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  • 1980-1984
  • 1975-1979  (1,341)
  • 1978  (1,341)
  • Inorganic Chemistry  (765)
  • Physics  (504)
  • Nuclear reactions
  • Rat
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Material
Years
  • 1980-1984
  • 1975-1979  (1,341)
Year
Keywords
  • 1
    Electronic Resource
    Electronic Resource
    Some observations on the efferent innervation of rat soleus muscle spindles (1978)
    Springer
    Experimental brain research 31 (1978), S. 433-443 
    Details
    ISSN: 1432-1106
    Keywords: Rat ; Soleus ; Fusimotor innervation ; Skeletofusimotor innervation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In the small segmental tail muscles of the rat beta fibres provide exclusively the dynamic fusimotor control, while gamma fibres provide exclusively the static fusimor control. The present experiments were made to investigate the fusimotor innervation of spindles in a large muscle of the rat, the soleus, and thus to determine the occurrence and significance of beta innervation in this muscle. Our results have revealed no case of beta innervation in the rat soleus. As a consequence of our experimental method, however, we would not claim that beta innervation does not exist in the soleus, only that it must play an insignificant role relative to that seen in the tail segmental muscles. Investigations of the fusimotor innervation of eight spindles were sufficiently complete to warrant detailed illustration. The number of gamma fibres ranged from two to four. In every case the slowest conducting gamma fibre was dynamic. However, the conduction velocity spectra for the static and dynamic gamma fibres to rat soleus overlap to such an extent that it is impossible to use conduction velocity as the sole guide to functional gamma fibre classification. The pooled results from the eight spindles fully investigated provide a ratio of static to dynamic gamma fibres of approximately 1:1. Other evidence discussed in the paper suggests that in the muscle nerve the ratio is considerably higher. These differences are reconciled if the dynamic gamma fibres branch more profusely and innervate more spindles than do the static gamma fibres.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237300
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  • 2
    Electronic Resource
    Electronic Resource
    Hippocampal place units in the freely moving rat: Why they fire where they fire (1978)
    Springer
    Experimental brain research 31 (1978), S. 573-590 
    Details
    ISSN: 1432-1106
    Keywords: Hippocampus ; Place units ; Unit recording ; Sensory cues ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Place units in the dorsal hippocampus of the freely-moving rat signal the animal's position in an environment (place field). In the present experiments, thirty four place units were recorded in two different environments: one, a small platform where the rat had received neither training nor reward; the other, an elevated T-maze inside a set of black curtains where the rat had been trained on a place discrimination. The places within the curtained enclosure were specified by four cues (a light, a card, a fan, and a buzzer) in addition to the food. Other cues were eliminated by rotating the maze and the four controlled cues relative to the external world from trial-to-trial. Some units had place fields in both environments while others only had a place field in one. No relationship could be seen between the place fields of units with fields in both environments. All twelve units tested extensively in the controlled enclosure had place fields related to the controlled cues. Probe experiments in which only some of the controlled cues were available showed that some of these units were being excited by one or two cues while others were influenced in a more complex way. The fields of these latter units were maintained by any two of the 4 cues and were due to inhibitory influences which suppressed the unit firing over the rest of the maze.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00239813
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  • 3
    Electronic Resource
    Electronic Resource
    Hypothalamically induced intraspecific aggressive behaviour in the rat (1978)
    Springer
    Experimental brain research 32 (1978), S. 365-375 
    Details
    ISSN: 1432-1106
    Keywords: Intraspecific aggression ; Lateral hypothalamus ; Electrical stimulation ; Specificity ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of electrical stimulation of the lateral hypothalamus (LH) of rats on intraspecific aggressive behaviour were studied. In order to investigate the specificity of the stimulation effects, each experimental animal was stimulated in a number of different social situations. Stimulation of the LH in the presence of a subordinate male increased the amount of time spent on aggressive behaviour patterns and locomotion. In the presence of a dominant male, however, the stimulated animal never initiated a fight, whereas in the presence of an estrous female attack occurred in some rare occasions and sexual behaviour disappeared almost entirely. Stimulation of some sites also elicited mouse killing behaviour. Many of the electrodes that elicited intraspecific aggressive behaviour also supported intracranial self-stimulation. It is concluded that 1. electrical stimulation of this area of the LH predominantly potentiates intraspecific aggressive behaviour, 2. that this behaviour becomes overt depends on the external situation, including the behaviour of the opponent.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238708
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  • 4
    Electronic Resource
    Electronic Resource
    Membrane-associated adenosine triphosphatase in normal and injured hypoglossal nuclei (1978)
    Springer
    Experimental brain research 33 (1978), S. 213-225 
    Details
    ISSN: 1432-1106
    Keywords: Rat ; Hypoglossal nucleus ; Axotomy ; ATP-ase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The hypoglossal nuclei of adult male albino rats, either normal, or from 1 to 70 days after left hypoglossal nerve transection, were studied cytochemically with a lead method for sodium- and potassium-activated membrane ATP-ase, using light and electron microscopy. Reaction product was measured at the light microscopical level by microdensitometry, and significance determined statistically. Light microscopy revealed a brown reaction product in the neuropil, but none in cell bodies. Blood vessel walls were more strongly coloured. Reaction product was undiminished by ouabain pre-incubation, or by incubation without sodium or potassium, or by incubation with calcium instead of magnesium. Reaction product was diminished by absence of magnesium if calcium was also absent, and abolished if sections were boiled before incubation, or if substrate was absent. Axotomy caused a statistically significant increase in neuropil reaction product in injured nuclei, maximal at 35 days postoperatively, and subsequently decreasing to normal at 70 days. Electron microscopy showed a predominantly surface membrane reaction product, with occasional positive intracellular cisternae. Basal lamina and intra-endothelial vacuoles were also positive. Axotomy resulted in the arrival and disappearance of microglia (2 to 35 days), followed by astrocyte hypertrophy (35 days), and increase in thickness and homogeneity of surface membrane reaction product. The results suggest the presence of one or more calcium- or magnesium-dependent membrane ATP-ases. The peak of the increase after axotomy is probably partly attributable to hypertrophic astrocytes, and partly to the surfaces of neuronal processes. Increase of membrane movements might explain such enzyme activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238061
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  • 5
    Electronic Resource
    Electronic Resource
    Some effects of chlordiazepoxide and d-amphetamine on response force during punished responding in rats (1978)
    Springer
    Psychopharmacology 56 (1978), S. 211-215 
    Details
    ISSN: 1432-2072
    Keywords: Chlordiazepoxide ; d-Amphetamine ; Response force ; Punishment ; Stereotyped behavior ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Rats were reinforced with water on a continuous reinforcement schedule and were also punished with electric shock for every fifth response applied to a silent, isometric, force-sensing manipulandum. Oral doses of chlordiazepoxide (3.0, 9.0, 27.0 mg/kg) increased both conventional rate and force of punished responding. In contrast, d-amphetamine (0.8, 1.6, 3.2 mg/kg, by gavage) further decreased conventional rate and force of response, but this latter drug increased the rate of recorded responses that were lower than the 15-g force criterion for response consequences. The results for chlordiazepoxide are viewed in terms of its anxiolytic properties, while the d-amphetamine data appear to support a theory of amphetamine effects based on the concept of stereotyped behaviors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00431852
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  • 6
    Electronic Resource
    Electronic Resource
    Accelerated development of tolerance during repeated cycles of ethanol exposure (1978)
    Springer
    Psychopharmacology 60 (1978), S. 59-65 
    Details
    ISSN: 1432-2072
    Keywords: Ethanol ; Tolerance ; Behavioral augmentation ; Physical dependence ; Carry-over ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Adult male rats were subjected to 1–4 cycles of daily gastric intubation with ethanol (6 g/kg) for 16 days, separated by 17-day alcohol-free periods. Tolerance produced by this treatment (designated ‘physiological tolerance’) was measured by change in effect of a 2.2 g/kg i.p. dose of ethanol on the moving-belt test. It occurred in each cycle, disappeared completely in the drug-free periods, and developed more rapidly in the second and later cycles than in the first. Tolerance produced by the ‘behavioral augmentation’ technique (daily test practice under the influence of ethanol) also developed more rapidly on a second than on a first cycle. The progression from within-session to between-session tolerance was still evident, but accelerated. With 25-day alcohol cycles, separated by a one-month drug-free period, the ‘carry-over’ effect (i.e., more rapid acquisition of tolerance in the second cycle) applied equally, regardless of whether or not tolerance was produced by the same technique in both cycles, or by a crossover in either direction between the two techniques.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00429180
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  • 7
    Electronic Resource
    Electronic Resource
    Influence of polyphloretin phosphate on the central effects of prostaglandin E2 and F2α in rats (1978)
    Springer
    Psychopharmacology 59 (1978), S. 273-277 
    Details
    ISSN: 1432-2072
    Keywords: Polyphloretin phosphate ; Prostaglandins ; Behaviour ; Temperature ; Bram biogenic amines ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The possibility that polyphloretin phosphate (PPP) antagonizes the central effects elicited by prostaglandin (PG) E2 and F2α was investigated. PPP was administered i.c.v. to male Wistar rats (10 or 25 μg) 10 or 30 min before i.c.v. injection of PGE2 or PGF2α (1 or 10 μg). The duration of several components of behavior, the degree of irritability, and the rectal temperature of rats were measured; the levels of noradrenaline, dopamine, 5-hydroxytryptamine, and 5-hydroxyindoleacetic acid were measured spectrophotofluorometrically in discrete brain areas. PPP antagonized temperature and behavioral changes induced in rats by PGF2α, but not those induced by PGE2. The magnitude of antagonism depended on the dose of PPP and on the time of the pretreatment before PGF2α administration. Changes in the level of biogenic amines in discrete brain areas evoked by PGs were not affected by PPP. We found that PPP antagonizes the central effects of PGF2α but not those of PGE2, and that changes of biogenic amines in discrete brain areas elicited by PGs are not specific.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00426634
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  • 8
    Electronic Resource
    Electronic Resource
    Myopathy associated with chronic alcohol drinking (1978)
    Springer
    Virchows Archiv 378 (1978), S. 45-53 
    Details
    ISSN: 1432-2307
    Keywords: Alcohol ; Myopathy ; Histochemistry ; Electrophysiology ; Human ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Muscles of the lower legs of rats given 25% ethanol in water ad libitum for up to 9.5 months were studied using histological, histochemical and electrophysiological techniques. Ethyl alcohol was substituted for about 20% of the total calorific input of the animals. The observations were compared with the structure of the gastrocnemius muscle of five alcoholics with clinical neuropathy. Fibrillation potentials and angulated atrophic fibers were observed in the muscles of animals on alcohol for 9.5 months. No fiber type grouping was present. There was also phagocytosis of the muscle fibers and changes in their internal structure, as reflected by the distribution of NADH-diaphorase. The observed muscle changes in the alcoholics and those in the experimental animals on alcohol differed mainly quantitatively, the only exception being the presence of fiber type grouping in the biopsies from the alcoholics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00427185
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  • 9
    Electronic Resource
    Electronic Resource
    Sauerstoffverbrauch und Gewichtsentwicklung chronisch urämischer Ratten (1978)
    Springer
    Research in experimental medicine 173 (1978), S. 239-244 
    Details
    ISSN: 1433-8580
    Keywords: Experimental chronic uremia ; Rat ; Oxygen consumption ; Body weight ; Experimentelle chronische Urämie ; Ratte ; Sauerstoffverbrauch ; Körpergewicht
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die verminderte Gewichtszunahme bei experimenteller chronischer Urämie führte zu der Bestimmung des Sauerstoffverbrauches chronisch urämischer Ratten und eines normalen Vergleichskollektivs. Die Messung des Sauerstoffverbrauches wird als Hinweis auf den Energiebedarf des Gesamtstoffwechsels gewertet. Drei Gruppen von Versuchstieren wurden untersucht: urämische Ratten (CU) von geringerem Gewicht (403,66 ± 9,9 g) als deren gesunde Vergleichstiere (NA) (498,31 ± 26,13) und jüngere Normaltiere (NJ), welche ein annähernd ähnliches Körpergewicht wie die chronisch Niereninsuffizienten aufwiesen (376,0 ± 8,8). Signifikante Unterschiede des Sauerstoffverbrauches, bezogen auf das Körpergewicht, wurden zwischen den Gruppen NJ (0,927 ± 0,042 ml O2/mn/100 g Ratte) und beiden Gruppen CU und NA (0,788 ± 0,036 und 0,788 ± 0,028 jeweils) gefunden. Eine proportionale Verminderung der energetisch aktiven Körpermasse mag die Ursache der Sauerstoff-Meßergebnisse bei chronischer experimenteller Urämie sein.
    Notes: Summary Impaired weight gain, a common feature in experimental chronic uremia, led to compare oxygen consumption values of chronic uremic rats and their controls. Oxygen consumption measurement may allow an approach to the evaluation of total energy requirement. Three groups of animals were considered: uremic rats (CU) of less weight (402.66 ± 9.9 g) than their control group (NA) (498.31 ± 26.13) and younger normal animals (NJ), showing a similar weight (376.0 ± 8.8) to that of the uremics. Significant differences in oxygen consumption values/body weight were found between group NJ (0.927 ± 0.042 ml O2/mn/100 g rat) and both groups CU and NA (0.788 ± 0.036 and 0.788 ± 0.028 respectively). Proportional decrease of energetically active body mass in chronic uremic animals may be the reason of the findings.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01851495
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  • 10
    Electronic Resource
    Electronic Resource
    Complement system in sodium taurocholate pancreatitis in the rat (1978)
    Springer
    Research in experimental medicine 174 (1978), S. 57-65 
    Details
    ISSN: 1433-8580
    Keywords: Complement system ; Sodium taurocholate ; Acute experimental pancreatitis ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The role of the complement system was studied in Na-taurocholate pancreatitis in rats. Complement activity (CH 50) was determined at various times in the course of pancreatitis. Immediately after induction of acute pancreatitis, serum complement activity declined and massive C 3 deposits could be detected in the vicinity of acinar necroses and necrobioses. After a phase of recovery three to six hours postoperatively a second complement consumption occurred. Lethality rate increased as serum complement activity fell below 50% of preoperative values. The degree of C 3 deposition increased up to six hours. Decline of serum complement activity and deposition within the pancreas seemed to be correlated with histologically demonstrable tissue lesion. The first decline of complement activity in serum is thought to be caused by liberation of complement activating substances within the pancreas due to the detergent action of Na-taurocholate itself. The second decline, however, may be due to the liberation of complement activating and/or destroying enzymes into the blood stream.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01851939
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  • 11
    Electronic Resource
    Electronic Resource
    Technique of continuous collection of parotid saliva in the rat (1978)
    Springer
    Research in experimental medicine 172 (1978), S. 247-253 
    Details
    ISSN: 1433-8580
    Keywords: Rat ; Parotid saliva
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A method is described, which is suitable to collect continuously and quantitatively saliva from both parotid glands in rats under in vivo conditions and which allows to investigate salivary electrolyte composition in relation to flow rate during several hours. This might be of expanding scientific interest in disturbances of transepithelial electrolyte transport in various pathophysiological situations (for instance different forms of experimental hypertension, endstage renal failure and so on).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01855835
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  • 12
    Electronic Resource
    Electronic Resource
    Normal and 6-aminonicotinamide impaired development of capillarization in occipital cortex of rat (1978)
    Springer
    Anatomy and embryology 154 (1978), S. 27-37 
    Details
    ISSN: 1432-0568
    Keywords: Capillarization ; Cortex ; Rat ; 6-Aminonicotinamide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary During different embryonic and postnatal stages, 6-aminonicotinamide (6-AN) was administered to Wistar albino rats. The capillarization of the occipital cortex has been examined morphometrically. A 6-AN-vulnerable stage of prenatal development was found, which lasted to the 19th prenatal day and which only partly corresponds to the so-called ‘critical stage’ of capillary sprouting (Kapillarsprossung). Capillary sprouting was not impaired by 6-AN during postnatal stages. Impairment of capillarization by 6-AN might be the result of glial lesion. The importance of glia for capillarization is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00317952
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  • 13
    Electronic Resource
    Electronic Resource
    Scanning electron microscopic studies of ileal epithelial cells in suckling rats (1978)
    Springer
    Anatomy and embryology 153 (1978), S. 1-8 
    Details
    ISSN: 1432-0568
    Keywords: Ileal epithelial cell ; Suckling period ; Rat ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ileal epithelial cells containing the tubulo-vacuolar systems and supranuclear vacuoles in suckling rats were investigated with scanning electron microscopy, using specimens treated with osmium-thiocarbohydrazide-osmium staining methods, and critical point drying and cracking. The cracked surface of the apical cytoplasm is seen as irregular and small hollows and pores of the anastomosing and branching tubulo-vacuolar system. The cracked surface of the supranuclear vacuoles shows the ellipsoidal structures. Numerous pores of various size and irregular shape are present on the apical inner surface of the supranuclear vacuole. These pores are clearly the openings from the tubulo-vacuolar system to the supranuclear vacuole. Some small pores are visible on the inner lateral surface of the supranuclear vacuole, especially near the nucleus. They are probably the pathways of the absorbed materials from the supranuclear vacuole into the lateral cytoplasm. Usually, the inclusions of the supranuclear vacuole reveal the globes or coarse and sponge-like networks.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00569845
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  • 14
    Electronic Resource
    Electronic Resource
    Pre- and postnatal development of catecholamine-containing and cholinesterase-positive nerves of the rat cornea and iris (1978)
    Springer
    Anatomy and embryology 154 (1978), S. 253-265 
    Details
    ISSN: 1432-0568
    Keywords: Rat ; Iris ; Cornea ; Catecholamine fluorescence ; Cholinesterase ; Histochemistry ; Ontogenesis ; Catecholamines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Glyoxylic acid-induced fluorescence technique and a copper thiocholine method were used to investigate the ontogenesis of the catecholamine-containing and cholinesterase-positive nerves of the rat iris and cornea. First fluorescent nerve fibres appeared in the iris on the 18th gestation day and in the cornea on the 19th day. A rapid increase in the density of the adrenergic nerve fibres of the iris continued to the age of three weeks, while the number of such fibres were small in the cornea. Acetylcholinesterase-positive fibres appeared both in the cornea and in the iris on the 19th gestation day. Their density increased more rapidly in the iris, especially in the sphincter muscle, than in the cornea. Non-specific cholinesterase activity was localized in the Schwann cells and the reaction was more intense during development than in the nerves of the cornea of adult rats.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00345656
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  • 15
    Electronic Resource
    Electronic Resource
    Developmental organization of raphe serotonin neuron groups in the rat (1978)
    Springer
    Anatomy and embryology 154 (1978), S. 241-251 
    Details
    ISSN: 1432-0568
    Keywords: Nervous system ; Serotonin ; Raphe nuclei ; Development ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The pre- and early postnatal development of serotonin neurons in the rat brainstem was studied using the fluorescence histochemical method. The technique utilized does not require drug pretreatment to visualize an intense serotonin fluorophore localized in neuronal perikarya, dendrites, and axons. All the serotonin neuron groups develop as bilateral nuclei which extend from the midbrain through the medulla. Six of the nine groups undergo a midline fusion from embryonic day 18 (E 18) through postnatal day 6 (P 6) in a rostrocaudal gradient. Cells of the nucleus raphe dorsalis fuse first (by P1), whereas the serotonin neurons located in nucleus raphe pallidus do not fuse until P 6. This gradient is comparable to the one described for the first observable fluorescence in the serotonin neurons groups. After final cell division, the serotonin neurons undergo a primary migration from the ventricular zone along the midline, where they are situated during embryogenesis, and a secondary migration extending into postnatal life which concludes with fusion in the midline. The bilateral origins of the serotonin cell groups are maintained in the adult. This is expressed by the apparent ipsilateral projections of some of the raphe neurons determined recently in our laboratory utilizing autoradiographic and horseradish peroxidase techniques.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00345655
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  • 16
    Electronic Resource
    Electronic Resource
    Direct characterization ofΒ-adrenoceptors in membranes of immature red blood cells from rats (1978)
    Springer
    Annals of hematology 37 (1978), S. 295-306 
    Details
    ISSN: 1432-0584
    Keywords: Β-adrenerge Rezeptoren ; (3H) (−) Dihydroalprenolol ; Erythrozyten ; Ratte ; Β-Adrenoceptors ; (3H) (−) Dihydroalprenolol ; Erythrocytes ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary By means of the radioactive antagonist ligand (3H) (−) dihydroalprenolol (DHAP) specific binding sites were identified in membrane preparations from red blood cells from rats. These specific sites were characterized asΒ-adrenoceptors because of the following reasons: Specific binding of DHAP (in contrast to unspecific binding) was dependent on temparature and time of incubation. Furthermore, specific binding of DHAP showed saturability, temperature-dependent reversibility and high affinity (KD-value of DHAP = 6.51 nM). Specific binding of DHAP was competitively inhibited byΒ-adrenergic antagonists (pindolol 〉 alprenolol ≧ propranolol 〉 practolol) and agonists (isoprenaline 〉 adrenaline). The (−) enantiomers of pindolol and isoprenaline showed pronounced higher affinities for the receptor sites than the respective (+) enantiomers. The receptor density in the membrane preparations (pmoles/mg protein) was strongly dependent on the degree of reticulocytosis: The Bmax-values increased more than 4 to 5 fold without alteration of the respective KD-values when reticulocyte counts were enhanced from 3 to 80 % treatment of the animals with increasing doses of acetyl phenylhydrazine.
