtemia blood were 6–13 μ long and 0.3–0.4 μ wide. Coiling was variable and often irregular. 3. When tissues of the maxillary gland (kidney) and nearby organs were examined by electron microscopy, spirochete cells were found in both extracellular and intracellular locations. These microbes possessed the ultrastructural features typical of members of the Order Spirochaetales: a) a slender protoplasmic cylinder (0.18 μ average diameter), b) axial fibrils (150 A average diameter), and c) an outer envelope or sheath (approximately 75 A thick). 4. Counts made of the number of axial fibrils evident in transverse sections of spirochete cells were consistent with the hypothesis that this spirochete has a 1-2-1 arrangement of axial fibrils. 5. Non-spiral forms were observed in the haemocoel and in the lumen of the maxillary gland.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00696243
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  • 37
    Electronic Resource
    Electronic Resource
    The paradoxical growth hormone reaction after intravenous glucose in the newborn (1974)
    Springer
    European journal of pediatrics 117 (1974), S. 63-72 
    Details
    ISSN: 1432-1076
    Keywords: Growth hormone ; Newborn ; Glucose load ; Insulin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Intravenous glucose tests (0.5 g/kg body weight) were performed in 13 newborn infants during their first 3 days of life. The variations in blood glucose, insulin and GH values were studied. In all patients there was a rise in plasma insulin. The correlation between initial insulin rise and glucose assimilation constant was 0.503 which is almost significant. The glucose load provoked a very variable response in plasma GH concentration, some infants showed a rise, others a fall. If the newborns were grouped according to this reaction it appeared that the GH response could be explained using Wilder's law of initial value. This hypothesis, however, did not stand up to a thorough statistical analysis including a discussion of a less well-known statistical error. In contrast to insulin secretion, GH apparently plays no major role in the short term regulation of the blood sugar in the newborn.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00439024
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  • 38
    Electronic Resource
    Electronic Resource
    Ultrastrukturelle und lichtmikroskopische Befunde bei drei protrahiert tödlich verlaufenen Paraquatvergiftungen (1974)
    Springer
    Lung 150 (1974), S. 185-189 
    Details
    ISSN: 1432-1750
    Keywords: Paraquat Poisoning ; Morphology ; Electron Microscopy ; Light Microscopy ; Letal Course ; Human Lung ; Lung Fibrosis ; Proliferative Alterations ; Degenerative Alterations ; Pathogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Morphological alterations in the lungs of 3 cases of paraquat intoxication with prolonged lethal course (10, 11, and 25 days) are reported. Combined light-and electronmicroscopic studies reveal that 10 and 11 days after the ingestion of paraquat the endothelium of the occassionally congested capillaries is intact. The basal membranes have only scarce alterations. They are sometimes naked because of shadding of both types of pneumocytes with severe alterations, e.g. lipid accumulation in the cytoplasm. In the vast alveolar edema, red blood cells, some round cells, strands of fibrin, and lamellar cell debris are seen. There are also varying amounts of polymorphnuclear leucocytes and alveolar macrophages with many phagolysosomes and cytosegresomes. Fibroblasts with lipid droplets between the extensive RER form varying amounts of collagen fibrils in the alveolar and sometimes in the very edematous interstitial space. Sometimes surrounded by collagenous material, they thus devoured by macrophages. 25 days after paraquat intoxication a severe alveolar fibrosis, focal interstitial fibrosis, and areas with atelectasis are found. Due to artificial respiration and changed ventilation mechanics, there were large areas with hemorrhage and a honeycomb-like structure of the remaining lung parenchyma. The pathogenesis of the degenerative and proliferative lung alterations is briefly discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02179318
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  • 39
    Electronic Resource
    Electronic Resource
    Feinstrukturanalyse der komplexen Geißeln von Rhizobium lupini H 13-3 (1974)
    Springer
    Archives of microbiology 100 (1974), S. 145-162 
    Details
    ISSN: 1432-072X
    Keywords: Complex Flagella ; Fine Structure ; Electron Microscopy ; Optical Diffraction ; Flagellin ; Flagellar Motion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Zellen von Rhizobium lupini H 13-3 besitzen 5–10 peritrich inserierte komplexe Geißeln, deren Feinstruktur durch Hochauflösungs-Elektronenmikroskopie und lichtoptische Diffraktion analysiert wurde. Das Geißelfilament hat einen Durchmesser von 160 Å und besteht aus einem zylindrischen Kern (Durchmesser ca. 110 Å), der fest von drei Bändern einer helikalen Scheide umgeben ist. Die Scheidenbänder sind 49 Å breit, durch 49 Å-Intervalle voneinander getrennt und haben eine Steigung von 31°. Die komplexen Geißelfilamente bestehen aus einem 43 000-Dalton-Protein, das den Kern und die helikale Scheide aufbaut. Beide gehen übergangslos aus dem proximalen Geißelhaken hervor, der einen Durchmesser von 150 Å und eine Länge von 600 bis 800 Å hat. Die Diffraktionsanalyse des Geißelhakens zeigte eine helikale Grundanordnung von globulären Untereinheiten, die ein Oberflächengitter von 5 parallelen Schrauben (Steigung 29° bzw. 33°) bilden, von denen jede fast 11 Untereinheiten pro Helixungang trägt. Die komplexen Geißeln von R. lupini H 13-3 und Pseudomonas rhodos [Schmitt et al.: J. Bact. 117, 844–857 (1974)] sind ein neuer Typ von Bakteriengeißeln. Sie zeigen deutliche Übereinstimmung in der Feinstruktur, der festen Verbindung von helikaler Scheide und Geißelhaken sowie in der Fragilität ihrer Filamente; sie unterscheiden sich deutlich im Molekulargewicht der Flagellinmonomeren (43 000 bzw. 55 000). Zellen von R. lupini H 13-3 führen schnelle, vibrierende Translationsbewegungen aus. Mögliche Mechanismen der Bewegung komplexer Geißeln werden diskutiert.
