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  • Articles: DFG German National Licenses  (1,408)
  • 1975-1979  (1,408)
  • 1965-1969
  • 1920-1924
  • 1840-1849
  • 1978  (1,408)
  • Inorganic Chemistry  (765)
  • Life and Medical Sciences  (625)
  • Bone
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  • Articles: DFG German National Licenses  (1,408)
Material
Years
  • 1975-1979  (1,408)
  • 1965-1969
  • 1920-1924
  • 1840-1849
Year
Keywords
  • 1
    Electronic Resource
    Electronic Resource
    Scanning electron microscope study of separated calcospherites from the matrices of different mineralizing systems (1978)
    Springer
    Calcified tissue international 26 (1978), S. 47-49 
    Details
    ISSN: 1432-0827
    Keywords: Matrix vesicles ; Calcospherites ; Mineralization ; Bone ; Dentin ; Cartilage ; SEM
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Mineral particle cluster, corresponding to calcospherites or matrix vesicle-initiated clusters in calcifying cartilage and dentin and to collagen bundle-related mineralization in lamellar bone, have been isolated from NaOCl solutions used to dissolve the organic matrix in preparation of anorganic mineralizing fronts for scanning electron microscopy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02013233
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  • 2
    Electronic Resource
    Electronic Resource
    Mechanism of osteoclastic bone resorption: A new hypothesis (1978)
    Springer
    Calcified tissue international 26 (1978), S. 81-84 
    Details
    ISSN: 1432-0827
    Keywords: Osteoclasts ; Bone ; Resorption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Osteoclastic bone resorption involves the solubilization of the mineral salts and the degradation of noncollagen bone matrix and collagen fibrils. As no recognizable collagen fibrils have ever been reported within cytoplasmic vacuoles in osteoclasts, it is generally assumed that the collagen fibrils are digested extracellularly in the resorption zone. The extent to which lysis occurs extracellularly and whether or not the osteoclasts phagocytose the degradation products remain to be established. In the present communication, a hypothesis is presented suggesting the possibility that osteoclastic resorption of bone involves the participation of two different cell types. According to this hypothesis, osteoclastic bone resorption is initiated by osteoclasts that demineralize areas of bone and degrade noncollagen bone matrix. After the osteoclasts have moved away or become partially detached from the demineralized site, the exposed collagen fibrils are phagocytosed by mononuclear, fibroblast-like or monocyte-derived cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02013238
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  • 3
    Electronic Resource
    Electronic Resource
    Plasma disappearance of rabbit α2 HS-glycoprotein and its uptake by bone tissue (1978)
    Springer
    Calcified tissue international 26 (1978), S. 155-161 
    Details
    ISSN: 1432-0827
    Keywords: Plasma protein ; Glycoprotein ; Bone ; Glucosamine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Plasmaα 2HS-glycoprotein is specifically accumulated in calcified tissues. In the present studies this glycoprotein was isolated from plasma and after iodination with iodine-125 was injected intravenously into young rabbits. The tissue distribution and plasma disappearance rate of this radioactively labeled material were determined. Of the various tissues studied, bone showed the greatest retention of labeled glycoprotein expressed as percentage of the injected dose per gram tissue relative to the plasma content. The rate of loss of iodinatedα 2HS-glycoprotein from plasma was similar to that ofα 2HS-glycoprotein labeled endogenously by using14C-glucosamine or3H-glucosamine. The uptake of exogenously labeled3I-α 2HS-glycoprotein into bone tissue expressed as a percentage of the injected dose was similar to that of endogenously labeled14C-α 2HS-glycoprotein. These results suggest that the125I-labeled material can be used to study further the metabolism ofα 2HS-glycoprotein by bone tissue.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02013251
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  • 4
    Electronic Resource
    Electronic Resource
    Effect of mithramycin on boneβ-glucuronidase and resorption (1978)
    Springer
    Calcified tissue international 26 (1978), S. 209-213 
    Details
    ISSN: 1432-0827
    Keywords: Mithramycin ; Bone ; β-Glucuronidase ; KT medium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Mithramycin suppresses bone resorption. Its effect on the synthesis and release of β-glucuronidase (a referent for lysosomal enzymes) in mouse calvarial explants was studied in an in vitro culture system. A newly described medium (designated as KT medium) was introduced in this specific study. Mithramycin initially inhibited the release of β-glucuronidase into the medium and resulted in an ultimate accumulation of this enzyme in the bone. These results suggest that inhibition of bone resorption by mithramycin may be attributed to interference in release of lysosomal enzymes from bone cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02013260
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  • 5
    Electronic Resource
    Electronic Resource
    A rare clinical presentation of blastomycosis (1978)
    Springer
    Skeletal radiology 2 (1978), S. 239-242 
    Details
    ISSN: 1432-2161
    Keywords: Blastomycosis ; Bone ; Pulmonary ; Skin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract North American blastomycosis is a multisystem disease, primarily affecting the lungs and skin. The skeleton is affected in approximately 50% of cases. Bone symptoms as the primary clinical complaint are exceedingly rare. Two such cases are presented together with a brief discussion of this rare disease.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00347400
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  • 6
    Electronic Resource
    Electronic Resource
    Effect of chronic centrifugation on bone density of the dog (1978)
    Springer
    Anatomy and embryology 153 (1978), S. 321-329 
    Details
    ISSN: 1432-0568
    Keywords: Bone ; Femur ; Density ; Hypergravity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Sixteen male Beagle dogs, 293 to 509 days old, were exposed almost continuously for 3 months to 2.0 G on a 7.9 m radius centrifuge. The dogs were maintained on the centrifuge by means of a specially designed, automated waste disposal and life support system. Bone density was measured by a 125I Profile Scanner in the anterior, medial, posterior and lateral cortex of the femoral mid-shaft. As compared to mean density in the femora of normal gravity controls, centrifuged dogs showed a 0.8% (P〈0.05) lower mean linear absorption in their femora. However, the regression of density on the square-root of cross-sectional area/π differs very significantly in the animals living at earth gravity and those living at hypergravity. Thin hypergravic bones are denser, thick hypergravic ones are less dense than the corresponding ones of normal gravity controls.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00315934
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  • 7
    Electronic Resource
    Electronic Resource
    Radiogenic free radicals as molecular probes in bone (1978)
    Springer