    Notes: Zusammenfassung Mittels des radioaktiv markierten Antagonist-Liganden (3H) (−) Dihydroalprenolol (DHAP) wurden spezifische Bindungsstellen in Membran-PrÄparationen von Erythrozyten der Ratte identifiziert, die aus folgenden Gründen alsΒ-adrenerge Rezeptoren angesprochen werden können: Im Gegensatz zur unspezifischen Bindung von DHAP war die spezifische Bindung abhÄngig von der Inkubationszeit und der Temperatur. Sie folgte einer SÄttigungskinetik, war — in AbhÄngigkeit von der Temperatur — reversibel und wies eine hohe AffinitÄt auf (KD für DHAP = 6,51 nM). Die rezeptorspezifische Bindung von DHAP wurde durchΒ-Rezeptorenblocker (Pindolol 〉 Alprenolol ≧ Propranolol 〉 Practolol) oderΒ-Sympathomimetika (Isoprenalin 〉 Adrenalin) kompetitiv gehemmt. Die (−) Enantiomeren von Pindolol und Isoprenalin hatten eine wesentlich höhere AffinitÄt als die antsprechenden (+) Enantiomeren. Die Dichte Β-adrenerger Rezeptoren (pmole/mg Eiwei\) nahm mit steigendem Retikulozytosegrad zu: Sie stieg auf das 4-bis 5fache an, wenn die Retikulozytenwerte durch Vorbehandlung der Tiere mit Azetylphenylhydrazin von 3 auf 80 % gesteigert wurden.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01007864
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  • 17
    Electronic Resource
    Electronic Resource
    Der Sauerstoffverbrauch des spontanen und künstlich induzierten Hautcyclus zu verschiedenen Tageszeiten (1978)
    Springer
    Archives of dermatological research 262 (1978), S. 167-172 
    Details
    ISSN: 1432-069X
    Keywords: Rat ; Oxygen uptake ; Induced skincycle ; Spontaneous skincycle ; Diurnal rhythm ; Ratte ; Sauerstoffverbrauch ; Induzierter Hautcyclus ; Spontaner Hautcyclus ; Tagesschwankung
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung In der vom Panniculus carnosus gereinigten “glatten” Rattenhaut wurde der Sauerstoffverbrauch des spontanen und induzierten Hautcyclus zu verschiedenen Tageszeiten ermittelt. Das Niveau des Sauerstoffverbrauches korrelierte mit den Tag-Nacht-Zeiten. Der Sauerstoffverbrauch zeigte während des Hautcyclus Schwankungen. Ferner fanden sich Anhaltspunkte, daß der frühanagene Wert des Sauerstoffverbrauches von der Cyclusphase mit beeinflußt wird, während welcher der neue Cyclus künstlich induziert wird. Weiter wurde festgestellt, daß eine gewisse Abnahme des Sauerstoffverbrauches die ruhenden Haarfollikel zur spontanen Proliferation anregt. Während des Katagen schien der Maximalwert des Sauerstoffverbrauches mit speziellen morphofunktionellen perifollikulären Veränderungen in Beziehung zu stehen. Die Übertragung dieser Befunde auf die Pathophysiologie menschlicher Haarwachstumsstörungen wird erwogen.
    Notes: Summary In the “clean” rat skin purified from the panniculus carnosus the oxygen consumption of the spontaneous and artificially induced skincycle was measured at different times of day. The level of oxygen consumption correlated to diurnal and nocturnal periods. During the skincycle the oxygen consumption showed fluctuations. There were indications that the value of oxygen consumption of the early anagen is influenced by that phase of the cycle at which the new cycle is artificially induced. Furthermore, it was found that a certain decrease of oxygen consumption stimulates the quiescent hair follicles to spontaneous proliferation. During the katagen the peak value of the oxygen consumption seemed to be correlated with specially morphofunctional perifollicular changes. The application of these findings to the pathophysiology of human hair growth disturbances is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00455386
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    Electronic Resource
    Electronic Resource
    Morphological changes in CNS of rats treated with perhexiline maleate (Pexid) (1978)
    Springer
    Acta neuropathologica 42 (1978), S. 159-164 
    Details
    ISSN: 1432-0533
    Keywords: Perhexiline maleate ; Pexid ; Abnormal inclusion ; Rat ; CNS
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The basic cellular lesion in CNS of suckling rats treated with Pexid was studied by light and electron microscopy. The most pronounced abnormality, the formation of various intracytoplasmic inclusions, was found in neurons, astrocytes, oligodendrocytes, ependymal cells, endothelial cells and fibroblasts. These abnormal inclusions were generally membrane-bound, although clearly non-membrane-bound inclusions were occasionally found. The several internal patterns of the inclusions were (1) lamellar, both concentric and parallel, (2) reticular and (3) crystalloid. These alterations were completely resersed following withdrawal of the drug. The structural characteristics of the abnormal inclusions in Pexid-treated animals were similar to those found with certain hypocholesterolemic, neuroleptic, anorectic, and antimalarial drugs. This suggests that the inclusions occurring within the cells of animals treated with any of these drugs may develop in a similar manner, and that the formation of such inclusions is likely to be a form of cellular reaction common to certain metabolic disturbances.
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    URL: http://dx.doi.org/10.1007/BF00690352
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  • 19
    Electronic Resource
    Electronic Resource
    Ultrastructural studies on blood-brain barrier dysfunction after cerebral air embolism in the rat (1978)
    Springer
    Acta neuropathologica 44 (1978), S. 53-56 
    Details
    ISSN: 1432-0533
    Keywords: Blood-brain barrier ; Air embolism ; Horseradish peroxidase ; Cerebral cortex ; Electron microscopy ; Carotid artery ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Male albino rats were anaesthetized with diazepam, injected with horseradish peroxidase and Evans blue-labeled albumin and given an embolus of 0.01 ml air in the right common carotid artery after ligation of the external carotid branch. The pial arteries of the right cerebral hemisphere were stained blue, particularly the middle cerebral artery and its main arterial branchlets. Ultrastructurally, some endothelial cells in the right middle cerebral artery, small arteries and arterioles showed a diffuse distribution of horseradish peroxidase in their cytoplasm, although these vessels only occasionally showed peroxidase in their basement membranes. Other endothelial cells in these arterial branchlets showed few if any signs of a diffuse distribution of peroxidase but displayed several pinocytotic vesicles and occasionally trans-endothelial channels filled with peroxidase, sometimes with a slight leakage of peroxidase into adjacent basement membranes and neuropil. Scattered pinocytotic vesicles were observed in capillaries and venules, but there was usually no extravasation of peroxidase around these vessels.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00691639
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  • 20
    Electronic Resource
    Electronic Resource
    Cadmium induced endothelial cell alterations in the fetal brain from prenatal exposure (1978)
    Springer
    Acta neuropathologica 44 (1978), S. 147-149 
    Details
    ISSN: 1432-0533
    Keywords: Cadmium ; Endothelial cell ; Capillary ; Fetal brain ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Pregnant rats received a single administration of 0.5, 1.0, or 2.0 mg/kg of cadmium on day 18 or 20 or gestation Maternal animals were killed on day 21 and samples of the caudate nucleus from fetal brains were examined using the transmission electron microscope. A 2.0 mg/kg dose of cadmium administered to maternal rats on day 20 of gestation caused the formation of vacuoles in the endothelial cells of capilaries in the fetal brain. Significant endothelial cell vacuolization was not observed in the brain of fetuses from other treatment groups. The vacuoles occurred singly, were spherical in shape, were located adjacent to the intercellular junctions and caused focal distortion of the endothelial cell. Vacuoles were the only ultrastructural alteration observed in the caudate nucleus of fetal brains.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00691482
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  • 21
    Electronic Resource
    Electronic Resource
    The influence of protein-calorie malnutrition on the development of internodal segments. A study on peripheral nerve and spinal roots in rats (1978)
    Springer
    Acta neuropathologica 41 (1978), S. 103-108 
    Details
    ISSN: 1432-0533
    Keywords: Protein-calorie malnutrition ; Rat ; Spinal root ; Sciatic nerve ; Internodal length
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The current investigation comprised normal young rats as well as rats submitted to a 50% food reduction or severe protein restriction. Isolated nerve fibres from lumbar spinal roots and sciatic nerves were investigated with reference to the relation between length and diameter of internodes as well as variation of internodal length along single nerve fibres. The present results do not support the view that protein-calorie malnutrition should cause neuropathy. Internodal segments were, on an average, shorter in relation to their thickness in young rats submitted to severe protein restriction or a 50% food reduction. The deviation was most marked in low-protein animals and particularly among coarser internodal segments. An inhibition of longitudinal growth was considered to be the main factor behind the difference between malnourished and normal rats.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00689760
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  • 22
    Electronic Resource
    Electronic Resource
    Tumor specific fluorescent and complement-dependent cytotoxic antibodies in the serum of rats with chemically induced brain gliomas (1978)
    Springer
    Acta neuropathologica 43 (1978), S. 111-117 
    Details
    ISSN: 1432-0533
    Keywords: Experimental brain gliomas ; Chemically induced ; Rat ; Cell cultures ; Humoral antibodies ; Immunofluorescence staining ; Microcytotoxicity assay
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Brain tumors were induced in Sprague-Dawley and Long-Evans rats by administration of N-methyl-N-nitrosourea in the drinking water. Of these tumors, a grade 2 mixed glioma, a grade 2 to 3 astrocytoma and a grade 1 to 2 oligodendroglioma were established in vitro, maintained in culture and designated 75SD-G-376, 75SD-G-420 and 77LE-G-180, respectively. Of these mass cultures, two were successfully cloned and are currently available as 75SD-G-376C and 75SD-420C cell lines. Clonal lines produce S-100 protein and grow as tumors when isografted in young rats. Using the cultured cells as target cells, specific antibodies were searched for in the sera of the rats with the primary tumors by means of an indirect fluorescent antibody staining method and a complement-dependent antibody-mediated microcytotoxicity assay. Fluorescent and cytotoxic antibodies were demonstrated in the sera of the mixed glioma- and astrocytoma-bearing animals. However, a variable proportion of cells of the 75SD-G-376 and 75SD-G-420 lines showed no reaction with the corresponding sera. Furthermore, cytotoxic anfibodies had a lytic effect on the autologous glioma cells only in the presence of rabbit complement.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00685005
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  • 23
    Electronic Resource
    Electronic Resource
    Schwann cells and peripheral nervous system myelin in the rat retina (1978)
    Springer
    Acta neuropathologica 44 (1978), S. 245-247 
    Details
    ISSN: 1432-0533
    Keywords: Schwann cells ; PNS myelin ; Retina ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Within the retinal nerve fiber layer of a 6-week-old Sprague-Dawley rat, scattered aggregates of PNS myelinated axons have been found and described. We believe this is likely to represent a normal but rare phenomenon in the rat.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00691075
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  • 24
    Electronic Resource
    Electronic Resource
    Scanning electron microscopical study on the fluorosis of enamel in rats (1978)
    Springer
    Calcified tissue international 25 (1978), S. 75-83 
    Details
    ISSN: 1432-0827
    Keywords: Rat ; Fluorosis ; Enamel ; Scanning electron microscopy ; Low temperature incineration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Sixteen 58-day-old male rats of Wistar strain, with a mean body weight of 179 g, were divided into two equal groups. Each group of eight animals was maintained for 70 days on drinking water, ad lib., containing no fluorine (control group) and 100 ppm of fluorine (experimental group). All specimens examined were obtained from the incisal portions of the incisors. The following types of enamel specimens were prepared for scanning electron microscopy: (1) acid-etched specimens; (2) acid-etched specimens followed by low temperature microincineration; and (3) fractured specimens. The enamel formed during high fluoride exposure showed marked hypocalcification, that is, the crystallite density in the prism core and interprismatic region was lower than that of control animals. The organic substances appeared to increase in these regions. These changes were prominent in the outer and middle enamel layers. Such changes following fluoride administration appear to indicate an inhibition of enamel maturation, that is, an inhibition of the mineral deposition and/or an inhibition of organic matrix withdrawal.
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    URL: http://dx.doi.org/10.1007/BF02010754
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  • 25
    Electronic Resource
    Electronic Resource
    The effect of some neuroleptics on the interaction of cortically and nigrally evoked potentials in the rat striatum (1978)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 303 (1978), S. 165-170 
    Details
    ISSN: 1432-1912
    Keywords: Striatum ; Evoked potentials ; Neuroleptics ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The interaction of cortico- and nigrofugal inputs to the striatum of the rat was investigated using the technique of evoked potentials. Repetitive, unilateral stimulation of the substantia nigra inhibited potentials which were evoked from the ipsilateral rostral cortex and recorded from the ipsilateral striatum. The inhibition was antagonized by low doses of various intraperitoneally administered neuroleptics such as: pimozide (0.1–0.2 mg/kg), haloperidol (0.1–0.5 mg/kg), chlorpromazine (0.5–2.0 mg/kg) and thioridazine azine (0.5–4.0 mg/kg). These findings are discussed in view of the existing controversy regarding the mode of action of dopamine in the striatum.
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    URL: http://dx.doi.org/10.1007/BF00508063
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  • 26
    Electronic Resource
    Electronic Resource
    Blood O2 content, cardiac output, and flow to organs at several levels of oxygenation in rats with a left-shifted blood oxygen dissociation curve (1978)
    Springer
    Pflügers Archiv 376 (1978), S. 201-207 
    Details
    ISSN: 1432-2013
    Keywords: Oxygen dissociation curve ; Oxygen transport ; Cardiac output ; Coronary blood flow ; Blood flow to organs ; Hypoxia ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A major displacement of the blood O2 dissociation curve (ODC) was achieved in rats by chronic administration of sodium cyanate (NaOCN). Control animals with a normal position of the ODC received NaCl instead. Arterial and mixed-venous O2 content ( $${\text{C}}_{{\text{O}}_{\text{2}} }$$ ) and O2 consumption were measured during breathing room air, 14.9, 8.0, or 5.6% O2 in N2. Cardiac output was obtained by the Fick principle.86RbCl was administered i.v., the rats were killed and the activity of86Rb in heart, spleen, stomach and intestines, liver, kidney, skeletal muscle, and skin was measured. According to Sapirstein (1956, 1958) the fractional uptake of86Rb in these organs corresponds to the fractions of cardiac output supplying these organs, and from the fractional uptake and cardiac output the nutritional blood flow may be calculated. Arterial and mixed-venous $${\text{C}}_{{\text{O}}_{\text{2}} }$$ was larger in the NaOCN than in the NaCl rats at all levels of oxygenation. At normoxia and 14.9% O2 the venous $${\text{C}}_{{\text{O}}_{\text{2}} }$$ was enlarged more than the arterial one, and so the arterio-venous O2 difference [ $$\left( {{\text{a}} - {\text{v}}} \right)_{{\text{O}}_{\text{2}} }$$ ] as an index of the O2 extraction in the body was smaller in the rats with a left-shifted ODC. However, at more severe hypoxia (8.0 and 5.6% O2) the arterial $${\text{C}}_{{\text{O}}_{\text{2}} }$$ in the NaOCN rats was enlarged more than the mixed-venous one, resulting in a larger $$\left( {{\text{a}} - {\text{v}}} \right)_{{\text{O}}_{\text{2}} }$$ (and therefore O2 extraction) when compared with the NaCl animals. Cardiac output was larger in the NaOCN than in the NaCl rats at 14.9 and 5.6% O2, when expressed per kg body weight. At 14.9% O2 the augmented cardiac output compensated for the lower O2 extraction when compared with the NaCl animals. At 5.6% O2 the NaOCN rats had both a larger ( $$\left( {{\text{a}} - {\text{v}}} \right)_{{\text{O}}_{\text{2}} }$$ ) and cardiac output than the NaCl animals. In the NaCl rats the decreased O2 extraction was not compensated for by an augmented cardiac output and therefore their O2 consumption was not only lower than that of the NaOCN rats but decreased even below the normoxic value of the NaCl rats. Coronary blood flow was increased in both NaOCN and NaCl animals at deep hypoxia to about the same extent, but due to a much lower arterial $${\text{C}}_{{\text{O}}_{\text{2}} }$$ of the NaCl animals, their O2 supply to the heart was lower than that of the NaOCN rats. The nutritional blood flow to spleen, kidney, liver, stomach and intestines, and skin in ml/min · g was lower in the rats with a normal position of the ODC than in those with a left-shifted ODC. This, together with the low arterial $${\text{C}}_{{\text{O}}_{\text{2}} }$$ of the NaCl rats, suggests a serious compromising of the O2 supply to these organs. Results of this study support the conclusion of our theoretical studies (Turek et al., 1973; Turek and Kreuzer, 1976) that a shift of the ODC to the left might be disadvantageous for the O2 transport to tissues at mild hypoxia, but advantageous at severe hypoxia.