    Notes: Abstract Cells of Rhizobium lupini H 13-3 possess 5 to 10 peritrichously inserted complex flagella, which were analyzed by high resolution electron microscopy and by optical diffraction. The flagellar filament has a diameter of 160 Å; it consists of a cylindrical core (diameter approximately 110 Å) surrounded by three close-fitting bands of a helical sheath. The helical bands are 49 Å wide, separated by axial intervals, 49 Å wide, and run at an angle of 31°. Complex filaments consist of a 43 000-dalton protein representing the core and the helical sheath. These originate from the proximal hook, which has a diameter of 150 Å and a length of 600 to 800 Å. The diffraction analysis of the hook showed a helical arrangement of globular subunits forming a surface of 5 parallel “small-scale” helices (pitch-angles 29° and 33°, respectively), each carrying almost 11 subunits per period. The complex flagella of R. lupini H 13-3 and Pseudomonas rhodos [Schmitt, et al.: J. Bact. 117, 844–857 (1974)] represent a novel type of bacterial flagella. There is agreement in their fine structures, in the intimate connection of the helical sheath and the core, and in the fragility of their filaments. Thery are clearly distinguished by the molecular weights of their flagellin monomers (43 000 and 55 000, respectively). Cells of R. lupini H 13-3 show fast, vibrating, translational motions. Possible mechanisms of complex flagellar motion are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00446314
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  • 40
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    Electronic Resource
    Citrate lyase from Rhodopseudomonas gelatinosa: Purification, electron microscopy and subunit structure (1974)
    Springer
    Archives of microbiology 100 (1974), S. 307-328 
    Details
    ISSN: 1432-072X
    Keywords: Citrate Lyase ; Subunit Structure ; Electron Microscopy ; Reaction Inactivation ; Rhodopseudomonas gelatinosa ; Phototrophic Bacteria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract 1. Citrate lyase (EC 4.1.3.6) from Rhodopseudomonas gelatinosa has been purified to homogeneity by protamine sulfate fractionation, chromatography on DEAE-Cellulose and gel filtration. The final enzyme preparation had a specific activity of 138 units per mg of protein and was purified 43-fold over the crude extract. Analysis of citrate lyase by sedimentation equilibrium experiments and gel filtration gave molecular weights of 530000 and 560000, respectively. 2. Electron microscopic investigations of negatively stained enzyme molecules and image analysis showed that citrate lyase is composed of six large and six small subunits; they are arranged in two hexagonal rings lying face to face, each containing, in alternating sequence, three large and three small subunits. The enzyme molecule is 160 Å in diameter and about 100 Å thick. 3. Treatment with sodium dodecylsulfate and mercaptoethanol dissociated citrate lyase into three proteins. Protein III (small subunit) had a molecular weight of 30000 and contained the pantothenate; protein II (large subunit) had a molecular weight of 61000; protein I (M r =97000) was probably an aggregate of II and III. 4. Based on the results obtained a model of citrate lyase was constructed. 5. Purified citrate lyase was obtained from R. gelatinosa in a deacetylated and largely oxidized form. The enzyme was activated by reduction with dithiothreitol (3 mM) and subsequent acetylation with acetic anhydride (1.75 mM). 6. The enzyme was subject to reaction inactivation, the extent of which depended on the concentration of Mg2+.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00446325
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  • 41
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    Electronic Resource
    Ultrastructural aspects of localized membrane damage in Spirillum serpens VHL early in its association with Bdellovibrio bacteriovorus 109D (1974)
    Springer
    Archives of microbiology 100 (1974), S. 179-195 
    Details
    ISSN: 1432-072X
    Keywords: Bdellovibrio bacteriovorus ; Spirillum serpens ; Freeze Fracture ; Electron Microscopy ; Ultrastructure ; Membrane Damage ; Organismic Associations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The freeze-fracture technique and electron microscopy have been used to demonstrate that localized damage is inflicted upon the cytoplasmic membrane of Spirillum serpens VHL within 20 to 30 min after the start of its association with Bdellovibrio bacteriovorus 109D. This damage is not observed in uninfected Spirillum cells, nor in infected cells within the first 10 min. This damage takes the form of a “blister” which, when viewed stereoscopically in electron micrographs, is seen to project toward the interior of the Spirillum cell. Shortly after its formation, the blister becomes elaborated into a series of ridges which may assume forms ranging from an elaborate spiral to a series of loops or knots. The formation of a blister is shown to involve both the inner and outer leaves of the membrane bilayer, and evidence is presented to indicate that the blister site corresponds to the site of attachment of the Bdellovibrio cell. The hypothesis is proposed that this ultrastructural damage is the cytological basis for the controlled and localized leakage through the cytoplasmic membrane into the periplasmic space of the Spirillum cell at locations adjacent to the Bdellovibrio cell. It is suggested that this localized membrane damage may be the ultrastructural basis for the high efficiency with which bdellowvibrios are known to incorporate cytoplasmic materials from the other bacteria in whose periplasmic spaces they develop.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00446316
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  • 42
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    Electronic Resource
    Ultrastructural study of pigment cells of human red hair (1974)
    Springer
    Cell & tissue research 150 (1974), S. 167-178 
    Details
    ISSN: 1432-0878
    Keywords: Pigment cell ; Red hair ; Sunburn ; Man ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Pigment cells of human red hair (pheomelanocytes) are never connected to keratinocytes by desmosomes or other defined cell junctions. In the dendritic processes of pheomelanocytes, thin filaments, about 50–80 Å in diameter, and microtubuli can be observed. Early prepheomelanosomes contain loosely arranged filaments. With the onset of pheomelanogenesis dense material is deposited on the filaments. Distinction between late prepheomelanosomes and pheomelanosomes is not clearly possible, because of the disorganized appearance of the content. Furthermore, the content of pheomelanosomes sometimes seems to be disintegrated. By means of the DOPA reaction, tyrosinase activity is shown to be present in: a) prepheomelanosomes, b) large cisternae apposed at one side of dictyosomes, c) small cisternae of the smooth endoplasmic reticulum, and d) coated and uncoated vesicles. The results suggest that red pigment granules are formed in a manner similar to that of melanin granules. It is further assumed that an inadequate stability of pheomelanoprotein accounts for the inability of red-haired people to develop effective protection against ultraviolet light.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00222168
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  • 43
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    Electronic Resource
    Alteration of metabolic and hormonal responses to exercise by physical training (1974)
    Springer
    European journal of applied physiology 33 (1974), S. 215-226 
    Details
    ISSN: 1439-6327
    Keywords: Exercise ; Training ; FFA ; Ketones ; Insulin ; Growth Hormone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Eight young men underwent a programme of training by running for 30 min at moderate speed three times a week for 4 weeks. Metabolic and hormonal changes in blood were studied during and after a run of 60 min at comparable speeds before and at the end of the training programme. Increases in lactate, pyruvate and plasma FFA during exercise were less after training. Increases in glucose were greater. There was a smaller increase in the post-exercise concentration of blood ketone-bodies after training. Plasma levels of insulin and human growth hormone (HGH) were lower after training. The fall in insulin and the rise in HGH during exercise were also smaller. There is a dissociation of the normal relationship between blood glucose and insulin during exercise. Insulin appears to be more important in the control of fat metabolism, in which its role may be altered by physical training. The changes observed in the longitudinal study of training imply that differences observed in cross-sectional studies of athletes and untrained subjects are not the result of an innate difference but do depend upon metabolic changes related to athletic training.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00421149