    Calcified tissue international 25 (1978), S. 37-43 
    Details
    ISSN: 1432-0827
    Keywords: ESR ; Radiation free radicals ; CO3-Apatites ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Exposure of bone mineral to X-rays generates free radicals. These are usually very labile, but can be stabilized at liquid nitrogen temperatures for study by electron spin resonance spectroscopy. The free radicals thus detected in the present study included one with resonances arising from an electron excess center and 2 species with electron-deficit centers: a phosphate anion radical and a radical associated with carbonate. Each of these radicals seemed to be located chiefly at the mineral surface and was sensitive to the surface environment. Presence of an organic phase, as in whole bone, modified free radical production in a manner that suggests interference with the formation of electron deficit centers. Comparison with other synthetic minerals suggests that precipitated carbonateapatites are good models for bone mineral.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02010749
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  • 8
    Electronic Resource
    Electronic Resource
    Selective stimulation of net calcium efflux from chick embryo tibiae by parathyroid hormone in vitro (1978)
    Springer
    Calcified tissue international 25 (1978), S. 227-232 
    Details
    ISSN: 1432-0827
    Keywords: Parathyroid hormone ; Bone ; Calcium ; Chick embryo ; Organ culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The purpose of this study was to measure in an in vitro system the movement of Ca and phosphate (Pi) out of bone when treated with parathyroid hormone (PTH). Tibiae from 13-day chick embryos were incubated for up to 8 h in a defined medium containing 1.8 mM Ca. Medium samples were collected every 2 h and were analyzed for Ca, Pi and lactate. Net effluxes from the bones were calculated. When bones were incubated with PTH in the medium (1 U/ml), net Ca efflux was increased 44, 60 and 100% at 4, 6 and 8 h, respectively. At no time was net Pi efflux affected by the hormone. The well known PTH-stimulated lactate production was not seen until 8 h. Lower doses of PTH (0.1 and 0.3 U/ml) were also effective. Comparing PTH (1 U/ml) responsiveness at higher (2.2 mM) and lower (0.9 mM) medium Ca concentrations, showed that with 2.2 mM Ca no increased Ca efflux was seen, while with 0.9 mM Ca significant elevation in medium Ca occurred 2 h sooner than in the experiments using 1.8 mM Ca. In another experiment, varying the medium Pi level from 1 to 2 mM had no effect on the Ca response to PTH. In neither experiment was Pi release affected by PTH. The results of this study have led to the following conclusions: (1) PTH acts on bone to cause an early dose related increase in net Ca efflux; (2) the effect is specific for Ca, since it is not accompanied by an increased Pi efflux, and may be saturated by raising the medium Ca level; and (3) PTH-stimulated Ca efflux in this system is not correlated with, and is probably not a result of increased lactate production.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02010774
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  • 9
    Electronic Resource
    Electronic Resource
    A bone resorbing substance from bovine serum albumin (brA) (1978)
    Springer
    Calcified tissue international 25 (1978), S. 233-240 
    Details
    ISSN: 1432-0827
    Keywords: Bone ; Bone resorption ; Albumin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary A fraction (brA), which causes resorption of fetal rat bones in vitro, has been concentrated from bovine serum albumin by anion exchange column chromatography on DEAE Sephadex. This active fraction has also been prepared using DEAE Sephadex A-50 by a batch method with a 0.09M NaCl, 0.1M TRIS buffer, pH 8.35. BrA was 10–30 times more potent than the original albumin. The retained material, which constitutes the bulk of the protein and has less activity than the original albumin, elutes with 0.45M NaCl. Similar treatment of serumα,β or γ globulins does not yield brA. Further enhancement of the bone resorbing activity of brA can be obtained with (NH4)2SO4 fractionation or extraction with CH3OH∶CHCl3. Heating at 55° C for 2 h or at 100° C for 10 min does not affect the activity; overnight incubation with protease destroys the bone resorbing effect. The bone resorbing activity is not removed by dialysis and does not correlate with the protease activity of the fraction. The action of brA is inhibited by 3 mM PO4, 1 μg/ml calcitonin or glucagon, 10−7 M dexamethasone or 0.02 μg/ml actinomycin D. The bone resorbing activity of brA is partially inhibited by 10−7–10−5 M indomethacin. PTH did not elicit bone resorption when added to cultures incubated in chemically defined medium supplemented with 0.1 mg/ml brA. However, brA did not inhibit PTH-induced resorption.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02010775
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  • 10
    Electronic Resource
    Electronic Resource
    Oestrogen binding proteins in bone cell cytosol (1978)
    Springer
    Calcified tissue international 25 (1978), S. 249-254 
    Details
    ISSN: 1432-0827
    Keywords: Bone ; Oestrogens ; Oestrogen receptors ; Binding proteins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Attempts were made to demonstrate the presence of specific oestrogen binding proteins (“receptors”) in bone cells. High speed cytosol preparations of bone were incubated with several concentrations of radioactive oestradiol alone and with radioactive oestradiol in the presence of a specific antioestrogen, Nafoxidine. Separation of bound and free oestradiol was carried out by dextran coated charcoal treatment and by sucrose gradient ultracentrifugation. Several types of bones likely to be oestrogen-sensitive were investigated: human femoral heads, human phalanx, rat and rabbit calvaria, humeri and femora of female rats. In all experiments we were unable to demonstrate the presence of specific oestrogen receptors in bone cell cytosol indicating that the direct effect of oestrogens on bone, if present, is not mediated by specific oestrogen receptors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02010778
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  • 11
    Electronic Resource
    Electronic Resource
    Quantitative histology of bone: A computerized method of measuring the total mineral content of bone (1978)
    Springer
    Calcified tissue international 26 (1978), S. 85-89 
    Details
    ISSN: 1432-0827
    Keywords: Bone ; Histology ; Microradiography ; Densitometry ; Computer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary A comparatively simple quantitative method for assessing bone morphology has been evolved. Microradiographs of thin sections of mandible have been scanned with a Joyce-Loebl double beam recording microdensitometer with a scanning autodensidater attachment, using a white beam. For each image the optical densities for all the pixels (picture elements) were divided into 10 groups. The limits of the division were fixed by the maximum and minimum densities occurring within the image. A computer generated map was produced which indicated the spatial distribution of the pixels within each group to which an arbitrarily chosen shading was attached. The number of pixels within each group is also shown on the map. The computer map was compared with the photomicrograph and, where necessary, the original section. The fractional area of hard tissue was then readily determined using the numerical values of each group of pixels.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02013239