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    URL: http://dx.doi.org/10.1007/BF00584951
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    Electronic Resource
    Electronic Resource
    Arterial blood gases, muscle fiber diameter and intercapillary distance in cardiac hypertrophy of rats with an old myocardial infarction (1978)
    Springer
    Pflügers Archiv 376 (1978), S. 209-215 
    Details
    ISSN: 1432-2013
    Keywords: Blood gases ; Cardiac hypertrophy ; Intercapillary distance ; Myocardial infarction ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In rats with a myocardial infarction due to ligation of the left coronary artery a marked right ventricular hypertrophy developed after 41/2 weeks. At this time no difference against control animals was observed in arterial $$P_{{\text{O}}_2 }$$ , $$P_{{\text{CO}}_2 }$$ , pH, ideal alveolar $$P_{{\text{O}}_2 }$$ , and alveolar-arterial O2 pressure difference, as measured in unanesthetized animals at normoxia. In histological sections of the heart stained by PAS reaction capillaries and muscle fibers were counted, and the mean intercapillary distance and muscle fiber diameter were estimated. In the right ventricle of the rats with myocardial infarction both increased when compared with control animals or with sham-operated rats. Fibercapillary ratio was the same in all three groups. Similar results were obtained in the remaining undamaged tissue of the left ventricle of rats with a myocardial infarction when compared with the left ventricle of control or sham-operated rats. Findings concerning intercapillary distance suggest that also in the myocardium which remains intact during the development of the infarction and later hypertrophies, tissue oxygen transport might be impaired, particularly during a stress situation. Results in the right ventricle of rats with myocardial infarction show an opposite trend against rats exposed chronically to simulated high altitude, where in the hypertrophied right ventricle a shorter intercapillary distance occurs and therefore an improvement of tissue oxygen transport might be expected.
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    URL: http://dx.doi.org/10.1007/BF00584952
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  • 28
    Electronic Resource
    Electronic Resource
    Concentrative amino acid uptake at the serosal side of colon mucosa (1978)
    Springer
    Pflügers Archiv 376 (1978), S. 245-249 
    Details
    ISSN: 1432-2013
    Keywords: Colon ; Amino acid uptake ; Basolateral membrane ; Active transport ; Sheep ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Uptake of the nonmetabolizable model amino acid 2-aminoisobutyric acid (=AIB) through the basolateral membrane into epithelial cells was studied in sheep colon stripped of serosa and muscle layers. Only the antiluminal surface of the mucosa was exposed to the incubation medium. Thus AIB entry into epithelial cells could only occur through the basolateral membrane. AIB was taken up by a saturable process against a high concentration gradient. AIB uptake was inhibited by other neutral amino acids but not by sugars. In a low Na+ medium AIB uptake was impaired, indicating that active transport of amino acids through the basolateral membrane of colon epithelial cells is Na+-dependent. In the rat a saturable concentrative uptake of AIB through the basolateral membrane of colon epithelial cells has also been demonstrated. Concentrative uptake of amino acids through the basolateral membranes is probably important for the supply of colon epithelium with amino acids.
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    URL: http://dx.doi.org/10.1007/BF00584958
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  • 29
    Electronic Resource
    Electronic Resource
    Rat intestinal brush border enzymes release by deoxycholate in vivo (1978)
    Springer
    Pflügers Archiv 373 (1978), S. 133-138 
    Details
    ISSN: 1432-2013
    Keywords: Deoxycholate ; Intestinal perfusion ; Rat ; Enzymatic release ; Localization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The release of proteins, sucrase (SA), maltase (MA), leucine aminopeptidase (LA) and alkaline phosphatase (AP) activity from rat jejunum by sodium deoxycholate (DOC) was studied by an in vivo perfusion technique. In our experimental conditions, a 2 mmol/l DOC perfusion for 30 min induced a marked and reversible release of proteins and hydrolases. When specific activities were considered, each enzyme showed a distinct release pattern. Significantly, the SA release was largely increased, the AP release was decreased and there was no correlation between the releases of SA and AP. Furthermore, the various enzymes recovered into the lumen were solubilized at different extents. SA was chiefly present in a soluble and AP in a particular form. The microscopical appearances showed a slight exfoliation of the epithelial cells from the villous tips but no specific changes when compared to the control group. The results are discussed in terms of enzymic localization in the brush border membrane; SA would be located very superficially in the surface membrane and AP buried in the membrane and less accessible than the other enzymes.
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    URL: http://dx.doi.org/10.1007/BF00584851
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  • 30
    Electronic Resource
    Electronic Resource
    Dissociation between antidiuretic response and renal medullary cyclic AMP levels in the rat (1978)
    Springer
    Pflügers Archiv 374 (1978), S. 229-234 
    Details
    ISSN: 1432-2013
    Keywords: Cyclic AMP ; ADH ; Vasopressin ; Isoproterenol ; 3-isobutyl-1-methylxanthin ; Rat ; Water diuresis ; Antidiuresis ; Dehydration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In vivo experiments were performed in male Wistar rats to elucidate the probable relation between renal concentrating ability and medullary cyclic AMP content as influenced by changes of hydration and by administration of antidiuretic hormone (ADH). Cyclic AMP levels were 37% lower in water diuretic than in control animals (P〈0.01), but were not significantly changed during prolonged antidiuresis induced by dehydration or ADH administration. Nor could any change of cyclic AMP levels be demonstrated between 2 and 20 min after ADH injection. Significant increases of medullary cyclic AMP content occurred following stress, anesthesia, and administration of isoproterenol and 3-isobutyl-1-methylxanthin. The results suggest that the level of cyclic AMP in the renal medulla may not be an important determinant of the antidiuretic response produced by ADH in rats.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00585599
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  • 31
    Electronic Resource
    Electronic Resource
    Blood volume and body haematocrit of rats native to a simulated altitude of 3500 m (1978)
    Springer
    Pflügers Archiv 374 (1978), S. 285-288 
    Details
    ISSN: 1432-2013
    Keywords: High altitude ; Blood volume ; Red cell volume ; Plasma volume ; Body haematocrit ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Circulating blood volume (BV) as the sum of circulating red cell volume (RCV) and plasma volume (PV) was estimated in rats native to a simulated altitude of 3500 m (“natives”), in rats born at sea level and later in life transferred to the simulated high altitude (“newcomers”), and in control sea-level rats. RCV per kg body weight (b.w.) was significantly larger in both “newcomers” and “natives” than in controls. PV per kg b.w. was in the “newcomers” insignificantly and in the “natives” significantly smaller than in the controls. BV per kg b.w. in both high altitude groups tended to be larger than in controls but the difference was not significant. Arterial haematocrit (Ahct) in the “newcomers” was significantly higher than in the controls, and in the “natives” significantly higher than in both other groups. Body haematocrit (the ratio of RCV and BV in per cent) was smaller than Ahct in all groups; this was more pronounced in the “newcomers” than in the controls and even more so in the “natives”. Apparently the haematocrit in the minute vessels of the organs of animals exposed to chronic hypoxic hypoxia increases much less than might be expected from changes of the Ahct. An attempt was made to evaluate the possible error of the more commonly used method of estimating BV, when only RCV, or only PV, is measured, and BV and its complementary fraction are calculated from arterial or venous haematocrit. When, in our results, BV was calculated from RCV and Ahct, the absolute values and also the differences between groups were somewhat underestimated. When BV was calculated from PV and Ahct, the BV itself, and particularly the differences between groups, were overestimated quite considerably. It is suggested that the only safe way to estimate BV is to measure RCV and PV separately.
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    URL: http://dx.doi.org/10.1007/BF00585606
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  • 32
    Electronic Resource
    Electronic Resource
    Influence of glomerular filtration rate on renal PAH secretion rate in the rat kidney (1978)
    Springer
    Pflügers Archiv 375 (1978), S. 131-139 
    Details
    ISSN: 1432-2013
    Keywords: PAH clearance ; PAH extraction ; Glomerular filtration rate ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract PAH secretion (TPAH) was studied in rats at spontaneously occurring glomerular filtration rate (GFR). At saturated transport, TPAH was found to be correlated to GFR. This relationship was also observed at unsaturated transport where TPAH depends upon the PAH concentration in arterial plasma. However, no significant correlation between TPAH and renal PAH load or renal plasma flow rate was found when the effects of GFR were removed by partial correlation analysis. A dependency of TPAH on GFR explains the correlations found between filtration fraction (FF) and renal PAH extraction (EPAH) or renal tubular PAH extraction fraction (EPAH-FFPAH). Thus, even at low PAH concentration in a. plasma, renal PAH extraction may only be assumed to be constant if the filtration fraction is constant.
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    URL: http://dx.doi.org/10.1007/BF00584235
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  • 33
    Electronic Resource
    Electronic Resource
    Blood gases at several levels of oxygenation in rats with a left-shifted blood oxygen dissociation curve (1978)
    Springer
    Pflügers Archiv 376 (1978), S. 7-13 
    Details
    ISSN: 1432-2013
    Keywords: Oxygen dissociation curve ; Oxygen transport ; Blood gases ; Hypoxia ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Theoretical deductions have shown that a shift of the blood O2 dissociation curve (ODC) to the right might improve O2 transport to tissues at normoxia and at mild hypoxia whereas at severe hypoxia the organism should be better off with an ODC shifted to the left (Turek et al., 1973b; Turek and Kreuzer, 1976). The present study was performed in order to ascertain this ambiguous effect of an ODC shift depending on the degree of hypoxia in intact animals. A major displacement of the ODC to the left was achieved in rats by chronic administration of sodium cyanate (NaOCN). Control animals received sodium chloride (NaCl) instead. Arterial and mixed-venous $$P_{{\text{O}}_{\text{2}} }$$ , $$P_{{\text{CO}}_{\text{2}} }$$ , and pH were measured at normoxia and during breathing 14.9, 8.0, or 5.6% O2 in N2 in both groups. From $$P_{{\text{O}}_{\text{2}} }$$ , pH, ODC and arterial hematocrit, arterial and mixed-venous O2 contents were estimated and $$({\text{a}} - {\text{v)}}_{{\text{O}}_{\text{2}} }$$ as an index of blood O2 extraction was obtained. At normoxia and during breathing 14.9% O2 the NaOCN rats had a lower mixed-venous $$P_{{\text{O}}_{\text{2}} }$$ than the NaCl rats without any difference in pH. Arterio-venous O2 difference did not differ at normoxia but was lower in NaOCN rats at 14.9% O2. However, at 8.0 and 5.6% O2 the NaOCN rats had a higher mixed-venous $$P_{{\text{O}}_{\text{2}} }$$ , an increased $$({\text{a}} - {\text{v)}}_{{\text{O}}_{\text{2}} }$$ , and a higher pH (arterial and mixed-venous). At 5.6% O2 the NaCl rats developed a severe acidosis concomitant with pronounced hypocapnia. These findings confirm that rats with a left-shifted ODC have an impaired O2 transport to tissues at normoxia and mild hypoxia but a more efficient O2 transport at severe hypoxia as compared with rats with an unshifted ODC, in agreement with our previous theoretical studies.
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    URL: http://dx.doi.org/10.1007/BF00585241
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    Electronic Resource
    Effect of acute and chronic cadmium treatment on hepatic drug metabolism in male rats (1978)
    Springer
    Archives of toxicology 40 (1978), S. 269-277 
    Details
    ISSN: 1432-0738
    Keywords: Cadmium ; Drug Metabolism ; Metallothionein ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effect of acute and chronic cadmium administration on hepatic drug metabolism was investigated in the male rat. 3 days after the acute administration of cadmium by either the intraperitoneal (0.84 mg Cd/kg) or the oral (〉 80 mg Cd/kg) route, there was a significant potentiation in duration of hexobarbital hypnosis and inhibition of hepatic microsomal metabolism of hexobarbital and aniline. Administration of cadmium in the drinking water at levels of 100 or 200 ppm Cd for periods of 2–12 weeks or at levels of 5 or 20 ppm Cd for 50 weeks did not produce alterations in either drug response or hepatic drug metabolism. Significant levels of metallothionein, a cadmium binding protein, found in the liver of the rats receiving cadmium chronically may offer an explanation for the observed differences in drug metabolism between the acute and chronic administration of cadmium. In additional studies, pretreatment of the rats with subthreshold doses of cadmium (0.21 or 0.42 mg Cd/kg) intraperitoneally produced a tolerance to the alterations in drug metabolism induced by the previous cadmium dose (0.84 mg Cd/kg, i.p.). However, chronic cadmium treatment (5 or 20 ppm Cd for 50 weeks) did not impart any such tolerance to subsequently administered Cd (0.84 mg/kg) by the intraperitoneal route. The hepatic levels of metallothionein induced by the chronic cadmium treatment were only 30–60% of those induced by the subthreshold cadmium and thus may not have bound enough of the large challenge cadmium dose to produce the tolerance phenomenon.
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    URL: http://dx.doi.org/10.1007/BF00310332
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  • 35
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    Electronic Resource
    Studies of rat alkaline phosphatase (1978)
    Springer
    Archives of toxicology 39 (1978), S. 267-287 
    Details
    ISSN: 1432-0738
    Keywords: Rat ; Plasma ; Alkaline phosphatase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This report describes the application of a test system which applies different substrates, inhibitors and acrylamide electrophoresis to the study of the alkaline phosphatase activity of rats. The system, which was specifically devised to characterise the alkaline phosphatase activity of small quantities of plasma from rats in toxicological studies, was also used to examine the plasma from rats under several physiological conditions, e.g. time of day, age, diet, etc. These physiological factors can influence the measurement of plasma alkaline phosphatase activity and should be taken into account when designing toxicological studies. Different experimental regimes were used to produce increases in liver, bone and intestinal alkaline phosphatase isoenzymes in the plasma of rats and these were reflected in the characterisations by the system. Although much remains unknown, a few concepts of rat plasma alkaline phosphatase activity emerged under our conditions. There is a ‘tidal’ intestinal component which arises from feeding and is approximately 60% of the total activity of the fed rat. In the fasted rat this ‘tidal’ component has largely disappeared and the ‘core’ activity which remains is composed of approximately equal proportions of bone isoenzyme and another as yet ill-defined component. The liver isoenzyme which appears in the plasma of the cholestatic rat appears to be either a very minor component or absent from the plasma of our normal CFE derived rat.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00296387
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  • 36
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    Accelerated elimination of thallium in the rat due to subchronic treatment with furosemide (1978)
    Springer
    Archives of toxicology 40 (1978), S. 7-16 
    Details
    ISSN: 1432-0738
    Keywords: Thallium ; Furosemide ; Acetazolamide ; Renal elimination ; Oral absorption ; 204Tl ; Kidney ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Im Rahmen einer Untersuchung über das Schicksal von Thallium im Organismus und über den Einfluß von Diuretika auf die Eliminationsgeschwindigkeit dieses Giftes wurde Tl2SO4 (48.9 μmol = 10 mg/kg) an wachen Ratten oral verabreicht. Die Blutspiegel von Tl+ wurden anschließend als Funktion der Zeit ermittelt, sie konnten mit einer klassischen Bateman-Funktion nicht richtig beschrieben werden. Etwa l Std nach oraler Verabreichung war die Blutkonzentration maximal. Die Behandlung mit Furosemid (30 mg/kg) beschleunigte die Entfernung von Thallium aus dem Organismus auf signifikante Weise. Etwa 35% der zugeführten Menge Thallium wurde während einer Woche nach der Injektion dieses Diuretikums mit dem Urin ausgeschieden. Auch die Ausscheidung von Natriumionen und Wasser war signifikant erhöht, die von Kaliumionen blieb jedoch fast unverändert. Thallium selbst verursachte eine schwache diuretische Wirkung. Nach fortgesetzter Behandlung mit Furosemid (bis 2 Wochen) blieb die Eliminationsgeschwindigkeit von Thallium, Wasser und Natrium beschleunigt, während die Ausscheidung von Kaliumionen im Vergleich zu Kontrolltieren etwas herabgesetzt war. Ethacrynsäure verursachte nach wiederholter Gabe in diuretisch wirksamen Dosen eine retroperitoneale Fibrose. Dieses wirksame Diuretikum konnte daher nicht in die Untersuchung einbezogen werden. Acetazolamid (30 mg/kg) erhöhte ebenfalls die Ausscheidung von Thallium, vor allem innerhalb der anfänglichen 24 Std. Die Wirkung war weniger intensiv als die von Furosemid, sie war außerdem bald erschöpft. Die Ergebnisse legen den Schluß nahe, Furosemid in hohen Dosen sei eine wirksame Maßnahme zur Beschleunigung der Thalliumentfernung aus dem Organismus, zumindest im vorliegenden Tiermodell. Acetazolamid ist zu diesem Zwecke wahrscheinlich nicht geeignet.
    Notes: Abstract In connection with a programme of investigations concerning the disposition of thallium in the rat and the influence of diuretic agents on the rate of elimination of thallium from the body, Tl2SO4 (48.9 μmol = 10 mg/kg) was given by mouth to conscious rats. Blood levels were studied as a function of time. They could not be described adequately by means of a classical Bateman function. The maximum blood level was achieved approximately 1 h following oral ingestion. Treatment with furosemide for 11 days (30 mg/kg twice daily) significantly accelerated the removal of thallium from the body with the urine. Approximately 35% of the administered thallium was excreted within one week following the injection of this diuretic agent. The excretion of sodium and water was also considerably enhanced, that of potassium hardly changed. Thallium itself displayed weak diuretic activity. Upon prolonged treatment (1–2 weeks) with furosemide the elimination of thallium, water and Na+ was still accelerated, although that of potassium proved diminished with respect to controls. Ethacrynic acid when administered repeatedly in appropriate doses caused retroperitoneal fibrosis. Therefore, this potent diuretic agent was not included in the investigations. Acetazolamide (30 mg/kg) also enhanced the excretion of thallium, especially within the initial 24 h of treatment. The effect was less pronounced than that of furosemide and rapidly exhausted. The results suggest that furosemide in a high dose is effective in accelerating thallium elimination from the body in the present animal model. Acetazolamide is probably not suitable for this purpose.