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  • 44
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    Electronic Resource
    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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  • 45
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    Electronic Resource
    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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  • 46
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    Electronic Resource
    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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  • 47
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    Electronic Resource
    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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  • 48
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    Electronic Resource
    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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  • 49
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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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  • 50
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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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    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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    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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  • 54
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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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  • 55
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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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  • 56
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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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  • 57
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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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  • 58
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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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  • 59
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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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    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070242
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  • 63
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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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    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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  • 65
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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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    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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    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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    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070326
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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.
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    URL: http://dx.doi.org/10.1002/cber.19741070334
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  • 70
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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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  • 71
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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.
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    URL: http://dx.doi.org/10.1002/cber.19741070403
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  • 72
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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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  • 73
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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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  • 74
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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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  • 75
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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.
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    URL: http://dx.doi.org/10.1002/cber.19741070419
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  • 76
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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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  • 77
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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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  • 78
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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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  • 79
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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 
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    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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  • 80
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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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  • 81
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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.
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    URL: http://dx.doi.org/10.1002/cber.19741070602
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  • 82
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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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  • 83
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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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    Derivate des Guanidins mit N—S- und N—P-Bindungen (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1536-1544 
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    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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    Konformationsanalyse, III. exo-Anomerer Effekt und Circulardichroismus von Glycopyranosylaziden (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1568-1578 
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    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.
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    URL: http://dx.doi.org/10.1002/cber.19741070517
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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.
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    URL: http://dx.doi.org/10.1002/cber.19741070522
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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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    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.
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    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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    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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    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070626
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  • 98
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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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  • 99
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    Electronic Resource
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070631
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  • 100
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    Electronic Resource
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070705
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