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  • 12
    Electronic Resource
    Electronic Resource
    Surface area of dental enamel, bone, and hydroxyapatite: Chemisorption from solution (1978)
    Springer
    Calcified tissue international 26 (1978), S. 139-142 
    Details
    ISSN: 1432-0827
    Keywords: Chemisorption ; Surface area ; Hydroxyapatite ; Bone ; Enamel
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The surface areas of three different samples of hydroxyapatite, samples of deproteinized bone, and samples of whole and deproteinized enamel were determined by adsorption of an adduct (the diglycidyl ether of bisphenol A with N-phenylglycine) from methylene chloride solution. In all cases, the surface areas of these samples agree well with those obtained by the BET (N2) method.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02013248
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  • 13
    Electronic Resource
    Electronic Resource
    Effect of sex steroids on bone collagen synthesis in vitro (1978)
    Springer
    Calcified tissue international 25 (1978), S. 105-110 
    Details
    ISSN: 1432-0827
    Keywords: Progesterone ; 17β estradiol ; Testosterone ; Tissue culture ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Although sex steroids are known to affect skeletal metabolism, their effects on bone collagen synthesis have not been studied. We have examined the direct effects of progesterone, 17β estradiol, testosterone, 5α dihydrotestosterone and dehydroepiandrosterone on bone collagen and noncollagen protein synthesis in cultures of calvaria obtained from 21-day fetal rats. Bones were incubated for 24 to 168 h and3H-proline was added for the last 2 h of culture. Incorporation of the label into collagenase-digestible protein (CDP)1 and noncollagen protein (NCP) was determined using repurified bacterial collagenase. Progesterone caused a dose dependent inhibition of the labeling of CDP at concentrations of 3×10−7 M to 10−5 M after 96 h of culture. A smaller inhibitory effect was observed on NCP. The inhibitory effect was slow in onset and persisted when bones were incubated for 48 h with progesterone and then transferred to control medium for 48 h. Progesterone also inhibited the incorporation of3H-thymidine and3H-uridine into fetal rat calvaria. After 24 h of culture, 17β estradiol and testosterone had no effects on the labeling of CDP and NCP. After 96 h, 17β estradiol had a small and inconsistent stimulatory effect on the labeling of CDP but testosterone had no effect. Neither hormone altered the inhibitory effects of parathyroid hormone, cortisol and progesterone. Dihydrotestosterone and dehydroepiandrosterone had no effects after 24 h and 96 h of culture. 17β estradiol, testosterone and dihydrotestosterone did not affect the incorporation of3H-uridine or3H-thymidine into fetal rat calvaria. Our studies indicate that progesterone is an inhibitor of bone collagen synthesis and estrogens and androgens are not major regulators of bone formation in vitro.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02010758
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  • 14
    Electronic Resource
    Electronic Resource
    The effect of growth retardation and of osteomalacia on the uptake of albumin by bone (1978)
    Springer
    Calcified tissue international 25 (1978), S. 29-35 
    Details
    ISSN: 1432-0827
    Keywords: Albumin ; Bone ; Growth retardation ; Osteomalacia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary 125I-labeled rat albumin injected intravenously into rats was taken up by growing bone. Some of this radioactive albumin could be removed from bone by washing with saline, the proportion so removed decreasing from 82.5% at 1 day to 7.4% at 8 days. Both the total radioactivity, and that remaining in bone after saline wash, were reduced when growth was slowed by alteration or restriction of the diet. Although the amount of125I albumin in rachitic bone was reduced, autoradiography showed that radioactivity was present in rachitic osteoid. Immunoprecipitation using anti-rat-albumin serum showed that about half of the radioactivity released from normal bone by EDTA was still attached to albumin. These results suggest that albumin plays some part in the growth of bone.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02010748
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  • 15
    Electronic Resource
    Electronic Resource
    Diabetische Osteomyelopathie: histobioptische Befunde am Knochen und Knochenmark bei Diabetes mellitus (1978)
    Springer
    Journal of molecular medicine 56 (1978), S. 743-754 
    Details
    ISSN: 1432-1440
    Keywords: Bone ; Bone marrow ; Bone marrow biopsy ; Immunhistology ; Diabetes mellitus ; Diabetic microangiopathy ; Diabetic osteomyelopathy ; Knochen ; Knochenmark ; Myelotomie ; Immunhistologie ; Diabetes mellitus ; Diabetische Mikroangiopathie ; Diabetische Osteomyelopathie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Beckenkammbiopsien von 118 Patienten mit manifestem Diabetes mellitus wurden histologisch und histomorphometrisch ausgewertet und mit den klinischen Daten verglichen. Die histobioptischen Ergebnisse zeigen, daß sich die „diabetische Mikroangiopathie“ auch im Gefäßsystem des Knochenmarkes manifestiert. Mit Betonung im Bereich der Arteriolen und Kapillaren waren einerseits exsudativ-degenerative Wandveränderungen, andererseits entzündlich-fibrosierende perivaskuläre Reaktionen nachweisbar. Pathogenetisch sind diese Gefäßveränderungen bei Diabetes mellitus im Rahmen einer biochemisch veränderten Basalmembran mit erhöhter Permeabilität für Plasmaproteine zu erklären, die wiederum eine perivaskuläre Entzündungsreaktion auslösen. Neben der angiologischen Beurteilung des Diabetikers ermöglicht die Beckenkammbiopsie auch differenzierte und quantifizierbare Aussagen über hämatologische und osteologische Probleme im Rahmen des diabetischen Spätsyndroms. Bisher unbekannt war bei Diabetes mellitus die ausgeprägte Entzündungsreaktion des Knochenmarkstromas, die mit den serologischen Entzündungsparametern korreliert und sich klinisch häufig als sog. Infektanämie äußert. Eine Beteiligung der beschriebenen Myelitis an der Pathogenese des markatrophisch-osteoporotischen Bildes bei Diabetes mellitus kann angenommen werden. Knochenveränderungen bei Diabetes mellitus treten gegenüber einem altersentsprechenden Normalkollektiv signifikant häufiger auf und manifestieren sich als rarefizierende Osteopathie ohne wesentliche Umbausteigerung. Als Ursache kommen neben der dia betischen Mikroangiopathie mit begleitender Myelitis zahlreiche andere Faktoren, wie Störung der Kollagensynthese, des Kalziumstoffwechsels sowie Bewegungsmangel in Frage. Übereinstimmend mit den Ergebnissen anderer Autoren wiesen die Patienten mit Insulin-Therapie gegenüber oral eingestellten Diabetikern einen geringeren Osteoporosegrad auf. Unsere Ergebnisse erlauben die morphologische und klinische Definition einer diabetischen Osteomyelopathie mit eigenständiger Pathogenese. Sie ist charakterisiert durch 1. exsudativ-entzündliche Veränderungen der Knochenmarkgefäße, 2. plasmazelluläre Myelitis mit markatrophischer Komponente, 3. Osteoporose ohne nachweisbare Umbausteigerung.