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    URL: http://dx.doi.org/10.1007/BF00353275
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  • 37
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    Electronic Resource
    Distention ulcer as a model for testing of drugs for ulcerogenic side effects (1978)
    Springer
    Archives of toxicology 41 (1978), S. 99-105 
    Details
    ISSN: 1432-0738
    Keywords: Rat ; Method ; Gastric ulceration ; Distention of stomach ; Stress ; Anti-inflammatory drugs ; Ulcerogenic side effect
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Das sog. „distention“-Ulkus wurde an Albinoratten untersucht und als neue Möglichkeit für die Feststellung ulzerogener Nebenwirkungen von Substanzen beschrieben. Die Dehnung des Magens in sich war nicht ausreichend um ulzerogene Läsionen auszulösen, denn die Dehnung des Magens mit physiologischer Kochsalzlösung führte nicht zur Ulzeration. Die Säure ist ein entscheidender Faktor in der Bildung des „distention“-Ulkus. Große Volumina von 0,1 N Salzsäure riefen innerhalb von 1 Std massive Ulzeration hervor. Kleine Mengen von dieser Säurelösung verursachten keine Ulzeration im Magen. Entzündungshemmer, die in noch von ulzerogenen Nebenwirkungen freien therapeutischen Dosen verabreicht wurden, erhöhten die Empfindlichkeit der gastralen Mukosa dem aggressiven Faktor, der Säure, gegenüber. Bei den mit bekanntlich ulzerogen wirkenden Dosen von Entzündungshemmern vorbehandelten Ratten wurde eine schnellere Bildung von Ulzera durch die Dehnung des Magens mit Säure beobachtet. Auch die Stressvorbehandlung beschleunigte und verstärkte die Bildung der durch Dehnung hervorgerufenen ulzerogenen Veränderungen im Magen.
    Notes: Abstract A modification of the distention ulcer was studied in albino rats and a new possibility of testing ulcerogenic side effects of drugs was described. The distention alone was not sufficient to produce lesions. The severity of ulcer lesions was highly dependent on the volume of the acid solution. Large volumes of 0.1 N HCl evoked severe ulcers within 1 h. Small amounts of weak acid solution did not cause any ulceration. Anti-inflammatory drugs administered in therapeutic doses, which did not yet produce any ulcers in animals, increased the sensitivity of the gastric mucosa against the aggresive factor, the acid. In animals pretreated by anti-inflammatory drugs in toxic doses an earlier development of ulceration was observed by distention with acid. Stress also accelerated and aggravated the formation of distention ulcers.
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    URL: http://dx.doi.org/10.1007/BF00351774
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  • 38
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    Electronic Resource
    Studies of rat alkaline phosphatase (1978)
    Springer
    Archives of toxicology 39 (1978), S. 249-266 
    Details
    ISSN: 1432-0738
    Keywords: Rat ; Alkaline phosphatase ; Plasma ; Organs ; Toxicity testing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A manual system of various estimations of rat plasma alkaline phosphatase activity has been devised for small volumes of plasma which uses different inhibitors, compares the utilisation of two substrates and includes acrylamide gel electrophoresis. The different inhibitors etc. allow a degree of discrimination between alkaline phosphatase extracts of rat organs. The properties of isoenzymes, e.g. intestinal alkaline phosphatase, differ depending upon the environment in which they are studied. In conjunction, if necessary, with the methods described for the estimation of liver and intestinal alkaline phosphatase activity, it is hoped to use the system to discriminate between the isoenzymes present in the plasma alkaline phosphatase of rats in toxicological studies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00296386
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  • 39
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    Electronic Resource
    In vivo DNA repair after N-methyl-N-nitrosourea administration to rats of different ages (1978)
    Springer
    Journal of cancer research and clinical oncology 91 (1978), S. 157-164 
    Details
    ISSN: 1432-1335
    Keywords: MNU ; DNA Repair ; Rat ; Age
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary DNA repair time-course was studied after injury by N-methyl-N-nitrosourea (MNU) in rat liver cells of animals of different ages and in fetuses using hydroxyurea (HU) as inhibitor of scheduled DNA synthesis. DNA repair was a rapid phenomenon, more so in young adults than in newborns, and was not detectable in fetuses. A correlation seems to exist among organ sensitivity to carcinogen, age of animal and DNA repair.
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    URL: http://dx.doi.org/10.1007/BF00284022
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  • 40
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    Electronic Resource
    Perhexiline induces generalized lipidosis in rats (1978)
    Springer
    Journal of molecular medicine 56 (1978), S. 309-310 
    Details
    ISSN: 1432-1440
    Keywords: Perhexilin-Maleat ; generalisierte Lipidose ; Ratte ; Perhexiline maleate ; Generalized lipidosis ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Administration of perhexiline (Pexide®) to rats causes generalized occurrence of lamellated and crystalloid cytoplasmic inclusions which resemble those described in patients with perhexiline-induced polyneuropathy. It is concluded that perhexiline being an amphiphilic cationic compound is a potent inducer of generalized lipidosis.
    Notes: Zusammenfassung Perhexilin (Pexid®) verursacht bei der Ratte das generalisierte Auftreten von lamellären und kristalloiden zytoplasmatischen Einschlußkörpern, die denjenigen gleichen, die bei Patienten mit Perhexilin-induzierter Polyneuropathie beschrieben worden sind. Aus den vorgelegten Befunden wird geschlossen, daß Perhexilin, eine amphiphile kationische Verbindung, ein starker Induktor einer generalisierten Lipidose ist.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01489178
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  • 41
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    Electronic Resource
    On the presence and distribution of α-adrenoceptors in the heart of various mammalian species (1978)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 302 (1978), S. 239-254 
    Details
    ISSN: 1432-1912
    Keywords: Myocardial α-adrenoceptors ; Rat ; Guinea pig ; Cat ; Hypothyroidism ; Single adrenoceptor type
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The presence and distribution of myocardial α-adrenoceptors in different parts of the heart of various mammalian species was investigated. For this reason experiments were performed in isolated cardiac preparations of rats, guinea pigs and cats. In order to obtain more information about the nature of the cardiac α-adrenoceptors additional experiments were undertaken at different temperatures. These studies were aimed to show whether or not a conversion of β-to α-adrenoceptors or vice versa takes place. Moreover, we analyzed the influence of hypothyroidism on the sensitivity of α- and β-adrenoceptors of preparations from rats fed with propylthiouracil. Finally, we tried to find out whether stimulation of these α-adrenoceptors leads to the formation of the cyclic nucleotides cAMP and cGMP. The following results were obtained: 1. In right ventricular strips of rats, guinea pigs and cats phenylephrine stimulated α-adrenoceptors. After blockade of β-adrenoceptors the respective pD2-values of phenylephrine were 5.32, 5.99 and 5.33. The doseresponse curves obtained in the presence of α-adrenolytic drugs were shifted to the right without depression of the maximum. In the rat, in addition, the pA2-values for the α-adrenolytic drugs yohimbine (5.79) and phentolamine (7.85) were determined. They were at least 0.5 log units higher than those found in the rat for other α-adrenoceptors (Van Rossum, 1965) thus supporting the view that the population of cardiac α-adrenoceptors is different from that of other organs. In left ventricular strips of guinea pigs the pD2-value for the α-mimetic effect of phenylephrine was of the same order of magnitude as that obtained in the right ventricle. 2. In the papillary muscle of the right ventricle of guinea pigs and cats phenylephrine stimulated α-adrenoceptors. 3. In the left atrium of the rat, phenylephrine stimulated myocardial α-adrenoceptors (pD2: 5.58). Also in this preparation the pA2-values for yohimbine (6.36) and phentolamine (8.21) were different from those found for other α-adrenoceptors in the rat (Van Rossum, 1965). Likewise in strips from the left atrium of the cat myocardial α-adrenoceptors are present. 4. In spontaneously beating right atria of the rat a clear-cut positive chronotropic effect mediated by stimulation of α-adrenoceptors could not be demonstrated although in 6 out of 15 preparations a small positive chronotropic effect became evident. No positive chronotropic effect at all was obtained by stimulation of α-adrenoceptors in the cat right atrium. 5. In ventricular strips as well as in left atria from hypothyroid rats the pD2-value for the α-effect of phenylephrine was increased, in the atrium more than in the ventricle, while the pA2-values for yohimbine and phentolamine were not significantly different from the controls. Under these conditions a distinct positive chronotropic effect mediated by stimulation of α-receptors was found in the spontaneously beating rat atrium. 6. After stimulation of α-adrenoceptors in atria and ventricular strips of normal and propylthiouraciltreated rats, as well as in strips of guinea-pig ventricles or cat atria no elevation of cAMP and cGMP was observed. 7. The concept of a single adrenoceptor convertible from α- to β-type or vice versa was not supported by our experiments. These were carried out at different temperatures on left atria and on ventricular strips of rat hearts using the irreversible α-adrenoceptor blocking agent phenoxybenzamine. 8. The present experiments provide evidence for the existence of α-adrenoceptors in the myocardium of various mammalian species. Their stimulation produces positive inotropic effects without increases in heart rate.
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    URL: http://dx.doi.org/10.1007/BF00508293
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  • 42
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    Diurnal variations in the motor activity of the rat: Effects of inhibitors of the catecholamine synthesis (1978)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 303 (1978), S. 251-256 
    Details
    ISSN: 1432-1912
    Keywords: Diurnal rhythm ; Motor activity ; Rat ; H 44/68 ; FLA 63 ; Animex
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of the inhibitor of the tyrosine-hydroxylase H 44/68 and the inhibitor of the dopamine-β-hydroxylase FLA 63 on the diurnal variations of the motor activity was studied in male Wistar rats, which were kept under standardized conditions of light and darkness (L:D=12:12h). The motor activity was continuously registered in groups of 5 rats using a two-channel Animex motimeter. During light FLA 63 (40 mg/kg, s.c.) greatly increased motor activity on acute application and during darkness the physiological elevation in motor activity was further but slightly increased. H 44/68 (200 mg/kg, i.p.) also increased motor activity during light, but in contrast to FLA 63 greatly reduced motor activity during darkness. The results indicate that though dopamine and noradrenaline are involved in the regulation of behavioural components, one or the other catecholamine may play a predominant role at different times of the day. Thus, it seems worthwhile to study the effects of drugs separately during light and during darkness.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00498051
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  • 43
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    Electronic Resource
    Diurnal rhythm in the central dopamine turnover in the rat (1978)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 303 (1978), S. 257-261 
    Details
    ISSN: 1432-1912
    Keywords: Diurnal rhythm ; Central noradrenaline and dopamine turnover ; H 44/68 ; FLA 63 ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Under controlled conditions of environmental light and darkness of 12:12 h the turnover of dopamine and noradrenaline in brain of male Wistar rats was studied at different times of the day. The turnover was calculated from the decline of the amine concentrations either after inhibition of the tyrosine-hydroxylase with H 44/68 (200 mg/kg, i.p.) or after inhibition of the dopamine-β-hydroxylase with FLA 63 (40 mg/kg s.c.). Whereas the noradrenaline turnover showed only slight but not significant variations within 24 h, the turnover of the central dopamine exhibited significant variations with increased turnover rates in the second half of the light and first half of the dark period. Thus, diurnal variations have to be taken into account when studying the effects of drugs on the turnover of biogenic amines in the central nervous system.
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    URL: http://dx.doi.org/10.1007/BF00498052
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  • 44
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    Electronic Resource
    Effect of the phosphodiesterase inhibitor 4-(3-cyclopentyloxy-4-methoxyphenyl)-2-pyrrolidone (ZK 62711) on gastric secretion and gastric mucosal cyclic AMP (1978)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 304 (1978), S. 69-75 
    Details
    ISSN: 1432-1912
    Keywords: Gastric secretion ; Cyclic AMP ; Phosphodiesterase inhibitor ; Rat ; Guinea pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effect of the phosphodiesterase inhibitor 4-(3-cyclopentyloxy-4-methoxyphenyl)-2-pyrrolidone (ZK 62711) on gastric secretion and the cyclic AMP system of the gastric mucosa was studied in rats and guinea pigs. In rats, 0.03–0.3 μmoles/kg ZK 62711 i.v. stimulated acid and pepsin secretion in a dose-dependent manner and 0.03 μmoles/kg i.v. enhanced the effect of histamine. In guinea pigs no reproducible stimulation was found after intravenous injections of ZK 62711. The stimulation of gastric secretion in the rat by 0.3 μmoles/kg ZK 62711 i.v. was not affected by vagotomy but was totally inhibited by 10 μmoles/kg cimetidine i.v. The structurally related phosphodiesterase inhibitor, 4-(3-butoxy-4-methoxybenzyl)-2-imidazolidine (Ro 20-1724), at the dose of 3.3 μmoles/kg i.v. stimulated gastric secretion in anaesthetised rats to a similar extent as 0.3 μmoles/kg ZK 62711 i.v. The content of cyclic AMP in the rat gastric mucosa in vivo was slightly increased by 10 μmoles/kg ZK 62711 i.v, whereas lower doses did not change it. Accumulation of cyclic AMP in the rat gastric mucosa by 50 μmoles/kg histamine i.v. was enhanced by simultaneous injections of 3.3 μmoles/kg ZK 62711 i.v. In rat gastric tissue slices in vitro 1–50 μM ZK 62711 increased the level of cyclic AMP but 100 μM histamine had no effect in the absence or presence of ZK 62711. In gastric mucosal slices of the guinea pig 10 and 50 μM ZK 62711 increased the cyclic AMP content which effect was inhibited by 100 μM cimetidine and enhanced the stimulatory effect of 100 μM histamine on cyclic AMP. The activity of soluble cyclic AMP phosphodiesterase was inhibited by ZK 62711 in the rat (IC50=18 μM) and guinea pig gastric mucosa (IC50=1.5 μM). Adenylate cyclase was not affected in the homogenate of the guinea pig gastric mucosa. The results indicate that the phosphodiesterase inhibitor ZK 62711 which increases cyclic AMP levels in the gastric mucosa in vivo and in vitro, is a potent stimulator of gastric acid secretion.
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    URL: http://dx.doi.org/10.1007/BF00501379
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  • 45
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    Electronic Resource
    Effect of castration and testosterone administration on the neuromuscular junction in the levator ani muscle of the rat (1978)
    Springer
    Cell & tissue research 189 (1978), S. 155-166 
    Details
    ISSN: 1432-0878
    Keywords: Levator ani muscle ; Rat ; Neuromuscular junction ; Castration ; Testosterone effect
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the neuromuscular junction (n.m.j.) of the androgen-sensitive levator ani muscle was studied in normal adult male rats, in 8-month-old rats castrated at the age of one month and in castrated rats treated with testosterone propionate (TP). Castration does not result in significant changes of the n.m.j. The density of synaptic vesicles and the postsynaptic junctional folds remain practically normal in spite of marked atrophy of the muscle. TP administration for 7 days results in marked changes in preand postsynaptic structures. There is slow progressive depletion of synaptic vesicles, appearance of cisternae and coated vesicles in axon terminals, and coalescence of coated vesicles with the plasma membrane. Coated vesicles are also found inside Schwann cells and among junctional folds. Dense core vesicles appear both in the axon terminals and in the postsynaptic area. Collateral sprouting of terminal axons with the formation of new immature junctions is observed. After 35 days of TP administration depletion of synaptic vesicles continues. Glycogen β-particles, mostly freely dispersed, occasionally seen in axon terminals 7 days after TP administration, subsequently increase in number. In the endplate zone of the muscle fibre increased protein synthesis is indicated by a rapid increase in ribosomes and irregularly located myofilaments and myofibrils. The appearance of n.m.j. after testosterone administration resembles that described after nerve stimulation; the degree of change is however less pronounced.
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    URL: http://dx.doi.org/10.1007/BF00223126
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  • 46
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    Electronic Resource
    Influence of maternal adrenalectomy on the ultrastructure of the adrenal gland in neonatal rats (1978)
    Springer
    Cell & tissue research 189 (1978), S. 277-286 
    Details
    ISSN: 1432-0878
    Keywords: Maternal adrenalectomy ; Rat ; Influence on the adrenals of newborn animals ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Maternal adrenalectomy at 7 or 14 days of gestation produced increased cell necrosis within zona reticularis cells on the day of birth and at 24 or 48 h after birth. Small remnants or large portions of adrenocortical cells were present within macrophages. In otherwise normal adrenocortical cells, lipid droplets were incorporated within some mitochondria. Autophagocytosis of single mitochondria was observed within adrenocortical cells. Undoubtedly ultrastructural changes represent stimulation of adrenocortical cells in neonatal rats in response to maternal adrenalectomy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00209277
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  • 47
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    Electronic Resource
    Effects of hormone-releasing stimuli on the area of the perivascular space in the neural lobe of the rat (1978)
    Springer
    Cell & tissue research 191 (1978), S. 501-506 
    Details
    ISSN: 1432-0878
    Keywords: Neurohypophysis ; Ultrastructure ; Perivascular space ; Hormonerelease ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Neural lobes from rats subjected to neurohypophysial hormone-releasing stimuli were examined electron microscopically following fixation in 4 % tannic acid in 2.5 % glutaraldehyde. This fixation allowed the delineation of the perivascular space in the neural lobe tissue. Measurement of the area of the perivascular space showed that it was significantly increased in the rats subjected to vagal stimulation and intraarterial calcium ions compared to the control rats. The rats which had been subjected to haemorrhage as a hormonereleasing stimulus did not show any significant change in the area of the perivascular space. The significance of these findings in relation to hormone release is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219812
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  • 48
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    Electronic Resource
    Intercellular attachments between calcified collagenous tissue forming cells in the rat (1978)
    Springer
    Cell & tissue research 191 (1978), S. 507-512 
    Details
    ISSN: 1432-0878
    Keywords: Odontoblasts ; Osteoblasts ; Cementoblasts ; Intercellular attachments ; Electron microscopy (SEM/TEM) ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Osteoblasts of the young rat cranium, and cementoblasts and odontoblasts of young rat molars were prepared by ethanol freeze-fracture prior to critical point drying for scanning electron microscopy (SEM) as well as conventional transmission electron microscopy (TEM) techniques. Critical point drying causes shrinkage which separates the lateral intercellular contacts between neighbours in the same sheet in the case of cementoblasts and osteoblasts, but not those between odontoblasts. These differences are considered to be of functional significance and need to be taken into consideration when formulating theories of calcium influx into the mineralizable matrix of the respective tissues.