    Notes: Summary Iliac crest biopsies from 118 patients with manifest diabetes were evaluated histologically and histomorphometrically and compared with the clinical data. The histobioptic results show that “diabetic microangiopathy” is also manifest in the vascular system of the bone marrow. Exudative degenerative changes in the vessel wall on the one hand, and inflammatory fibrosing perivascular reactions on the other were accentuated in the region of the arterioles and capillaries. These vascular changes in diabetes mellitus can be attributed to a biochemically altered basal membrane with increased permeability for plasma protein which, in turn, set up a perivascular inflammatory reaction. In addition to the angiological assessment of diabetics, iliac crest biopsy also permits differentiated and quantifiable statements on the haematological and osteological problems involved in the late diabetic syndrome. The marked inflammatory reaction of the bone marrow stroma was previously unknown in diabetes mellitus; it correlates with the serological inflammatory parameters and frequently becomes manifest as “anemia of chronic disorders”. It can be assumed that this reaction also takes part in the pathogenesis of the atrophy of the bone marrow and osteoporosis in diabetes mellitus. Bone changes in the form of atrophic osteopathy without essentially increased bone remodeling are to be found more frequently in diabetes mellitus than in a normal collective of similar age. In addition to diabetic microangiopathy with concomitant inflammation, numerous other causes such as disturbances of collagen synthesis, of calcium metabolism and lack of movement are to be considered. In accordance with other authors, the patients on insulin therapy showed a smaller degree of osteoporosis than orally adjusted diabetics. For these pathogenetic reasons, a specific diabetic osteomyelopathy can be established. It is characterised by: 1. exudative inflammatory changes of the bone marrow vessels, 2. plasmocytic marrow reactions and parenchymal reduction 3. osteoporosis without signs of increased remodeling of the bone.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01476763
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  • 16
    Electronic Resource
    Electronic Resource
    The reaction of different skeletal sites to metabolic bone disease — A micromorphometric study (1978)
    Springer
    Journal of molecular medicine 56 (1978), S. 755-759 
    Details
    ISSN: 1432-1440
    Keywords: Knochenhistologie urämischer Osteopathie ; Calciumstoffwechsel ; metabolische Knochenerkrankungen ; Mikromorphometrie ; Bone ; Metabolic Bone Disease ; Uremic Osteodystrophy ; Calcium Metabolism ; Malignant Tumors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary It is unknown whether histomorphometric parameters of bone surface remodelling change uniformly throughout the skeleton in metabolic bone disease. In patients without skeletal disease (n=8), in patients with chronic renal failure (n=13) and in patients with malignant tumors (n=11), post mortem bone samples were taken from the core of the 5th lumbar vertebra, from the iliac crest, from the femural head and from the interepicondylar portion of the distal femur. Histomorphometric analysis was carried out in undecalcified sections stained after Masson-Goldner. The dispersion of histomorphometric parameters between the different skeletal sites (cancellous bone) was evaluated by analysis of variance. There existed marked differences in the surface extension of the histomorphometric parameters which are related to bone remodelling, suggesting marked differences in the local remodelling rates (iliac crest 〉 lumbar vertebra 〉 femural head 〉 distal femur). In patients with bone disease all histomorphometric parameters changed uniformly throughout the skeleton with the exception of inactive osteoid. The study shows that in metabolic bone disease local factors do not interfere with remodelling in response to systemic factors. It also provides evidence that bone biopsy samples from iliac crest spongiosa reflect with reasonable accuracy the changes occurring elsewhere in the skeleton, although inactive osteoid may accumulate in the iliac crest out of proportion to its increase in low-turnover sites.
    Notes: Zusammenfassung Bei skelettgesunden Kontrollpersonen (n=8), bei Patienten mit chronischer Niereninsuffizienz (n=13) und bei Patienten mit malignen Tumoren (n=11) wurden post mortem Knochenbiopsie-Proben aus dem 5. Lendenwirbelkörper, aus dem Bekkenkamm, aus dem Femurkopf und aus dem interepikondylären Teil des distalen Femur entnommen. Unentkalkte, nach Masson-Goldner gefärbte Dünnschnitte wurden histomorphometrisch untersucht. Die Varianz einzelner histomorphometrischer Parameter zwischen den unterschiedlichen Skelettorten wurde durch Varianzanalyse überprüft. Die histomorphometrischen Parameter, welche in Beziehung zum inneren Knochenumbau stehen, waren in den einzelnen Skelettorten außerordentlich unterschiedlich. Die lokalen Umbauraten differieren daher wahrscheinlich stark (Beckenkamm 〉 Lendenwirbelkörper 〉 Femurkopf 〉 distaler Femur). Bei Patienten mit Knochenerkrankungen änderten sich alle histomorphometrischen Parameter gleichsinnig an allen untersuchten Skelettorten. Lediglich die Volumendichte und die Oberflächendichte inaktiven Osteoids zeigte in den einzelnen Skelettorten ein signifikant unterschiedliches Verhalten. Die Untersuchung belegt, daß bei systemischen Knochenerkrankungen lokale Faktoren nicht die Antwort des Skeletts auf systemische Stimuli beeinträchtigen. Die Messergebnisse belegen, daß Knochenbiopsie-Proben aus der Beckenkammspongiosa mit hinreichender Genauigkeit die Vorgänge widerspiegeln, die in anderen Skelettorten ablaufen. Lediglich für inaktives Osteoid konnte bei urämischen Patienten gezeigt werden, daß in der Beckenkammspongiosa eine — im Vergleich zu Skelettorten mit niedrigerer Umbaugeschwindigkeit — überproportioniert starke Akumulation stattfindet.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01476764
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  • 17
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    Electronic Resource
    Chondrosarcoma (1978)
    Springer
    International orthopaedics 2 (1978), S. 333-341 
    Details
    ISSN: 1432-5195
    Keywords: Bone ; Neoplasm ; Chondrosarcoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé 163 cas de chondrosarcome repertoriés dans le Swedish Cancer Registry entre 1958 et 1968 ont été soumis à une analyse multifactorielle. 25, 38 et 35% étaient respectivement, fortement, modérément, et faiblement différenciés, et 2% étaient du type mésenchymateux. Les formes modérément et faiblement différenciées montraient habituellement une anaplasie généralisée, des noyaux multiples et souvent pâles, des nucléoles distincts, des images de mitoses et parfois des foyers de cellules fusiformes. Le degré de cellularité n'était pas en rapport avec la différenciation. Le pronostic dépend de la taille de la tumeur, de l'importance de sa vascularisation ainsi que de son stade histologique. Le siège de la tumeur est un élément primordial pour décider de l'importance de l'exérèse chirurgicale. La survie est liée à l'ablation primitive et radicale de la tumeur, par résection ou amputation. Indépendamment des particularités cliniques ou de celles de la tumeur, le meilleur traitement dans chaque cas consiste dans l'exérèse complète de la tumeur, en préservant la fonction dans la mesure du possible.