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    URL: http://dx.doi.org/10.1007/BF00219813
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  • 49
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    Electronic Resource
    Fine structure of the palisade zone of the rat median eminence as revealed by freeze-fracturing (1978)
    Springer
    Cell & tissue research 191 (1978), S. 513-523 
    Details
    ISSN: 1432-0878
    Keywords: Median eminence ; Rat ; Freeze-fracture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Nerve terminals in the palisade zone of the rat median eminence were investigated with freeze-fracture electron microscopy. Fracture face P of the specific terminals showed two populations of intramembranous particles (IMP): a large and a small variety. The large IMP-s often formed small irregular clusters. In nerve terminals the total number of both populations of IMP-s was considerably less than that found on P membrane faces of ependymal feet. On fracture face E of the nerve terminals, the number of IMP-s was about a quarter of that seen on fracture face P. On both fracture faces of most terminals a few small round impressions (or elevations respectively) were found which may be interpreted as broken necks of either exo- or endocytotic vesicles. Neither gap nor tight junctions occurred at lateral membranes of the specific axon terminals. Similarly, no membrane specializations were observed with freeze-fracturing on membrane areas adjacent to the basement membrane. The findings are discussed in relation to a possible exocytosis mechanism of the hypothalamic releasing and inhibiting hormones.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219814
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  • 50
    Electronic Resource
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    The reversible effect of colchicine on the taste bud cells of the central circumvallate papilla in the rat (1978)
    Springer
    Cell & tissue research 192 (1978), S. 67-76 
    Details
    ISSN: 1432-0878
    Keywords: Taste buds ; Circumvallate papillae ; Colchicine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary It is believed that differentiation and maintenance of taste buds in vertebrates is dependent on the trophic function of their sensory nerve supply. In the present work colchicine was injected into the circumvallate papilla of the rat. This produced a reversible blockade of neuroplasmic transport and disappearance of taste buds. Colchicine inhibited the further differentiation of bud cells, but apparently did not change the life cycle of the cells present already at the time of injection. It is speculated that the neurotrophic factors in this particular cell system are effective to induce cell differentiation only.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00231023
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  • 51
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    A determination of the volumes of the layers of the rat hippocampal region (1978)
    Springer
    Cell & tissue research 188 (1978), S. 345-359 
    Details
    ISSN: 1432-0878
    Keywords: Hippocampal subfields ; Rat ; Volumes ; Timm stain
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The absolute volumes of the hippocampal and subicular cortical layers in the rat were determined. The boundaries of the various layers were defined on series of sections made through the entire hippocampal region of five rats and stained according to the Timm sulfide silver technique. Coordinates representing the boundaries of the layers on selected sections were fed into a mini-computer programmed to calculate the volume of the layers from the areas of the profiles and the distances between the sections. The distribution of the layers indicates that they constitute the same proportion of the volume of the dorsal and ventral divisions of the hippocampal region, with the exception of the structures lying in regio inferior and regio superior. Although the combined regio superior and regio inferior components of the layers of Ammon's horn occupy the same percentage of the volume of the dorsal and ventral hippocampal regions, the regio superior components occupy a larger percentage of Ammon's horn in the dorsal region than they do in the ventral region. The inter-animal variations in the volumes of the various layers indicate that it is possible to describe quantitatively the subdivisions of the hippocampal region with a precision that is compatible with comparative studies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219777
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  • 52
    Electronic Resource
    Electronic Resource
    Quantitative observations of the effect of sex-steroids on the postnatal development of LH-cells (1978)
    Springer
    Cell & tissue research 188 (1978), S. 491-496 
    Details
    ISSN: 1432-0878
    Keywords: Castration ; LH-cells ; Rat ; Development ; Sex-steroids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of sex-steroids on the LH-cell development in neonatal rats were studied. The cells were stained immunohistochemically by applying anti-HCG serum. On the second day after birth some of the animals of both sexes were gonadectomized and simultaneously injected with testosterone or estradiol (50 or 200 μg). The remaining animals were either gonadectomized or injected with either one of the sex-steroids. The LH-cell numbers in each group were determined on the 12th day of age from serially cut histological sections of the pituitary. In castrated males the number of LH-cells was about twice that of the intact animals. In the so-called sex-zone, LH-cells tended to be hypertrophied in castrates. These alterations in the appearance of LH-cells did not occur after ovariectomy. In gonadectomized animals injected with sexsteroids (200 μg), the cells were markedly reduced in number and size, both in males and females. Testosterone injection (50 μg) into intact newborn animals also suppressed the numerical development of LH-cells, especially in females. These alterations were particularly evident in the sex-zone in both sexes. Thus the present findings show that sex-steroids may be involved in sexual differences in morphological development of LH-cells in newborn rats.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219786
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  • 53
    Electronic Resource
    Electronic Resource
    Investigations into the mechanism of hormone release by rat adrenocortical cells (1978)
    Springer
    Cell & tissue research 189 (1978), S. 403-407 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal gland ; Rat ; Vinblastine ; Corticosterone ; Exocytosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Vinblastine treatment blocks corticosterone release from rat adrenal zona fasciculata without impairing hormone synthesis, and induces the formation of acid phosphatase-positive granular clumps at the juxta-sinusoidal pole of the cells. Autoradiography shows that ACTH administration to vinblastine-treated animals mobilizes the 3H-cholesterol stored in the lipid droplets and leads to a noticeable labelling of the granular clumps. The possible significance of these granules is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00209129
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  • 54
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    Electronic Resource
    Primary cultures of dispersed cells of rat pineal gland (1978)
    Springer
    Cell & tissue research 188 (1978), S. 285-297 
    Details
    ISSN: 1432-0878
    Keywords: Pineal gland ; Rat ; Organ culture ; Indole metabolism ; Ultrastructural morphology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In vitro indole metabolism and ultrastructural morphology of the pineal gland of male rats were examined. A comparison of the effect of norepinephrine stimulation on indole synthesis in whole cultured glands and preparations of dispersed pineal cells is discussed. Our studies on the performance of dispersed cells during the first 24 h after preparation indicate a strong dependence of pineal cells upon physical attachment to the culture dish and probably also on cell-to-cell contact.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00222638
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  • 55
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    Electronic Resource
    Influence of autonomic denervation upon the kinetics of the ileal epithelium of the rat (1978)
    Springer
    Cell & tissue research 192 (1978), S. 285-297 
    Details
    ISSN: 1432-0878
    Keywords: Intestinal epithelium ; Rat ; Kinetics ; Autonomic denervation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effect of autonomic denervation upon the kinetics of the ileal epithelium of rats was studied by tracing 3H-thymidine labelled nuclei and counting mitotic figures and goblet cells. Counts of labelled nuclei and goblet cells provided information about cell migration along the intestinal epithelium. The mitotic index and turnover time of this population were calculated from the mitotic figures counts. Comparing denervated animals with sham operated controls, it was possible to conclude that autonomic denervation, either sympathectomy or parasympathectomy results in a decrease in mitotic activity. As a result of lower mitotic activity in the crypts, the turnover time increases and there is a delay in the migration of cells from the crypts towards the villi. Sympathectomy causes an early short-lived effect upon the kinetics of the crypt cell population, since after 27 h there is a tendency to normality. Parasympathectomy produces a slower but continuous decline in mitotic activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220746
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  • 56
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    Resting values of left ventricular work to coronary blood flow ratio in rats exposed to intermittent high altitude hypoxia and swimming (1978)
    Springer
    European journal of applied physiology 39 (1978), S. 173-179 
    Details
    ISSN: 1439-6327
    Keywords: Exercise ; Altitude ; Left ventricular work ; Myocardial blood flow ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Total hemodynamic values and left ventricular blood flow were studied using Sapirstein's method of 86Rb uptake in female rats 24 h after a last exposure to high altitude. A simulated altitude of 1350 m was used, initial exposure being for 30 min, gradually increased by 30 min daily up to 330 min daily for 5 days a week; the total number of exposures was 32. In another animal group the hypobaric exposure was combined with swimming in water at 37
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00421344
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  • 57
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    Rasterelektronenmikroskopische Studien am Epithel der Plica vocalis von männlichen Albinoratten (1978)
    Springer
    European archives of oto-rhino-laryngology and head & neck 220 (1978), S. 201-212 
    Details
    ISSN: 1434-4726
    Keywords: Plica vocalis ; Epithelial surface ; Rat ; Extrapulmonary airway epithelium ; Scanning electron microscopy ; Stimmbänder ; Epitheliale Oberfläche ; Ratte ; Larynxepithel ; Rasterelektronenmikroskopie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Das Stimmbandepithel ausgewachsener männlicher Albinoratten wird rasterelektronenmikroskopisch untersucht. Seine Oberflächenstruktur wird mit jener des Epithels auf der Plica ventricularis und im Recessus ventricularis verglichen. Charakteristischerweise zeigen die Zellen im Epithel über den Stimmbändern einen dichten, lückenlosen Besatz mit Mikrovilli. Die Übergänge des Stimmbandepithels in die benachbarten Larynxabschnitte wird dokumentiert. Besondere Aufmerksamkeit wird dem Auftreten von Mikroleisten auf den apikalen Zellpolen im Larynxepithel gewidmet, die bisher als charakteristische Struktur für das Stimmbandepithel gewertet wurden.
    Notes: Summary The epithelial surface of the Plica vocalis in adult male rat is studied by scanning electron microscopy. It's structure is compared with that of the plica and of the recessus ventricularis. The transition of the epithelium in the plica vocalis to the epithelium of the joining parts of the larynx is documented. Special attention is paid to the occurrence of microridges at the apical poles of epithelial cells in the larynx. Up to now microridge cells have been said to be characteristic for the plica vocalis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00457488
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  • 58
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    Electronic Resource
    Masthead (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978) 
    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.19781110101
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  • 59
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    Bestimmung der Aktivierungsparameter bei Spironorcaradien-Spirocycloheptatrien-Gleichgewichten durch Linienformanalyse von 1H- und 13C-NMR-Spektren (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1-12 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Determination of Activation Parameters of Spironorcaradiene-Spirocycloheptatriene Equilibria by Line Shape Analysis of 1H and 13C NMR SpectraLine shape analysis of 1H and 13C NMR spectra is used for the determination of activation parameters of the valence isomerization of substituted spironorcaradienes/spirocycloheptatrienes 5 ⇌ 6. Whereas the values obtained for the dibenzo-spironorcaradienes 5a, b are comparable with the data of simple norcaradiene derivatives, those of tetrachloro derivatives 5c, d show considerable differences.
    Notes: Die Linienformanalyse der 1H- und 13C-NMR-Spektren wird zur Bestimmung der Aktivierungsparameter der Valenzisomerisierung von verschieden substituierten Spironorcaradienen zu Spirocycloheptatrienen 5 ⇌ 6 herangezogen. Während die Aktivierungsparameter bei Dibenzospironorcaradienen 5a, b vergleichbar sind mit denen der einfachen Norcaradienderivate, treten bei den Daten der Tetrachlorderivate 5c, d erhebliche Abweichungen auf.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110102
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  • 60
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    Electronic Resource
    Allylradikale mit Bicyclo[3.2.1]octan-Gerüst, ein Beitrag zum Problem homokonjugativer Wechselwirkungen (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 42-55 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Allyl Radicals with Bicyclo[3.2.1]octane Skeleton, a Contribution to the Problem of Homoconjugative InteractionsThe ESR spectra of allyl radicals with bicyclo[3.2.1]octane skeleton were analyzed in order to investigate the possibility of nonbonding interactions in free radicals. The similarity of the spin density distribution in radicals 7 and 8 demonstrates that 7 has the character of a bicyclic allyl radical. There is no significant interaction between HOMO allyl and LUMO double bond in 7. The same is true for the radical having a fused benzene ring instead of the double bond.
    Notes: Radikale mit Bicyclo[3.2.1]octan-Gerüst wurden ESR-spektroskopisch untersucht, um Aussagen über nichtbindende Wechselwirkungen in Radikalen zu gewinnen. Die Ähnlichkeit der Spindichteverteilung in 7 und 8 zeigt, daß 7 den Charakter eines bicyclischen Allylradikals besitzt. Eine merkliche Wechselwirkung wischen HOMO-Allyl und LUMO-Doppelbindung in 7 existiert nicht. Gleiches gilt, wenn anstelle der Doppelbindung ein Benzolrest anelliert ist. Die experimentellen Befunde werden mit INDO-Rechnungen verglichen.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110104
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  • 61
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    Mechanismus der thermischen Isomerisierung von Thiophosphorsäure-O-2-butenylester-O,O-dimethylester. Kinetische Untersuchung (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 56-64 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Mechanism of the Thermal Isomerisation of O-2-Butenyl O,O-Dimethyl Thiophosphate. Kinetic StudyThe thermal isomerisation of O-2-butenyl O,O-dimethyl thiophosphate (1b) (scheme 3) obeys first order rate law. Solvent polarity does not affect the parameters of activation, but influences a little the rate constants. The kinetic data and the observed “special” salt effect lead to the conclusion that the isomerisation proceeds by a dissociative mechanism. Ion pairs as intermediates are proposed.
    Notes: Die thermische Isomerisierung von Thiophosphorsäure-O-2-butenylester-O,O-dimethylester (1b) (Schema 3) verläuft nach einem Geschwindigkeitsgesetz 1. Ordnung. Die Polarität des Mediums beeinflußt nicht die Aktivierungsparameter und übt lediglich einen minimalen Einfluß auf die Geschwindigkeitskonstanten aus. Die kinetischen Daten und der festgestellte „spezielle“ Salzeffekt lassen den Schluß zu, daß diese Isomerisierung einem intramolekularen ionischen Mechanismus folgt. Als ionische Zwischenstufe werden Ionenpaare postuliert.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110105
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  • 62
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    Beiträge zur Chemie des Phosphors, 73: 1,2-Diphenyldiphosphan (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1210-1216 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Chemistry of Phosphorus, 73: 1,2-Diphenyldiphosphane1,2-Diphenyldiphosphane (1) is formed, contrary to results given in the literature, by the reaction of KHPPh with 1,2-dibromoethane. Pure 1 is obtained by hydrolysis or alcoholysis of Me3Si(Ph)P-P(Ph)SiMe3 in the dark. It is stable at - 30°C. 1 disproportionates at room temperature to give PhPH2, higher homologues of the series H2[PPh]n, especially H2[PPh]3, and cyclic phenylphosphanes [PPh]n, mainly [PPh]5. These rearrangements are accelerated by light, phosphides, and strong acids and bases. With K(Ph)P—P(Ph)K, Me3Si(Ph)P—P(Ph)SiMe3, and P2Ph4 1 reacts to give the asymmetric diphosphanes K(Ph)P—P(Ph)H, Me3Si(Ph)P—P(Ph)H, and Ph2P—P(Ph)H, respectively. The NMR, IR, and Raman spectra are discussed.
    Notes: 1,2-Diphenyldiphosphan (1) wird - entgegen Literaturangaben - bei der Reaktion von KHPPh mit 1,2-Dibromethan gebildet. Reines 1 ist durch Hydrolyse oder Alkoholyse von Me3Si(Ph)P - P(Ph)SiMe3 unter Lichtausschluß erhältlich und bei - 30°C beständig. Es disproportioniert bei Raumtemperatur in PhPH2, höhere Homologe der Reihe H2[PPh]n  -  insbesondere H2[PPh]3 - und cyclische Phenylphosphane [PPh]n  -  vor allem [PPh]5. Diese Umlagerungen werden durch Licht, Phosphide sowie starke Säuren und Basen beschleunigt. Mit K(Ph)P—P(Ph)K, Me3Si(Ph)P—P(Ph)SiMe3 oder P2Ph4 reagiert 1 zu den unsymmetrischen Diphosphanen K(Ph)P—P(Ph)H, Me3Si(Ph)P—P(Ph)H bzw. Ph2P—P(Ph)H. Die NMR-, IR- und Raman-Spektren von 1 werden diskutiert.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110338
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  • 63
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    Organische Synthesen mit Übergangsmetallkomplexen, 6: Ketenimin-Synthese via Ketenimin-Komplexe, Isocyanid-Carben-Addition sowie Ketenimin-Carben-Umlagerung in Metallkomplexen (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1223-1227 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Organic Syntheses by Means of Transition Metal Complexes, 6: Synthesis of Ketenimines via Ketenimine Complexes, Isocyanide Carbene Addition and Ketenimine Carbene Rearrangement in Metal ComplexesTransition metal carbene complexes of the Fischer type, e. g. pentacarbonyl(methoxymethyl-carbene)chromium(0), add isocyanides to give ketenimine complexes (1). Ligand displacement by excess isocyanide affords ketenimines (3), which can be isolated in good yields. In contrast to free ketenimine, the nucleophilic attack on ketenimine coordinated to a metal occurs at the terminal carbon atom leading to carbene complexes. The structures of the ketenimine complexes of chromium (1) and tungsten (2), the product of isomerization (5)(2) of the chromium complex, and the products formed by addition of methanol or water (6 and 7, resp.)(2) are discussed, using 13C NMR data.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110341
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  • 64
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    Masthead (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978) 
    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.19781110401
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  • 65
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    Polycyclische Verbindungen, X: Ein einfacher Zugang zu (partiell hydrierten) funktionalisierten Benz[a]anthracenen (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1233-1238 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Polycyclic Compounds, X: A Facile Synthesis of (Partially Hydrogenated) Benz[a]anthracenes with Functional GroupsThe hexa- and decahydrobenz[a]anthracenes 3 and 5 are available in a one step synthesis by Diels-Alder reaction of the tetrahydrobenzo[b]furans 2 with 2,3-didehydronaphthalene (1) or with the naphthalene-endoxide 4. The interconversions 3 → 6, 7 and 8 and 5 → 9 show that many hydroxy- and oxosubstituted (partially hydrogenated) benz[a]anthracenes can be obtained from the primary adducts 3 and 5.
    Notes: Die Hexa- und Decahydrobenz[a]anthracene 3 und 5 sind in einem einstufigen Verfahren durch Diels-Alder-Reaktionen der Tetrahydrobenzo[b]furane 2 mit 2,3-Didehydronaphthalin (1) bzw. mit dem Naphthalin-endoxid 4 zugänglich. Die Reaktionsfolgen 3 → 6, 7 und 8 sowie 5 → 9 zeigen die vielfältigen Abwandlungsmöglichkeiten der Primäraddukte 3 und 5 zu hydroxy- und oxo-substituierten (partiell hydrierten) Benz[a]anthracenen auf.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110402
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  • 66
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    Vinylkationen, 26: Synthese und Solvolyse von Vinylfluoriden (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1253-1263 
    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, 26: Syntheses and Solvolyses of Vinyl FluoridesThe vinyl fluorides 5-8 were prepared by treatment of the corresponding olefins with BrF and subsequent dehydrobromination. The solvolysis reactions in various solvents were studied. The products and their rates of solvolysis measured under different conditions point to a vinyl cation mechanism of the solvolysis reactions.