    Notes: Summary All cases of unequivocal chondrosarcoma recorded in the Swedish Cancer Registry for the years 1958 to 1968 were subjected to a multifactorial analysis. Of a total of 163 chondrosarcomas 25, 38 and 35% respectively were well, moderately and poorly differentiated, and 2% were of mesenchymal type. The moderately and poorly differentiated tumours characteristically exhibited general anaplasia, multiple often pale nuclei, distinct nucleoli, mitotic figures and occasionally spindle cell foci. The degree of cellularity was not of decisive value in differentiation. The prognosis was influenced by the extent and degree of vascularisation of the tumour and by the histopathological grading. The localisation of the tumour was of major importance in deciding the extent of operative treatment and prognosis. Primary radical removalen bloc by resection or ablative surgery was decisive for survival. Irrespective of the clinical and tumour variations, optimum treatment in individual cases involves complete removal of the tumour and, as far as possible, preservation of function.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00571818
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  • 18
    Electronic Resource
    Electronic Resource
    Cell mediated immunity to allografts of fresh and treated bone (1978)
    Springer
    International orthopaedics 2 (1978), S. 171-175 
    Details
    ISSN: 1432-5195
    Keywords: Bone ; Allograft
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé Les auteurs ont étudié chez des rats consanguins la capacité des greffes osseuses fraîches ou conservées à provoquer des réponses immunes cellulaires. Cette réaction a été estimée grâce au test du rejet accéléré et au test de migration des leucocytes. Le premier, bien que relativement imprécis, a mis en évidence une sensibilisation chez la plupart des receveurs de ces greffes fraîches ou congelées. L'importance de cette sensibilisation est fonction des souches de rats utilisées. La plupart des receveurs n'ont pas été sensibilisés par l'os lyophilisé. Par contre, le test de nigration des leucocytes a nettement montre que des greffes d'os frais, spongieux ou cortical, ainsi que celles d'os congelé, sensibilisent les receveurs, L'os lyophilisé n'a sensibilisé que 30% des receveurs. La suppression des cellules de la moëlle de ces greffes n'empêche pas le déclenchement de l'immunité cellulaire. Les auteurs discutent la signification de ces constatations.
    Notes: Summary The ability of fresh and preserved bone grafts to evoke cell mediated immune responses has been studied in inbred rats. The second set skin graft assay and leucocyte migration (LM) test have been used for this purpose. The former test proved to be rather insensitive but indicated sensitisation in most recipients of fresh and frozen bone grafts. The degree of sensitisation was dependent upon the strain combination used. Freeze-dried bone did not sensitise the majority of recipients. The leucocyte migration assay showed clearly that grafts of fresh cancellous or cortical bone, or frozen bone do sensitise the host. Freeze-dried bone sensitised only 30% of recipients. It was also found that removal of bone marrow cells from the grafts did not impair immunogenicity with respect to cell mediated immunity. The implications of these findings are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00265761
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  • 19
    Electronic Resource
    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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  • 20
    Electronic Resource
    Electronic Resource
    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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  • 21
    Electronic Resource
    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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  • 22
    Electronic Resource
    Electronic Resource
    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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  • 23
    Electronic Resource
    Electronic Resource
    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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  • 24
    Electronic Resource
    Electronic Resource
    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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  • 25
    Electronic Resource
    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.19781110401
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  • 26
    Electronic Resource
    Electronic Resource
    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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  • 27
    Electronic Resource
    Electronic Resource
    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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  • 28
    Electronic Resource
    Electronic Resource
    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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  • 29
    Electronic Resource
    Electronic Resource
    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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  • 30
    Electronic Resource
    Electronic Resource
    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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  • 31
    Electronic Resource
    Electronic Resource
    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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  • 32
    Electronic Resource
    Electronic Resource
    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.
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    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.
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    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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  • 35
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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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  • 36
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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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  • 37
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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 
    Details
    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.
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    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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    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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    Chlorierung von N-substituierten Carbonsäureamiden (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1619-1626 
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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: 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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    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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  • 46
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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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    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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  • 48
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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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  • 49
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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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  • 50
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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.
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    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.
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    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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    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.
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    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.
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    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 
    Details
    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.
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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.
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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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    Photochemisch ausgelöste Additionen organischer Disulfide an die Zentralbindung eines Bicyclo[1.1.0]butans (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1938-1943 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photochemically Induced Additions of Organic Disulfides to the Central Bond of a Bicyclo[1.1.0]butaneThe irradiation of an equimolar solution of an organic disulfide (5a-d) and of tricyclo[4.1.0.02,7]-heptane (4) yielded as the main product a stereoisomeric mixture of the bis-thioethers 7 and 8, accompanied by some sulfide 6. The latter compound was formed nearly exclusively if bulky substituents were fixed to the disulfide (5e,f).
    Notes: Die Bestrahlung einer äquimolaren Lösung eines organischen Disulfids (5a-d) und von Tricyclo-[4.1.0.02,7]heptan (4) lieferte als Hauptprodukt ein Stereoisomerengemisch der Bis-thioether 7 und 8, daneben in geringerer Ausbeute das Sulfid 6. Letzteres entstand nahezu ausschließlich, wenn am Disulfid sperrige Reste hafteten (5e,f).
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    URL: http://dx.doi.org/10.1002/cber.19781110527
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    Photoelektronenspektren und MNDO-Rechnungen für [n]Paracyclophane (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1958-1961 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photoelectron Spectra and MNDO-Calculations for [n]ParacyclophanesThe observed splittings of the first two photoelectron bands and the calculated strain energies of the [n]paracyclophanes are discussed; a simple model suggests that they are mainly due to the deformation of the benzene ring. Energetic considerations lead to the conclusion that the “aromatic character” of the benzene moiety in the [n]paracyclophanes has been lost to a large extent for n = 6, and completely for n = 5.
    Notes: Die beobachteten Aufspaltungen der beiden ersten Photoelektronenbanden und die berechneten Spannungsenergien der [n]Paracyclophane werden diskutiert und in einem einfachen Modell vorwiegend auf die Deformation des Benzolrings zurückgeführt. Energetische Überlegungen führen zu dem Schluß, daß der „aromatische Charakter“ der Benzoleinheit in den [n]Paracyclophanen bei n = 6 weitgehend und bei = 5 vollständig verlorengegangen ist.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19781110529
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  • 64
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    Dreikernige Sandwichkomplexe mit Dialkylphosphonat-Brückenliganden: Synthese, NMR-, IR- und Raman-spektroskopische Untersuchungen (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 451-468 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Trinuclear Sandwich Compounds Containing Dialkylphosphonate as Bridging Ligands: Synthesis, NMR-, IR-, and Raman StudiesThe solvolysis of [C5H5Co{P(OR)2O}3BF]BF4 (3) leads to the half-sandwich complex [C5H5Co{P(O)(OR)2}2{P(OH)(OR)2}] (4). 4 is a novel O3-tripod ligand which reacts with the bivalent metalions M = Mg, Ca, Sr, Ba, Pb, Mn, Fe, Co, Ni, Cu, Zn, Cd, Hg to give the trinuclear compounds [{(C5H5)Co[P(O)(OR)2]2}2M] (5a-m). In these sandwich like complexes the dialkylphosphonate ligands are forming bridges of the type Co—(P—O)3—M—(O—P)3—Co between the three metal centers. The 1H NMR spectra are discussed. Due to a non-regular octahedral coordination of the central ion M = Cu and Hg the vP = O and δP = O bands in the IR spectra of 5j and 5m are split. It is shown by means of the IR spectra that the Jahn-Teller distorted octahedral coordination of CuII in 5j is changed to a regular one under the influence of high pressure (35 kbar).
    Notes: Es wird über die Synthese des Halbsandwichkomplexes [C5H5Co{P(O)(OR)2}2{P(OH)(OR)2}] (4) aus [C5H5Co{P(OR)2O}3BF]BF4 (3) berichtet. 4 ist ein neuartiger O3-Tripodligand, der mit den zweiwertigen Metall-Ionen M = Mg, Ca, Sr, Ba, Pb, Mn, Fe, Co, Ni, Cu, Zn, Cd, Hg zu dreikernigen Verbindungen der Zusammensetzung [{(C5H5)Co[P(O)(OR)2]3}2M] (5a-m) reagiert. In den sandwich-artigen Komplexen 5 bilden die Dialkylphosphonatliganden Brücken der Art Co—(P—O)3—M—(O—P)3—Co zwischen den drei Metallzentren. Die 1H-NMR-Spektren werden diskutiert. Im IR-Spektrum beobachtet man als Folge der nicht regulären Oktaederkoordination beim CuII-Komplex 5j und bei der Quecksilberverbindung 5m eine Aufspaltung der VP = O und δP = O-Banden. An Hand der IR-Spektren wird gezeigt, daß die Jahn-Teller-Verzerrung des CuII-Komplexes 5j unter einem Druck von 35 kbar aufgehoben werden kann.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19781110205
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    Ringverengung von 5,6-Dihydro-2H-1,2,3,6-thiatriazin-1-oxiden zu Derivaten des Δ3-1,2,3-Thiadiazolins; Röntgenstrukturanalyse von 2,4-Dimethyl-5-tosylimino-Δ3-1,2,3-thiadiazolin (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1989-1997 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Ring Contraction of 5,6-Dihydro-2H-1,2,3,6-thiatriazine 1-Oxides into Δ3-1,2,3-Thiadiazoline Derivatives; X-Ray Analysis of 2,4-Dimethyl-5-tosylimino-Δ3-1,2,3-thiadiazoline5,6-Dihydro-2H-1,2,3,6-thiatriazine 1-oxides 1a-d rearrange in the presence of trifluoroacetic acid to give 2,4,5,6,7,7a-hexahydro-1,2,3-benzothiadiazole 1-oxides 2a, b and Δ3-1,2,3-thiadiazoline 1-oxides 2c, d, respectively. On treatment with trifluoroacetic acid, at C-5 unsubstituted 5,6-dihydro-2H-1,2,3,6-thiatriazine 1-oxides 1e and f, however, yield Δ3-1,2,3-thiadiazolines 4e and f, respectively, by loss of H2O. Two reaction pathways are suggested for the formation of the ring contraction products. The structure of 4e was confirmed by X-ray analysis.
    Notes: Die 5,6-Dihydro-2H-1,2,3,6-thiatriazin-1-oxide 1a-d lagern in Gegenwart von Trifluoressigsäure in die 2,4,5,6,7,7a-Hexahydro-1,2,3-benzothiadiazol-1-oxide 2a, b bzw. in die Δ3-1,2,3-Thiadiazolin-1-oxide 2c, d um. Die an C-5 unsubstituierten 5,6-Dihydro-2H-1,2,3,6-thiatriazin-1-oxide 1 e und f führen mit Trifluoressigsäure dagegen unter Abspaltung von H2O zu den Δ3-1,2,3-Thiadiazolinen 4e bzw. f. Für die Bildung der Ringverengungsprodukte werden zwei Reaktionswege vorgeschlagen. Die Struktur von 4e wurde durch Röntgenanalyse bestätigt.