    Notes: Die Vinylfluoride 5-8 wurden durch Umsetzung der entsprechenden Olefine mit BrF und sich anschließende Dehydrobromierung dargestellt und die Solvolysereaktionen in mehreren Lösungsmitteln untersucht. Die Reaktionsprodukte sowie die unter verschiedenen Bedingungen gemessenen Solvolysegeschwindigkeiten deuten auf einen Verlauf der Solvolyse über Vinylkationen.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110405
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  • 67
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    Bicyclofulvene, IV: Synthesen von Methylentricyclo[4.2.1.02,5]nonan- und -tricyclo[3.2.1.02,4]octan-Derivaten (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1264-1274 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Bicyclofulvenes, IV: Syntheses of Methylenetricyclo[4.2.1.02,5]nonane- and -tricyclo[3.2.1.02,4]octane DerivativesThe synthesis of 9-methylenetricyclo[4.2.1.02,5]nonane (3), 8-methylenetricyclo[3.2.1.02,4]octane (2) and their derivatives as well as that of methylenehomocubane (37) and 9-methylenepentacyclo-[4.3.0.02,4.03,8.05,7]nonane (38) is described.
    Notes: Die Darstellung von 9-Methylentricyclo[4.2.1.02,5]nonan (3), 8-Methylentricyclo[3.2.1.02,4]octan (2) und ihrer Derivate, sowie von Methylenhomocuban (37) und 9-Methylenpentacyclo-[4.3.0.02,4.03,8.05,7]nonan (38) wird beschrieben.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110406
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    Synthese des 6-Desoxycryptosporins und verwandter Verbindungen (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1284-1293 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of 6-Deoxycryptosporin and Related CompoundsThe cis-hydroxylation of naphthopyran 5 yields the ketol 9 as the main product. Furthermore the epimeric ketol 11 and the hydroxylated quinones 2 and 13 can be isolated. Product 2 is the 6-deoxy compound of naturally occuring cryptosporin (1). The stereochemistry of the hydrogenation of the ketol 9 and of the reduction with sodium boron hydride and diisobutylaluminium hydride is reported.
    Notes: Die cis-Hydroxylierung des Naphthopyrans 5 liefert als Hauptprodukt das Ketol 9. Daneben können das epimere Ketol 11 und die hydroxylierten Chinone 2 und 13 isoliert werden. Das Syntheseprodukt 2 ist die 6-Desoxy-Verbindung des Naturstoffs Cryptosporin (1). Über die Stereochemie der katalytischen Hydrierung des Ketols 9 und die Reduktion mit Natriumborhydrid und Diisobutylaluminiumhydrid wird berichtet.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110408
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    Einfluß verschiedener Anionen auf die Kinetik der Säurehydrolyse des Tetraaquamono(salicylaldehydato)chrom(III)-Kations (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1315-1322 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Influence of Various Anions on the Kinetics of the Acid Hydrolysis of the Cation Tetraaquamono(salicylaldehydato)chromium(III)The kinetics of the acid hydrolysis of the cation tetraaquamono(salicylaldehydato)chromium(III) in perchloric acid were studied at 70°C at constant ionic strength as a function of various anions added to the system. The hydrolysis is strongly accelerated by oxyanions like sulfate and nitrate, while halide anions like chloride and bromide affect the rate only slightly. The findings are explained on the basis of the „cis-effect“ of the oxyanions. The reaction is interpreted by an associative interchange mechanism (Ia).
    Notes: Die Kinetik der Säurehydrolyse des Tetraaquamono(salicylaldehydato)chrom(III)-Kations in perchlorsaurer Lösung wurde in Abhängigkeit vom Zusatz verschiedener Anionen bei 70°C und konstanter Ionenstärke untersucht. Die Hydrolyse wird durch die Oxyanionen Sulfat und Nitrat stark beschleunigt, während die Halogenid-Ionen Chlorid und Bromid die Reaktionsgeschwindigkeit nur geringfügig erhöhen. Dieses Ergebnis wird mit dem „cis-Effekt“ der Oxyanionen erklärt. Der Reaktionsablauf wird mit einem assoziativen Interchange-Mechanismus (Ia) interpretiert.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110410
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  • 70
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    Heterocyclopolyaromaten, VI: Heterocyclotetraaromaten mit gleichartigen aromatischen Ringgliedern (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1330-1336 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Heterocyclopolyaromatics, VI: Heterocyclotetraaromatics Containing Similar Kinds of NucleiHeterocyclotraaromatics have been unknown hitherto. Now were prepared 4 representatives (6a, 7, 9, 11) with nucleophilic and 1 representative (13b) with electrophilic aromatic ring members. With one exception the cyclisation of the precursors occurred by oxidative coupling.
    Notes: Heterocyclotetraaromaten waren bisher unbekannt. Es wurden 4 Vertreter (6a, 7, 9, 11) mit nucleophilen aromatischen Ringgliedern und 1 Vertreter (13b) mit elektrophilen aromatischen Ringgliedern dargestellt. Mit einer Ausnahme erfolgte die Cyclisierung der Vorstufen durch oxidative Kupplung.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110412
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  • 71
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    Herstellung und synthetische Verwendung von metallierten Dimethylhydrazonen Regio- und stereoselektive Alkylierung von Carbonylverbindungen (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1337-1361 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Generation and Synthetic Use of Metallated Dimethylhydrazones Regio and Stereoselective Alkylation of Carbonyl CompoundsDimethylhydrazones (DMH's) 6-10 of enolizable aldehydes and ketones can be metallated quantitatively in α-position by n-butyllithium and/or lithium diisopropylamide in tetrahydrofuran. The lithio derivatives thus obtained (11-14) are highly reactive carbon nucleophiles. Their application as enolate equivalents is demonstrated via the sequence carbonyl compound, DMH-derivative, metallation, reaction with alkyl halides (→ 16, 18, 19), and cleavage to the α-substituted carbonyl compound (17) in a number of examples. Apart from some special cases, the alkylations occur regiospecificly at the less substituted carbon atom. Cyclohexanone derivatives are selectively axially alkylated, allowing for example the preparation of trans-disubstituted cyclohexanones. An efficient new conversion of dimethylhydrazones to carbonyl compounds under mild conditions (pH 7, room temperature) by oxidative hydrolysis has been developed. Advantages of the procedure are discussed briefly.
    Notes: Dimethylhydrazone (DMH's) 6-10 von enolisierbaren Aldehyden und Ketonen können mit n-Butyllithium und/oder Lithium-diisopropylamid in Tetrahydrofuran quantitativ in α-Stellung metalliert werden. Die so erhaltenen Lithiumderivate 11-14 sind hochreaktive Kohlenstoffnucleophile. Ihre Verwendung als Enolatäquivalente wird über die Sequenz Carbonylverbindung, DMH-Derivat. Metallierung, Reaktion mit Alkylhalogeniden (→ 16, 18, 19) und Spaltung zur α-substituierten Carbonylverbindung (17) an einer Anzahl von Beispielen demonstriert. Die Alkylierungen erfolgen, von Spezialfällen abgesehen, regiospezifisch am weniger substituierten Kohlenstoffatom. Cyclohexanonderivate werden stereoselektiv axial alkyliert, was zur Darstellung von trans-disubstituierten Cyclohexanonen ausgenutzt wird. Zur quantitativen Spaltung der Dimethylhydrazone zurück zu den Carbonylverbindungen unter milden Bedingungen (pH 7, Raumtemperatur) wurde eine neue oxidative Hydrolyse entwickelt. Die Vorteile der Methode werden kurz diskutiert.
    Additional Material: 6 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110413
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    Das Reaktivitäts-Selektivitätsprinzip, 2: Die Anwendung des Reaktivitäts-Selektivitätsprinzips auf die Sulfonsäureamidbildung (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1384-1394 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Reactivity-Selectivity Principle, 2: Application of the Reactivity-Selectivity Principle to the Formation of SulfonamidesWhen sulfonyl chlorides 1 and anilines 2 react to sulfonamides 3 at a relatively low rate of formation, variation of the solvent has a greater effect than on reactions of more reactive starting compounds (table 1 and 2). On the other hand, selectivity increases with increasing reactivity when substituents X and Y are varied, and only one solvent is used5. This contradictory behaviour of the reactivity-selectivity principle (RSP)(1) for changing solvents and changing substituents can be explained by the opposing influence of substituents X and Y over bond formation and bond cleavage (transition states 4 and 5 in scheme 1). It is concluded that the failure of the RSP does not mean that the Hammond-Postulate does not hold.Selectivity measurements at various temperatures show that the isoselective temperatures (Tis) of these reaction series are in the range of 190°C (table 3 and 5, figure 2).
    Notes: Die Lösungsmittelvariation übt auf kleine Bildungsgeschwindigkeiten der Sulfonsäureamide 3 aus Sulfonsäurechloriden 1 und Anilinen 2 einen größeren Einfluß aus als auf die rascheren Umsetzungen reaktiverer Ausgangssubstanzen (s. Tab. 1 und 2). Im Gegensatz dazu steht der Anstieg der Selektivität mit zunehmender Reaktivität, wenn in einem Solvens die Substituenten X und Y der Sulfonsäurechloride 1 und Aniline 2 variiert werden(5). Dieser Widerspruch zwischen Gültigkeit des Reaktivitäts-Selektivitätsprinzips (RSP)(1) bei Lösungsmittelwechsel und seiner Ungültigkeit bei Substituentenvariation läßt sich mit dem gegenläufigen Einfluß der Substituenten X und Y auf die Bindungsbildung und den Bindungsbruch deuten (s. Übergangszustände 4 und 5 im Reaktionsschema 1). Es wird geschlossen, daß das Versagen des RSP nicht mit einem Versagen des Hammond-Postulats einhergeht.Selektivitätsmessungen bei unterschiedlichen Temperaturen zeigen, daß die isoselektiven Temperaturen (Tis) dieser Reaktionsserien bei ca. 190°C liegen (s. Tab. 3 und 5. Abb. 2).
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110415
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    Selektive Doppelbindungsisomerisierungen unter C-17-Inversion an 20-Methyl-A-nor-pregnadienen (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1404-1412 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Selective Double Bond Isomerizations with C-17 Inversion in 20-Methyl-A-nor-pregnadienesThe A-nor-steroid-diene 3a was prepared from the cyclosteroid 1 as well as from the A-nor-steroid-dienes 2 and 4 by HBr-induced regioselective double bond isomerization. Configurational inversion of the 17β-isopropyl group during isomerization (Δ8(9) or Δ8(14) → Δ14) of 1, 2, and 4, presumably via a spirocyclic intermediate, only occurs under special reaction conditions. 3a was converted into 20-methyl-14β,17α-pregn-4-en-3-one (9a).
    Notes: Aus dem Cyclosteroid 1 wie den A-Nor-Steroid-dienen 2 und 4 wurde durch HBr-induzierte, regioselektive Doppelbindungsisomerisierungen das 17α-konfigurierte A-Nor-Steroid-dien 3a dargestellt. Die Isomerisierungen (Δ8(9) bzw (Δ8(14) → Δ14) verlaufen bei 1, 2 und 4 bei Einhaltung spezieller Reaktionsbedingungen unter Konfigurationsinversion der 17β-Isopropylgruppe, vermutlich über ein spirocyclisches Zwischenprodukt. Aus 3a wurde 20-Methyl-14β,17α-pregn-4-en-3-on (9a) erhalten.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110417
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  • 74
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    Hochenergetische Moleküle, VI: Berechnung zum Zerfallsmechanismus substituierter 1,2-Dioxetane nach der MINDO 3-Methode. Ein Kohlenstoff-Kohlenstoff-Diradikal als möglicher Übergangszustand bei der Thermolyse zu Produkten im elektronischen Grundzustand (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1413-1419 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: High-energetic Molecules, VI: MINDO/3 Calculations on the Thermolysis of 1,2-Dioxetanes. Evidence for a CC Biradical as Transition State of the Fragmentation to Products in the Electronic Ground StateMINDO/3 calculations of the conformation and bond strengths of substituted 1,2-dioxetanes (3-7) show that the O—O bond is strengthened by increasing alkyl substitution. This stabilizes the molecule and increases the concerted nature of the fragmentation. Substituents with lone pairs (OR, F) tend to weaken the C—C bond to the extent that cleavage to ground state products starts with C—C bond breaking.
    Notes: MINDO/3-Berechnungen der Konformation und der Bindungsstärken bei substituierten 1,2-Dioxetanen (3-7) zeigen, daß die O—O-Bindung durch zunehmende Alkylsubstitution gestärkt wird. Damit sollte die Stabilität des Moleküls und der Synchroncharakter des Zerfallsmechanismus zunehmen. Substituenten mit freie Elektronenpaaren (OR, F) hingegen schwächen die C—C-Bindung soweit, daß der Zerfall zu Produkten im elektronischen Grundzustand unter bevorzugtem Öffnen der C—C-Bindung möglich erscheint.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110418
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  • 75
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    Synthese langkettiger, endständig bifunktioneller Alkan- und Alkin-Derivate (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1446-1452 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of Long Chain Terminally Bifunctionalised Alkane and Alkyne DerivativesBy reaction of the Grignard derivative of compound 1 with α,ω-disubstituted alkanes 2-4, 7 and catalysis with Li2CuCl4 compounds 6a, b, 8, 9 are synthesized. The reaction of the lithium salt of alkyne 12 with the dihalogenalkanes 10a, 11b in THF/HMPT followed by hydrolysis gives compounds 14a, b with chains of 38 and 46 carbon atoms. By repetition of this reaction sequence the alkyne derivatives 18a, b with chains of 64 and 72 carbon atoms are obtained.
    Notes: Durch Umsetzung der Grignard-Verbindung von 1 mit den α,ω-disubstituierten Alkanen 2-4, 7 unter Katalyse mit Li2CuCl4 werden die Verbindungen 6a, b, 8, 9 synthetisiert. Die Reaktion des Lithiumsalzes von 12 mit den Dihalogenalkanen 10a, 11b in THF/HMPT und nachfolgende Hydrolyse ergibt die Verbindungen 14a, b mit Ketten von 38 und 46 Kohlenstoffatomen. Durch Wiederholung dieser Reaktionsfolge werden die Alkin-Derivate 18a, b mit Ketten von 64 und 72 Kohlenstoffatomen erhalten.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110422
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  • 76
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    Lichtinduzierte [2 + 2]-Cycloadditionen von Thionen an cyclische Alkene (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1471-1474 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Light-induced [2 + 2] Cycloaddition Reactions of Thiones with Cyclic AlkenesUnder n→π* excitation using sodium light, xanthione (1) combines with acenaphthylene, indene or N-phenyl maleoylimide in good yields with formation of the spirothietane drivatives 3, 7, or 8, respectively. The analogous photoreactions (λ ≍ 400 nm) of the 2-thioparabanate 4 in the presence of indene, benzo[b]furan or N-phenyl maleoylimide proceed with formation of the spirothietanes 6a, b, or 9, respectively. The thietane structures are consistent with spectroscopic data.
    Notes: Bei n→π*-Anregung mit Natrium-Licht vereinigt sich Xanthion (1) mit Acenaphthylen, Inden bzw. N-Phenylmaleinimid in guten Ausbeuten zu den Spirothietan-Derivaten 3, 7 bzw. 8. Die analogen Photoreaktionen (λ ≍ 400 nm) der 2-Thioparabansäure 4 in Gegenwart von Inden, Benzo[b]furan bzw. N-Phenylmaleinimid verlaufen unter Bildung der Spirothietane 6a, b bzw. 9. Spektroskopische Daten sichern die Konstitutionen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110425
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    Cycloadditionsreaktionen von Heterocumulenen, XII: Umsetzung von persubstituierten Isothioharnstoffen mit Isocyanaten (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1475-1485 
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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: Cycloaddition Reactions of Heterocumulenes, XII: Reaction of Persubstituted Isothioureas with IsocyanatesThe isothiourea 1a reacts with the sulfonyl isocyanates 2a-c to give the stable 1,4-dipoles 3a-c, which can be characterized spectroscopically as well as by protonation to yield the ureas 7. For one example (3b) the molecular structure is elucidated by an X-ray structural analysis. The isothioureas 1b-g with bulkier substituents react with 2a, b in a [2 + 2]-cycloreversion to give the isocyanates 5 and the N-sulfonylisothioureas 6. Using (thio)benzoyl isocyanates (2d, e) the same type of reaction leads to the N-(thio)benzoylisothioureas 8.
    Notes: Der Isothioharnstoff 1a reagiert mit den Sulfonylisocyanaten 2a-c zu den stabilen 1,4-Dipolen 3a-c, die sich spektroskopisch sowie durch Protonierung zu den Harnstoffen 7 charakterisieren lassen. An einem Beispiel (3b) wurde die Molekülstruktur durch eine Röntgenstrukturanalyse aufgeklärt. Die höher substituierten Isothioharnstoffe 1b-g setzen sich mit 2a, b in einer [2 + 2]-Cycloreversion zu den Isocyanaten 5 und den N-Sulfonylisothioharnstoffen 6 um. Mit (Thio)-Benzoylisocyanat (2d, e) entstehen nach dem gleichen Reaktionsprinzip N-(Thio)Benzoylisothioharnstoffe 8.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110426
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    Die erstmalige stereoselektive Bildung von 2r-Halogen-3c-dimethylamino-4t-phenylthietan-1,1-dioxiden und 2-Halogen-4-phenyl-2H-thiet-1,1-dioxiden (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1527-1532 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stereoselective Formation of 2r-Halogeno-3c-dimethylamino-4t-phenylthietane 1,1-Dioxides and 2-Halogeno-4-phenyl-2H-thiete 1,1-DioxidesN,N-Dimethyl-(E)-styrylamine (1) reacts with halogen-substituted methanesulfonyl chlorides (2a-e) to give acyclic substituted products (4a-e) and stereoselectively 2r-halogeno-3c-dimethylamino-4t-phenylthietane 1,1-dioxides (3a-c). Cope-elimination from 3a-c produced only the 2-halogeno-4-phenyl-2H-thiete 1,1-dioxides (5a-c). The additional halogenation of 4-phenyl-2H-thiete 1,1-dioxide in the 2-position and the oxidation to the 2-oxo derivative did not succeed.
    Notes: Aus N,N-Dimethyl-(E)-styrylamin (1) und halogensubstituierten Methansulfonylchloriden (2a-e) entstehen neben acyclischen Substitutionsprodukten (4a-e) mit hoher Selektivität die 2r-Halogen-3c-dimethylamino-4t-phenylthietan-1,1-dioxide (3a-c). Durch Cope-Eliminierung aus 3a-c erhält man ausschließlich die 2-Halogen-4-pheny-2H-thiet-1,1-dioxide (5a-c). Die nachträgliche Einführung von Halogen in die 2-Position von 4-Phenyl-2H-thiet 1,1-dioxid gelingt ebensowenig wie dessen Oxidation zum 2-Oxoderivat.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110433
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    Neue heteroanellierte Benzo[b]thiophen-1,1-dioxide (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1521-1526 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: New Hetero Anellated Benzo[b]thiophene 1,1-Dioxides2-Benzoyl-3-chlorobenzo[b]thiophene 1,1-dioxide reacts with semicarbazide. 4-methylbenzamidrazone, 1,8-diaminonaphthaline to give 1c-e, with KSCN to give the isothiocyanate 1g. The hydrolysis of 1g and also the reaction of ammonia with 1a leads to 1h. 1a reacts with sodium-azide to form 2b, and with hydrazine to form 2a. The hydrolysis of 1d results in 3. Ethyl β-amino-crotonate condenses with 1a to the pyridine derivative 4. The pyrimidine compounds 6a-c can be prepared by the reaction of 1a with guanidine, benzamidine and acetamidine respectively. 1g reacts with aniline to give 5, o-phenylenediamine, ethylenediamine and N-methylethylenediamine on reaction with 1a give the diazepine derivatives 8a-c. The reaction of 1a with o-aminothiophenol gives the benzothiazole derivative 9.