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    URL: http://dx.doi.org/10.1002/cber.19781110532
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    Die Reaktion von β-Aminovinylcarbonylverbindungen mit Diphenylcarbodiimid (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2003-2009 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Reaction of β-Aminovinylcarbonyl Compounds with DiphenylcarbodiimideThe cyclization of 3-amino-2-alkylpropenals 1 with diphenylcarbodiimide (2) yields 5-alkyl-1-phenylpyrimidin-2(1H)-phenylimines 4. No corresponding reaction is observed with dicyclo-hexylcarbodiimide. 4-Amino-3-penten-2-one (5) reacts with diphenylcarbodiimide (2) as a CH acidic compound, i.e. involving addition to 4-amino-3-(N,N′-diphenylamidino)-3-penten-2-one (7). The corresponding addition to ethyl β-aminocrotonate (6) is observed to give 8. The constitution of the products 4, 7, and 8 is in accordance with the IR-, 1H- and 13C NMR spectra.
    Notes: 3-Amino-2-alkylpropenale 1 cyclisieren mit Diphenylcarbodiimid (2) zu 5-Alkyl-1-phenyl-pyrimidin-2(1H)-phenyliminen 4. Mit Dicyclohexylcarbodiimid wird keine entsprechende Reaktion beobachtet. 4-Amino-3-penten-2-on (5) reagiert mit Diphenylcarbodiimid (2) wie eine CH-acide Verbindung, d. h. unter Addition zu 4-Amino-3-(N,N′-diphenylamidino)-3-penten-2-on (7). Die entsprechende Addition zu 8 wird auch für β-Aminocrotonsäure-ethylester (6) beobachtet. Die Konstitution der Verbindungen 4, 7 und 8 stimmt mit den IR-, 1H- und 13C-NMR-Spektren überein.
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    URL: http://dx.doi.org/10.1002/cber.19781110534
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    Barrieren der behinderten Rotation um die N-glycosidische Bindung, II: 1-(α-D-Mannopyranosyl)isocyanursäuren (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2010-2020 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Barriers to Hindered Rotation Around the N-Glycosidic Bond, II: 1-(α-D-Mannopyranosyl)isocyanuric AcidsSyntheses of the 1-(α-D-mannopyranosyl)isocyanuric acids 2a--c and 3 are reported. According to the 1H-NMR spectra these compounds form in solution dynamic equilibria of flexible conformations (oS2) with pseudoequatorial aglyca. For the tetra-O-acetyl compound 2b an X-ray analysis has been performed (orthorhombic P212121; R-value 0.057). In the crystalline state 2b has 4C1 conformation, flattened at the C1′-end, with axial aglycon. The isocyanuric acid ring is almost perpendicular to the C1′ - O5′ bond and is partly lying under the sugar ring. The barrier to hindered rotation around the N-glycosidic bond of 2b as determined by 13C-NMR spectroscopy in solution is ΔG198≠ = 41.8 ± 1.3 kJmol-1. This barrier is considerably lower than the corresponding barrier of 1-(β-D-glucopyranosyl)isocyanuric acids2).
    Notes: Es werden Synthesen der 1-(α-D-Mannopyranosyl)isocyanursäuren 2a-c und 3 beschrieben. Nach den 1H-NMR-Spektren liegen die Verbindungen in Lösung in dynamischen Gleichgewichten flexibler Konformationen (oS2) mit pseudoäquatorialem Aglycon vor. Die Tetra-O-acetyl-Verbindung 2b wurde einer Röntgenstrukturanalyse unterworfen (orthorhombisch P212121; R-Wert 0.057). Im Kristall hat 2b eine am C1′-Ende abgeflachte 4C1-Sesselkonformation mit axialem Aglycon. Der Isocyanursäurering steht nahezu senkrecht auf der Bindung C1′ - O5′ und liegt damit teilweise unter dem Zuckerring. Die in Lösung mittels 13C-NMR-Spektroskopie gemessene Barriere der behinderten Rotation um die N-glycosidische Bindung von 2b beträgt ΔG198≠ = 41.8 ± 1.3 kJmol-1 und ist damit erheblich niedriger als die entsprechende Barriere der 1-(β-D-Glucopyranosido)isocyanursäuren2).
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19781110535
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    Röntgenographische Kristallstrukturbestimmung von (N′N′-Dimethylhydrazino)triphenylphosphonium-bromid (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2037-2046 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Crystal Structure Determination of (N′N′-Dimethylhydrazino)triphenylphosphonium Bromide by X-Ray TechniqueThe structure of the title compound has been determined by X-ray cristal structure analysis and was refined to R = 0.049 (Rw = 0.041). The P—N bond distance and the geometry of the nitrogen in α-position were compared with structurally analogous phosphor nitrogen compounds. The bond distance, which is relatively short for a P—N single bond, gives an explanation for the known reactions of the hydrazinophosphonium salts with nitrosation reagents.
    Notes: Die Kristallstruktur der Titelverbindung wurde röntgenographisch bestimmt und bis zu einem R-Faktor von 0.049 (Rw = 0.041) verfeinert. Der P—N-Bindungsabstand und die Geometrie am α-ständigen Stickstoffatom werden mit struktur-ähnlichen Phosphorstickstoff-Verbindungen verglichen. Der für eine P—N-Einfachbindung relativ kurze Abstand ist eine Erklärung für die bekannten Umwandlungen der Hydrazinophosphonium-Salze mit Nitrosierungsreagenzien.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110538
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    Reaktionen von Komplexliganden, XI: Stereoselektivität der Einschiebung von Inaminen in die Chrom-Carbenkohlenstoff-Bindung: erster Schritt einer zweistufigen Synthese von Indanon- und Indenon-Derivaten (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2059-2063 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reactions of Complex Ligands, XI: Stereoselectivity of the Insertion of Ynamines into the Chromium Carbene Bond: First Step of a Two-Step Synthesis of Indanone and Indenone DerivativesPentacarbonyl[methoxymethyl(or phenyl)carbene]chromium (1, 2) reacts with 1-(dialkylamino)-acetylenes (3, 4) in a stereoselective way to give E- and Z-pentacarbonyl(alkenylaminocarbene)-chromium complexes (5-7) via insertion of the alkyne into the metal-carbene bond. The thermolysis of pentacarbonyl[(diethylamino)-E-(β-methoxy-α-methylstyryl)carbene]chromium (7a) in n-decane results in the formation of the tricarbonylchromium complexes of 2-methyl-1-indenone (8) and trans-3-methoxy-2-methyl-1-indanone (9).