    Notes: 2-Benzoyl-3-chlorbenzo[b]thiophen-1,1-dioxid (1a) reagiert mit Semicarbazid, 4-Methylbenz-amidrazon, 1,8-Diaminonaphthalin zu 1c-e, mit KSCN zu dem Senföl 1g: durch Hydrolyse von 1g erhält man 1h, zu dem man auch durch Umsetzung von 1a mit Ammoniak gelangt. 1a reagiert mit Natriumazid zu 2b, mit Hydrazin zu 2a. Saure Hydrolyse von 1d führt zur Verbindung 3. 3-Aminocrotonsäure-ethylester kondensiert mit 1a zum Pyridinderivat 4: mit Guanidin, Benzamidin und Acetamidin erhält man die Pyrimidinabkömmlinge 6a-c. 1g reagiert mit Anilin zu 5, 1a mit o-Phenylendiamin, Ethylendiamin und N-Methylethylendiamin zu Diazepinverbindungen 8a-c, mit o-Aminothiophenol zum Benzothiazol 9.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110432
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    Über die Bildung von Oxirenen aus cyclischen α-Diazoketonen (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1549-1557 
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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: On the Formation of Oxirenes from Cyclic α-DiazoketonesThe reactions following the nitrogen elimination from 2-diazo-12-methyl-1-cyclododecanone (15) are studied. In the intermediate 12-membered α-oxocarbene 17 the first example of a photochemically and thermally induced 1,2-shift of oxygen in a cyclic α-oxocarbene is described. The rearrangement involves the condensed oxirene system 18. The occurrence of the two isomeric α-oxocarbenes 17 and 17′ is demonstrated by the subsequent 1,2-hydrogen rearrangement to isomeric α,β-unsaturated ketones (19, 20 and 19′, 20′). In contrast no oxirene participation is found in the silver oxide-catalysed reaction.
    Notes: Die Folgereaktionen nach der Stickstoff-Abspaltung aus 2-Diazo-12-methyl-1-cyclododecanon (15) werden untersucht. Am intermediären 12-Ring-α-oxocarben 17 wird das erste Beispiel einer photochemisch und thermisch ausgelösten 1,2-Sauerstoffverschiebung in cyclischen α-Oxocarbenen beschrieben. Die Umlagerung verläuft über das kondensierte Oxiren-System 18. Das Auftreten der beiden isomeren α-Oxocarbene 17 und 17′ wird durch die nachfolgende 1,2-Wasserstoff-verschiebung zu isomeren α,β-ungesättigten Ketonen (19, 20 und 19′, 20′) belegt. Im Gegensatz dazu wird bei der silberoxid-katalysierten Reaktion keine Oxiren-Beteiligung gefunden.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110436
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    Conformational preferences of substituted cyclopentadienyl and heterocyclopentadienyl complexes (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1578-1590 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Über die konformative Präferenz in substituierten Cyclopentadienyl- und Heterocyclopentadienyl-KomplexenMO-Berechnungen ergeben erhebliche Barrieren für die internen Rotationen in Thiadiborolen-Fe(CO)3- und Diazaborolen-Cr(CO)3-Komplexen. Die Gleichgewichtsgeometrien der zwei Moleküle sollten verschieden sein. Eine MO-Fragmentanalyse erklärt diese Ergebnisse und führt darüberhinaus zu einer ganz allgemeinen Analyse der Rotationsbarrieren in Heterocyclopentadienyl- und substituierten Cyclopentadienyl-ML3- und -ML2-Komplexen. Für letztere wird ein gleitender Übergang von η5- nach η2-Koordination vorhergesagt.
    Notes: Molecular orbital calculations indicate substantial barriers to internal rotation in thiadiborolene-Fe(CO)3 and diazaborolene-Cr(CO)3 complexes. The equilibrium geometry of the two molecules should also differ. A fragment analysis explains these results and leads to a general analysis of rotational barriers in heterocyclopentadienyl and substituted cyclopentadienyl-ML3 and -ML2 complexes. In the latter an interesting “slipping” from η5 toward η2 coordination is predicted.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110439
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  • 82
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    Cycloheptatriene and fulvene Cr(CO)3 complexes (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1591-1602 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cycloheptatrien- und Fulven-Cr(CO)3-KomplexeIm Tricarbonylchrom(0)-Komplex von 1,6-Methano[10]annulen und in einigen verwandten Komplexen nimmt die Cr(CO)3-Einheit verglichen mit allen anderen Hexatrien-Cr(CO)3-Systemen eine anomale Orientierung relativ zum Polyen ein. Eine theoretische Analyse dieses Problems zeigt, daß diese Vorzugskonformation eng mit der Cycloheptatrien-Norcaradien-Valenztautomerie zusammenhängt. Mögliche Wege, die Rotationsbarriere in derartigen Komplexen zu beeinflussen, werden aufgezeigt. Vorzugskonformation, Rotationsbarriere und Abknicken der exocyclischen Methylengruppe in Tricarbonyl(η6-fulven)chrom(0) werden diskutiert und die Analyse wird auf die analogen Benzyl-Cr(CO)3- und Cyclobutadiencarbinyl-Fe(CO)3-Kationen ausgedehnt. Die Konformation dieser Komplexe wird solchen gegenübergestellt, die zwei Elektronen mehr enthalten.
    Notes: 1,6-Methano[10]annulene-Cr(CO)3 and several related complexes adopt an anomalous orientation of the Cr(CO)3 unit with respect to the polyene, compared to all other hexatriene-Cr(CO)3 complexes. A theoretical analysis of this problem shows that these conformational preferences are closely related to the cycloheptatriene-norcaradiene valence tautomerism. Several strategies for influencing the barrier to internal rotation in these complexes are presented. An analysis of the conformational preference, rotational barrier, and bending of the exocyclic methylene group in fulvene-Cr(CO)3 is also discussed. This is extended to the analogous benzyl-Cr(CO)3 and cyclobutadiene-carbinyl-Fe(CO)3 cations. Finally, the orientations of these complexes are contrasted to those containing two more electrons.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110440
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  • 83
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    Chlorierung von N-substituierten Carbonsäureamiden (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1619-1626 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Chlorination of N-Substituted CarboxamidesN,N′-Dimethyl- (1a-c). N,N,N′,N′-tetramethyl- (9a-c), and N,N′-dimethyl-N,N′-diphenyl-diamides are transformed into the corresponding bis(chloromethyl)- (2a-c, 13, 14) or tetrakis-(chloromethyl)diamides (10a-c) by chlorination with simultaneous UV-irradiation. Chlorination of N,N′-dimethyldichloromalonamide (1c) with excess chlorine leads to N,N′-bis(dichloro-methylene)dichloromalonamide (5) in good yield. The compounds are characterized by NMR spectra and by substitution reactions. N-(Dichloromethylene)benzamide (15) reacts with dimethyl sulfoxide to give N-benzoyl-S,S-dimethylsulfimide (17), which decomposes thermally in part into N,N-methylenedibenzamide (19).
    Notes: N,N′-Dimethyl- (1a-c), N,N,N,N′-Tetramethyl- (9a-c) und N,N′-Dimethyl-N,N′-diphenyl-diamide werden durch Chlorierung unter UV-Bestrahlung in die entsprechenden Bis(chlormethyl)- (2a-c, 13, 14) bzw. Tetrakis(chlormethyl)diamide (10a-c) übergeführt. Chlorierung von N,N′-Dimethyldichlormalonamid (1c) mit überschüssigem Chlor führt in guter Ausbeute zum N,N′-Bis(dichlormethylen)dichlormalonamid (5). Die Verbindungen werden NMR-spektroskopisch und durch Substitutionsreaktionen charakterisiert. N-(Dichlormethylen)benzamid (15) reagiert mit Dimethylsulfoxid zum N-Benzoyl-S,S-dimethylsulfimid (17), das thermisch teilweise zu N,N′-Methylendibenzamid (19) abgebaut wird.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110442
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  • 84
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    Alkinylverbindungen von Übergangsmetallen, XXXV: Komplexe von Palladium(II)-acetyliden mit 1,2-Bis(diphenylphosphino)ethan (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1627-1631 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Alkynyl Compounds of Transition Metals, XXXV: Complexes of Palladium(II) Acetylides with 1,2-Bis(diphenylphosphino)ethaneThe complexes cis-[Pd(C ≡ CR)2(dpe)] and cis-[Pd(C ≡ CC6H4C ≡ CH-o)(Cl)(dpe)] have been prepared according to the equations (1) and (2) (dpe = (C6H5)2PCH2CH2P(C6H5)2; R = H, C6H5, CH3). The cis-structure of these complexes is confirmed by their IR spectra and by 31P NMR data.  -  The complexes cis-[Pd(C2R)2(dpe)] react with excess KC ≡ CR to give the not quite pure tetrakis(alkynyl)palladates(II), K2[Pd(C2R)4], according to the equation (4). Both types of complexes can be reduced according to (5) or (6) to the palladium(0) complexes K2[Pd(C2R)2] known long ago.
    Notes: Nach den Gleichungen (1) und (2) wurden Komplexe des Typs cis-[Pd(C ≡ CR)2(dpe)] sowie cis-[Pd(C ≡ CC6H4C ≡ CH-o)(Cl)(dpe)] dargestellt (dpe = (C6H5)2PCH2CH2P(C6H5)2; R = H, C6H5, CH3). Die cis-Struktur dieser Verbindungen wird durch ihre IR-Spektren bzw. 31P-NMR-Daten belegt.  -  Die Komplexe cis-[Pd(C2R)2(dpe)] reagieren mit überschüssigem KC ≡ CR gemäß Gleichung (4) zu den nicht ganz reinen Tetrakis(alkinyl)palladaten(II). K2[Pd(C2R)4]. Beide Komplextypen lassen sich gemäß Gleichung (5) oder (6) zu den schon lange bekannten Palladium(0)-Verbindungen K2[Pd(C2R)2] reduzieren.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110443
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  • 85
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    [3.3]-Sigmatrope Umlagerungen an Glycalen und Pseudoglycalen (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1632-1645 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: [3.3]-Sigmatropic Rearrangements at Glycals and Pseudoglycals3,4,6-Tri-O-acetyl-1,2-dideoxy-D-arabino-hex-1-enopyranose (1a) reacts in acetonitrile with sodium azide, potassium thiocyanate and potassium O-ethyl-dithiocarbonate in the presence of boron trifluoride-diethylether to afford the corresponding C-1-substituted 2,3-dideoxy-2-enopyranosyl compounds 2a, 3a, 11a and 11b. They easily rearrange at room temperature to the C-3-substituted glycals 4a, 5a, 12a, and 12b. In case of the azido compounds the rearrangement is reversible and equilibria are established between glycals and pseudoglycals. Similar results are found with other glycals. Allylic rearrangement of glycals can be used to prepare branched chain sugars as is shown by conversion of 14 to 15 and the formation of 18 from 17.
    Notes: 3,4,6-Tri-O-acetyl-1,2-didesoxy-D-arabino-hex-1-enopyranose (1a) reagiert in Acetonitril mit Natriumazid, Kaliumthiocyanat und Kalium-O-ethyl-dithiocarbonat unter Bortrifluorid-Etherat-Katalyse zu den entsprechend in 1-Stellung substituierten 2,3-Didesoxy-2-enopyranosyl-Verbindungen 2a, 3a, 11a und 11b. Sie unterliegen bereits bei Raumtemperatur einer allylischen Umlagerung unter Bildung der 3-substituierten Glycale 4a, 5a, 12a und 12b. Im Falle der Azidoverbindungen sind die Umlagerungen reversibel und führen zu Gleichgewichten zwischen Glycalen und Pseudoglycalen. Ähnliche Ergebnisse werden mit anderen Glycalen erhalten. Durch Allylumlagerung an Glycalen sind auch C-verzweigte Zucker zugänglich, wie durch die Umlagerung von 14 nach 15 und die Bildung von 18 aus 17 gezeigt werden konnte.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19781110444
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  • 86
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    Funktionelle Trimethylphosphinderivate, VII: Ambivalentes Verhalten von Tetrakis(trimethylphosphin) eisen: Zum Verlauf der Reaktion mit CH3I (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1650-1652 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Functional Derivatives of Trimethylphosphine. VII: Ambivalent Behaviour of Tetrakis(trimethylphosphine) iron: Reaction with CH3ITreatment of the title complex 1a ⇌ 1b with CH3I in pentane at ambient temperature yields L4(CH3)Fel(L = P(CH3)3). The reaction is shown to proceed via oxidative addition to the iron(0) isomer 1a. In ether at lower temperature, a reaction with the iron(II) isomer 1b predominates, which leaves its hydridoiron function unchanged. So, a hydridoiron iodide complex is formed, probably by attack on the Fe—C bond.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110446
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  • 87
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    Anellierte 2H-1,3-Oxazin-2-one und -thione (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 314-319 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Fused 2H-1,3-Oxazin-2-ones and -thionesCyclisation of 2-hydroxybenzimidic acid derivatives 1 and 2 by carbonyl reagents yields 2H-1,3-benzoxazin-2-ones 3 and 4. Multinucleous compounds 6 resp. 8 are formed starting with heterocyclic o-hydroxycarboximidic acid derivatives 5 resp. N,N′-bridged amidines 7.
    Notes: Durch Ringschluß von 2-Hydroxybenzimidsäure-Derivaten 1 und 2 mit Carbonyl-Reagenzien werden 2H-1,3-Benzoxazin-2-one 3 und 4 erhalten. Heterocyclische o-Hydroxycarboximidsäure-Derivate 5 bzw. N,N′-überbrückte Amidine 7 liefern die mehrkernigen Analoga 6 bzw. 8.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110130
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  • 88
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    Heterocyclische Siebenring-Verbindungen, XX: Die Kristallstruktur eines 1-Benzothiepin-1-oxids (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 309-313 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Heterocyclic Seven-membered Ring Compounds, XX: Crystal Structure of a 1-Benzothiepin 1- Oxide3,5-Dimethoxy-4-phenyl-1-benzothiepin 1-oxide crystallizes in the rhombic space group P212121. The structure has been determined by X-ray diffraction using direct methods. The seven-membered ring exists in a big vaulted boat conformation with the oxygen of the sulfoxide function in exo-position.
    Notes: 3,5-Dimethoxy-4-phenyl-1-benzothiepin-1-oxid kristallisiert in der rhombischen Raumgruppe P212121. Die Struktur der Verbindung wurde, röntgenographisch mittels direkter Methoden bestimmt. Der Siebenring besitzt eine stark aufgewölbte Bootform mit exo-ständigem Sauerstoff der Sulfoxid-Funktion.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110129
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  • 89
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    Eine entartete Umlagerung des cis-Bicyclo[6.1.0]nona-2,4,6-triens (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 282-298 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A Degenerate Rearrangement of cis-Bicyclo[6.1.0]nona-2,4,6-trieneThe synthesis and the thermal behaviour of the diastereomeric 9-methyl- and 4,9-dimethyl-cis-bicyclo[6.1.0]nonatriene-9-carbonitriles 1a,b and 10a,b are reported. The bicyclo[6.1.0]nonatriene ⇌ bicyclo[6.1.0]nonatriene rearrangement which is degenerate in the cases of 1a and 1b could be detected experimentally with the aid of the dimethyl derivatives 10a and 10b. At 102.5°C ([2H6]benzene) the mutual interconversion 10a ⇌ 11a ⇌ 12a ⇌ 13a and 10b ⇌ 11b ⇌ 12b ⇌ 13b, respectively, proceeds stereospecifically with inversion at the migrating carbon atom C-9 as postulated by Woodward and Hoffmann. Apart from the stereochemical result the concerted nature of this rearrangement is made plausible by the energetic parameter. The difference in the Gibbs energies of activation for the cleavage of the cyclopropane bond C-1 - C-9 in the bicyclo[6.1.0]-nonatriene → bicyclo[4.2.1]nonatriene isomerization 1a → 7a + 7b, 1b → 7a + 7b and in the rearrangement 10a → 11a, 10b → 11b amounts to ca. 7 kcal/mol in each case and suggests an aromatic transition state for the degenerate rearrangement.
    Notes: Synthese und thermisches Verhalten der diastereomeren 9-Methyl- und 4,9-Dimethyl-cis-bicyclo-[6.1.0]nona-2,4,6-trien-9-carbonitrile 1a,b und 10a,b werden beschrieben. Die in den Systemen 1a und 1b entartete Bicyclo[6.1.0]nonatrien ⇌ Bicyclo[6.1.0]nonatrien-Umlagerung konnte am Beispiel der Dimethylderivate 10a und 10b experimentell nachgewiesen werden. Die wechselseitige Umlagerung 10a ⇌ 11a ⇌ 12a ⇌ 13a bzw. 10b ⇌ 11b ⇌ 12b ⇌ 13b erfolgt bei 102.5°C ([D6]Benzol) stereospezifisch mit der von Woodward und Hoffmann postulierten Inversion am wandernden Kohlenstoff C-9. Außer durch das stereochemische Ergebnis wird der synchrone Charakter dieser Umlagerung durch den energetischen Parameter wahrscheinlich gemacht. Der Unterschied der Gibbs-Aktivierungsenergie für die Öffnung der Cyclopropanbindung C-1 - C-9 in der Bicyclo[6.1.0]nonatrien → Bicyclo[4.2.1]nonatrien-Isomerisierung 1a → 7a + 7b, 1b → 7a + 7b und in der Umlagerung 10a → 11a, 10b → 11b beträgt in jedem Fall ca. 7 kcal/mol und legt einen aromatischen Übergangszustand für die entartete Umlagerung nahe.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110127
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    Zum Substituenteneinfluß der Guanidino- und der Guanidiniumgruppe, Teil I: Der Effekt auf die 19F-NMR-Spektren von Fluorbenzolen und auf die aromatische Substitution (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 320-334 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Substituent Effect of the Guanidino and of the Guanidinium Group, Part I: The Effect on 19F NMR Spectra of Fluorobenzenes and on the Aromatic SubstitutionTaft's substituent parameters σ1, and σR are calculated from 19F NMR spectra of N-(fluorophenyl)-guanidines and their salts. The rearrangement of N-nitro-N′-phenylguanidine (1) in strong acid is shown to be an intermolecular nitration of the N-phenylguanidinium cation by NO2⊕. Both o-and p-nitro derivatives are formed at a rate which is but slightly retarded compared to that with benzene.  -  Together with results from 35Cl-NQR spectra(1) and redox potentials of guanidinoquinones(2) the above findings show that the guanidino group exerts only a + M-effect.  -  In addition to the expected  -  I-effect the guanidinium function shows a distinct + M-effect in spite of its positive charge and the reduced charge distribution in the guanidine system.
    Notes: Aus den 19F-NMR-Spektren von N-(Fluorphenyl)guanidinen und ihren Salzen werden die Taftschen σ1- und σR-Werte errechnet. Die Umlagerung des N-Nitro-N′-phenylguanidins (1) in starker Säure verläuft intermolekular als Nitrierung eines N-Phenylguanidinium-Ions durch NO2⊕. Es entstehen o- und p-Nitroderivate mit relativ zu Benzol nur geringfügig reduzierter Geschwindigkeit. -- Zusammen mit 35Cl-NQR-Messungen (1) und der Beeinflussung von Redoxpotentialen bei Guanidinochinonen(2) zeigen diese Befunde, daß die Guanidinogruppe als mesomerer Elektronendonator wirkt.  -  Neben dem erwarteten  -  I-Effekt zeigt die Guanidiniumgruppe trotz ihrer positiven Ladung und der Einschränkung der Mesomerie im Guanidinsystem einen deutlichen + M-Effekt.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110131
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    Thiadiborolen-Komplexe des Chroms und Molybdäns (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 356-360 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thiadiborolene Complexes of Chromium and Molybdenum3,4-Diethyl-2,5-dimethyl-Δ3-1,2,5-thiadiborolene (1) reacts with the hexacarbonyls of chromium and molybdenum photochemically to yield the mono- and bis(thiadiborolene) complexes 2, 3 and 4, 5. The latter exhibit higher thermal and hydrolytical stability than the tetracarbonyl compounds. 4 is also obtained from 1 and (C6H6)Cr(CO)3. From spectroscopic data it is concluded that pentahapto-thiadiborolene complexes and cis arrangement of the CO groups in 4 and 5 are present.
    Notes: 3,4-Diethyl-2,5-dimethyl-Δ3-1,2,5-thiadiborolen (1) reagiert mit den Hexacarbonylen des Chroms und Molybdäns photochemisch zu den Mono- und Bis(thiadiborolen)-Komplexen 2, 3 und 4, 5. Letztere zeigen größere thermische und hydrolytische Stabilität als die Tetracarbonyl-Verbindungen. 4 entsteht auch aus 1 und (C6H6)Cr(CO)3. Aus den spektroskopischen Daten wird auf das Vorliegen von pentahapto-Thiadiborolen-Komplexen und cis-Anordnung der CO-Gruppen in 4 und 5 geschlossen.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19781110133
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  • 92
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    Über Aminosäuren und Peptide, XXIV: Radikalisch und photochemisch initiierte Oxidation von Aminosäurederivaten (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 361-366 
    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, XXIV: Radically and Photochemically Initiated Oxidation of Amino Acid DerivativesIn an atmosphere of oxygen cyclic peptides are photochemically oxidized to mono- and bishydroperoxides (1, 2, 4, 6, 8, 10, 11) in the presence of benzophenone as catalyst. The same products are also formed using radical initiators.
    Notes: Cyclopeptide werden in einer Sauerstoffatmosphäre photochemisch-radikalisch unter Benzophenon-Katalyse zu Mono- und Bishydroperoxiden (1, 2, 4, 6, 8, 10, 11) oxidiert. Die gleichen Produkte entstehen auch bei der Oxidation mit Hilfe von Radikalstartern.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110134
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    Organische Elektrochemie, I: Über die elektrochemische Reduktion von 2,3-Dioxo-1,2,3,4-tetra-hydrochinoxalinen und die Autoxidation der Reduktionsprodukte (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1753-1762 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Organic Electrochemistry, I: Electrochemical Reduction of 2,3-Dioxo-1,2,3,4-tetrahydroquinoxalines and Autoxidation of the Reduction ProductsThe electrochemical reduction of 1-methyl- (2) and 1,4-dimethyl-2,3-dioxo-1,2,3,4-tetrahydro-quinoxaline (3) leads in acidic media in an unusual 4 electron reduction step to 1-methyl- (4) and 1,4-dimethyl-3-oxo-1,2,3,4-tetrahydroquinoxaline (5), respectively. These compounds are converted to the starting material by autoxidation. The mechanisms of these reduction and reoxidation processes are discussed and proven experimentally. It is shown that 1-methyl-3-oxo-3.4-dihydroquinoxalinium cations (15, 16) are intermediates in the autoxidation process and that the carbonyl oxygen introduced in 2-position is derived from water.
    Notes: Die elektrochemische Reduktion des 1-Methyl- (2) und 1,4-Dimethyl-2,3-dioxo-1,2,3,4-tetra-hydrochinoxalins (3) führt im sauren Medium in einer ungewöhnlichen vierelektronigen Reduktionsstufe zu 1-Methyl- (4) bzw. 1,4-Dimethyl-3-oxo-1,2,3,4-tetrahydrochinoxalin (5), die unter Autoxidation jeweils die Ausgangsverbindungen zurückbilden. Die Mechanismen der Reduktions-und Reoxidationsprozesse werden diskutiert und experimentell belegt. Es wird gezeigt, daß bei der Autoxidation die Stufe eines 1-Methyl-3-oxo-3,4-dihydrochinoxalinium-Kations (15, 16) durchlaufen wird und der eingeführte 2-Carbonylsauerstoff aus dem Wasser stammt.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110510
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    Organische Elektrochemie, II: Synthese und elektrochemisches Verhalten von 6,7-Dioxo-tetrahydropteridinen und 2,3-Dioxotetrahydropyrido-pyrazinen (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1763-1779 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Organic Electrochemistry, II: Synthesis and Electrochemical Behaviour of 6,7-Dioxotetrahydropteridines and 2,3-Dioxotetrahydropyrido-pyrazinesThe 6,7-dioxotetrahydropteridines 1-9 have been synthesized and studied with respect to cathodic electroreduction. The 8-unsubstituted derivatives 1-5 are reduced in acidic as well as basic media in a four electron process to the corresponding 6-oxo-5,6,7,8-tetrahydropteridines (13-17), whereas the reduction of the 8-alkyl derivatives 6-9 stops after a two electron uptake at the 8-alkyl-7-hydroxy-6-oxo-5,6,7,8-tetrahydro level (19-22). The 2,3-dioxotetrahydropyrido-pyrazines 10-12 showed an analogous behaviour with formal reduction of one oxo function to give 23-26 and small amounts of dimeric products (27, 28). The structures of the newly synthesized compounds have been proven by spectroscopic investigations.
    Notes: Die 6,7-Dioxotetrahydropteridine 1-9 warden synthetisiert und der kathodischen Elektro-reduktion unterworfen. Die 8-unsubstituierten Derivate 1-5 werden im allgemeinen sowohl im sauren als auch alkalischen Medium in einem vierelektronigen Prozeß zu den entsprechenden 6-Oxo-5,6,7,8-tetrahydropteridinen (13-17) reduziert, wogegen bei den 8-Alkyl-Derivaten 6-9 die Reduktion nach Aufnahme von 2 Elektronen auf der 8-Alkyl-7-hydroxy-6-oxo-5,6,7,8-tetrahydro-Stufe (19-22) zum Stillstand kommt. Die 2,3-Dioxotetrahydropyrido-pyrazine 10-12 zeigen analoges Reaktionsverhalten unter formaler Reduktion einer Oxo-Funktion zu 23-26 neben der Bildung kleiner Mengen an Dimeren (27, 28). Die Konstitutionen der neu synthetisierten Verbindungen werden durch spektroskopische Untersuchungen gesichert.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19781110511
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    Diazadiphosphetidine durch Cycloaddition von Phosphazenen (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1815-1823 
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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: Diazadiphosphetidines by Cycloaddition of PhosphazenesThe iminophosphoranes 2a-i and 6a-c react with aminodiiminophosphorane 1 to give stable adducts to which we ascribe the cyclic structures 3a-i or 7a,b and 8b,c, resp., on the basis of spectroscopic data and thermal cleavage.
    Notes: Die Iminophosphorane 2a-i und 6a-c bilden mit Aminodiiminophosphoran 1 stabile Addukte, für die aufgrund der spektroskopischen Befunde und der thermolytischen Spaltung die cyclischen Strukturen 3a-i bzw. 7a,b und 8b,c vorgeschlagen werden.
    Additional Material: 3 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19781110515
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    35Cl-NMR-Untersuchungen an Alkyl- und Alkenylchloriden (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1833-1838 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 35Cl NMR Studies on Alkyl and Alkenyl Chlorides35Cl chemical shifts (δ35Cl) are reported for 17 alkyl chlorides and 4 alkenyl chlorides. A linear correlation results between δ35Cl and δ19F of analogous compounds of the type CnH2n+1 X and CnH2nX2. This relationship is not valid if there are more than two halogen atoms bonded to one carbon atom and also in the case of alkenyl halides. The reasons for this are discussed. There is no linear correlation between the calculated charge density on chlorine and δ35Cl.
    Notes: 35)Cl-chemische Verschiebungen (δ35Cl) von 17 Alkylchloriden und 4 Alkenylchloriden werden mitgeteilt. Eine lineare Korrelation zwischen δ35Cl und δ19F analoger Fluoride für Alkylhalogenide des Typs CnH2n+1 X und CnH2nX2 zeigt den gleichsinnigen Einfluß des Alkylrestes auf die chemischen Verschiebungen δ35Cl und δ19 F. Bei mehr als zwei Halogenatomen pro Kohlenstoff versagt diese Beziehung, ebenso bei Alkenylhalogeniden; Gründe hierfür werden diskutiert. Zwischen der berechneten Ladungsdichte am Chlor und δ35Cl läßt sich keine lineare Korrelation herstellen.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19781110517
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    Umlagerungen freier Radikale, 6: Radikale mit Bi-, Tri- und Tetracyclooctan-Gerüst (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 388-399 
    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 Free Radicals, 6: Radicals with Bicyclooctane, Tricyclooctane, and Tetracyclooctane SkeletonRadicals with bicyclo[3.2.1]octane skeleton are generated (2, 11-13) in order to investigate rearrangements to tricyclic (3) and tetracyclic (4) radicals. It is shown by product analysis and by ESR spectroscopy that radicals with bicyclo[3.2.1]octa-2.6-dienyl structure are most stable. This maintains even if substituents which can stabilize structure 4 are introduced in 3-position of 2. Secondary radicals which derive from tricyclo[3.2.1.02,7]oct-3-ene (17), tetracyclo[3.2.1.02,7.04,6]-octane (18), bicyclo[2.2.2]octa-2,5-diene (25) and bicyclo[2.2.2]oct-2-ene (26) also rearrange to 2. Bicyclo[3.2.1]octa-2,6-dienyl radical constitutes the most stable member in this series of radicals.
    Notes: Radikale mit Bicyclo[3.2.1]octan-Gerüst (2, 11-13) werden auf eine Umlagerung in tricyclische (3) und tetracyclische Radikale (4) untersucht. Produktanalysen und ESR-spektroskopische Studien zeigen, daß die Radikale mit Bicyclo[3.2.1]octa-2,6-dienyl-Gerüst am stabilsten sind. Dies trifft auch zu, wenn in 3-Stellung (11-13) von 2 radikalstabilisierende Gruppen eingeführt werden, welche die Konstitution 4, nicht aber 2 stabilisieren können. Auf Grund dieser Ergebnisse ist es nicht überraschend, daß die von Tricyclo[3.2.1.02,7]oct-3-en (17) und Tetracyclo[3.2.1.02,7.04,6]-octan (18) abgeleiteten Radikale sich in das Bicyclo[3.2.1]octa-2,6-dienyl-Radikal 2 umlagern. Gleiches trifft für die aus Bicyclo[2.2.2]octa-2,5-dien (25) und Bicyclo[2.2.2]oct-2-en (26) erzeugten sekundären Radikale 21 und 22 zu.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19781110137
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    Desaminierungsreaktionen, 30: Zerfall von Bicyclo[4.1.0]hept-2-en-7-diazonium-Ionen (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1873-1882 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Deamination Reactions, 30: Decomposition of Bicyclo[4.1.0]hept-2-ene-7-diazonium Ionsexo-Bicyclo[4.1.0]hept-2-ene-7-diazonium ions (16) have been generated from the corresponding nitrosourea 15 and base. In weakly alkaline methanol 7-anti-methoxybicyclo[2.2.1]hept-2-ene (17), 2-exo-methoxybicyclo[3.2.0]hept-6-ene (19), 7-exo-methoxybicyclo[4.1.0]hept-2-ene (20), 5-methoxy-1,3-cycloheptadiene (21), and 3-methoxy-1,4-cycloheptadiene (22) were obtained. 22 is formed by isomerization of 3-methoxy-1(Z),4(E)-cycloheptadiene (30) which was trapped in the presence of furan to give the adducts 25 and 26. 19 is thought to arise by intramolecular cyclization of 5-methoxy-1(Z),3(E)-cycloheptadiene (31). The configurations of 19, 20, 25. and 26 suggest attack of methanol on the partially opened cyclopropyl cation 29. - In CH3OD/HCO2Na all products incorporated approximately the same amount of deuterium. The location of D in 17 indicates that double bond participation in 16 leads immediately to the 7-norbornenyl cation 33, without intervention of the tricyclic cation 32. In the presence of lithium methoxide the products 17 and 18, derived from the 7-norbornenyl cation 33, predominated while 19-22 virtually disappeared. The variation in products is explained in terms of the carbene rearrangement 38 → 41, followed by protonation of 41 to give 33.
    Notes: exo-Bicyclo[4.1.0]hept-2-en-7-diazonium-Ionen (16) wurden durch alkalische Spaltung des entsprechenden Nitrosoharnstoffs 15 erzeugt. In schwach alkalischem Methanol erhielten wir 7-anti-Methoxybicyclo[2.2.1]hept-2-en (17), 2-exo-Methoxybicyclo[3.2.0]hept-6-en (19) 7-exo-Methoxybicyclo[4.1.0]hept-2-en (20), 5-Methoxy-1,3-cycloheptadien (21) und 3-Methoxy-1,4-cycloheptadien (22). 22 wird durch Isomerisierung von 3-Methoxy-1(Z).4(E)-cycloheptadien (30) gebildet, das wir in Form der Furan-Addukte 25 und 26 abfangen konnten. Wir nehmen an, daß 19 aus 5-Methoxy-1(Z),3(E)-cycloheptadien (31) durch intramolekulare Cyclisierung entsteht. Die Konfiguration von 19, 20, 25 und 26 spricht für den Angriff von Methanol auf das „halbgeöffnete“ Cyclopropyl-Kation 29. - Alle in CH3OD/HCO2Na gebildeten Produkte hatten etwa gleichen D-Gehalt. Die Stellung des Deuteriums in 17 zeigt, daß Doppelbindungsbeteiligung von 16 direkt zum 7-Norbornenyl-Kation 33 führt und das tricyclische Kation 32 nicht als Zwischenstufe auftritt. In Gegenwart von Lithiummethylat entstanden überwiegend die Produkte 17 und 18 aus dem 7-Norbornenyl-Kation 33, während 19-22 nun fehlten. Die Änderung der Produktverhältnisse wird durch die Carben-Umlagerung 38 → 41 erklärt, der sich eine Protonierung von 41 zu 33 anschließt.
    Additional Material: 2 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19781110521
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    Desaminierungsreaktionen, 32: Zerfall von Bicyclo[5.1.0]octa-2,4-dien-8-diazonium-Ionen (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1895-1907 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Deamination Reactions, 32: Decomposition of Bicyclo[5.1.0]octa-2,4-diene-8-diazonium Ionsexo-Bicyclo[5.1.0]octa-2,4-diene-8-diazonium ions (11) have been generated from the corresponding nitrosourea (10) and base. In weakly alkaline solution the major products were derivatives of bicyclo[3.3.0]octadiene (12, 13) and 1(Z),3(Z),6(E)-cyclooctatriene (17). The reaction products and the distribution of a deuterium label in 12a, 13a suggest that 11 undergoes conrotatory transformation into the cyclooctatrienyl cation 24 as the first intermediate. In the presence of sodium methoxide, predominant formation of 8-syn-methoxybicyclo[3.2.1]octa-2,6-diene (18a) was observed. 8-Diazo-bicyclo[3.2.1]octa-2,6-diene (39) was generated from the tosylhydrazone 38 and excluded as an intermediate on the reaction path from 11 to 18. Most probably the carbon 1,3-shift proceeds as an interconversion of the carbenes 37 and 40.
    Notes: exo-Bicyclo[5.1.0]octa-2.4-dien-8-diazonium-Ionen (11) wurden durch alkalische Spaltung des entsprechenden Nitrosoharnstoffs (10) erzeugt. In schwach alkalischer Lösung entstanden als Hauptprodukte Derivate des Bicyclo[3.3.0]octadiens (12, 13) und des 1(Z),3(Z),6(E)-Cyclooctatriens (17). Die Reaktionsprodukte und die Verteilung einer D-Markierung in 12a, 13a weisen auf eine conrotatorische Umwandlung von 11 in das Cyclooctatrienyl-Kation 24 als erste Zwischenstufe hin. In Gegenwart von Natriummethylat wurde überwiegend 8-syn-Methoxybicyclo[3.2.1]-octa-2,6-dien (18a) gebildet. 8-Diazobicyclo[3.2.1]octa-2,6-dien (39) wurde aus dem Tosylhydrazon 38 erzeugt und als Zwischenstufe auf dem Weg von 11 zu 18 ausgeschlossen. Sehr wahrscheinlich erfolgt die 1,3-Kohlenstoffverschiebung als Umlagerung des Carbens 37 in 40.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19781110523
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    Addition von Aldehyden an aktivierte Doppelbindungen, XVI: Darstellung von Diketocarbonsäureestern (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 431-438 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Addition of Aldehydes to Activated Double Bonds, XVI: Preparation of Esters of Dioxocarboxylic AcidsThiazolium salt catalysed addition of aldehydes to vinyl oxe-esters and of ester-aldehydes to vinyl ketones leads to esters of dioxocarboxylic acids.
    Notes: Unter Thiazoliumsalz-Katalyse werden Aldehyde an Vinylketoester und Esteraldehyde an Vinylketone unter Bildung von Diketocarbonsäureestern addiert.
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    URL: http://dx.doi.org/10.1002/cber.19781110203
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