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110543
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  • 70
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    Oxidative Addition von Hexafluoraceton und Hexafluorbiacetyl an Phosphor(III)-fluoride RR′PF: Synthese chiraler 1,3,2-Dioxaphospholane und 1,3,2-Dioxaphospholene (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2077-2085 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Oxidative Addition of Hexafluoroacetone and Hexafluorobiacetyl to Phosphorus(III) Fluorides RR′PF: Synthesis of Chiral 1,3,2-Dioxaphospholanes and 1,3,2-DioxaphospholenesHexafluoroacetone and hexafluorobiacetyl react with fluorophosphines and fluorophosphites in an oxidative addition to form stable cyclic oxyphosphoranes containing the 1,3,2-dioxaphospholane (2) or 1,3,2-dioxaphospholene ring system (3). 19F and 31P NMR spectra are reported. The temperature dependency of the 19F NMR spectra in the range between -90 and +110°C is discussed in the light of pseudorotation processes at phosphorus(V).
    Notes: Hexafluoraceton und Hexafluorbiacetyl reagieren mit Fluorphosphinen und Fluorphosphiten unter Bildung stabiler cyclischer Oxyphosphorane mit dem 1,3,2-Dioxaphospholan- (2) bzw. Dioxaphospholen-Ringsystem (3). 19F- und 31P-NMR-Spektren werden mitgeteilt. Die Temperaturabhängigkeit der 19F-NMR-Spektren im Bereich von -90 bis +110°C wird auf der Basis von Pseudorotationsprozessen am Phosphor(V) diskutiert.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110603
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  • 71
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    Addition von Dibortetrahalogeniden an ungesättigte Kohlenwasserstoffe (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2108-2112 
    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 Diborontetrahalides to Unsaturated HydrocarbonsB2Cl4 and B2F4 add on the C = C-bond of methylenecyclopropane or vinylcyclopropane forming the diboryl compounds 3 and 5 respectively, C—C-bonds of the cyclopropane rings are not cleaved even using an excess of B2Cl4. The properties of the new compounds and their spectroscopic data are listed.
    Notes: B2Cl4 und B2F4 addieren sich an die C = C-Bindung von Methylencyclopropan bzw. Vinylcyclopropan unter Bildung der Diborylverbindungen 3 bzw. 5. C—C-Bindungen der Cyclopropanringe werden auch bei einem Überschuß von B2Cl4 nicht gespalten. Die Eigenschaften der neuen Verbindungen und ihre spektroskopischen Daten sind aufgeführt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110606
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  • 72
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    Darstellung und einige Eigenschaften von Silylderivaten des 2-Tetrazens und -Pentazens (Versuche zur Darstellung von cis-2-Tetrazen und -Pentazen) (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2123-2129 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation and Some Properties of Silyl Derivatives of 2-Tetrazene and -Pentazene (Attempts for the Preparation of cis-2-Tetrazene and -Pentazene)Oxidation of [(Me3Si)2N2Li]2SiMe2 (2) with benzenesulfonyl azide or ethyl nitrite yields a cyclic silyltetrazene (4) and -pentazene (6), respectively. Thermolysis of 4 causes ring opening and formation of (Me3Si)2NSiMe2N3 (9), whereas thermolysis of 6 leads to ring reorganisation with formation of the heterocycle 10a. Protolysis of 4 with trifluoroacetic acid gives ammonium azide  -  possibly via cis-2-tetrazene  - , protolysis of 6 yields nitrogen, ammonia, hydrazine, and hydrazoic acid  -  possibly via pentazene.
    Notes: Aus [(Me3Si)2N2Li]2SiMe2 (2) entsteht durch Oxidation mit Benzolsulfonylazid bzw. Ethylnitrit ein cyclisches Silyltetrazen (4) bzw. Silylpentazen (6. 4 thermolysiert unter Ringöffnung zu (Me3Si)2NSiMe2N3 (9), 6 unter Ringumlagerung zum Heterocyclus 10a. Die Protolyse mit Trifluoressigsäure führt im Falle von 4  -  möglicherweise über cis-2-Tetrazen  -  zum Ammoniumazid, im Falle von 6  -  möglicherweise über Pentazen  -  zu Stickstoff, Ammoniak. Hydrazin und Stickstoffwasserstoffsäure.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110609
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  • 73
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    Mesoionische Sechsringheterocyclen, X: Synthese und Reaktionen mesoionischer 1,2,3-Triazine (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2173-2178 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Mesoinoic Six-membered Heterocycles, X: Synthesis and Reactions of Mesoionic 1,2,3-TriazinesThe reaction of (chloroformyl)ketenes 2 with triazenes 3 in ether yields mesoionic 1,2,3-triazines 4. The structure of these compounds is substantiated by solvolysis and hydrogenation reactions. At 140°C compound 4a looses azobenzene (9) and nitrogen to give the 3,3′-biazetidinetetraone 8.
    Notes: Die Reaktion der (Chlorformyl)ketene 2 mit Triazenen (3) in Ether liefert mesoionische 1,2,3-Triazine (4). Die Struktur dieser Verbindungen wird durch Solvolysereaktionen sowie katalytische Hydrierungen gestützt. Die Verbindung 4a reagiert bei 140°C unter Verlust von Azobenzol (9) und Stickstoff zum 3,3′-Biazetidintetraon 8.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110613
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  • 74
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    Stereochemie der Metall-Metall-Bindungen: Die Kristallstruktur von Cr2(CO)7(C5H5)As(CH3)2 (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2199-2205 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stereochemistry of Metal-Metal Bonds: Crystal Structure of Cr2(CO)7(C5H5)As(CH3)2The crystal structure of the title complex 1 has been determined. Crowding of ligands in the molecule results in the very long Cr—Cr bond distance of 319 pm. A comparison with the structures of related complexes of manganese and iron shows the systematic influence of the number of ligands on the metal-metal bond lengths.
    Notes: Die Kristallstruktur des Titel-Komplexes 1 wurde bestimmt. Häufung von Liganden im Molekül bewirkt den mit 319 pm sehr großen Cr—Cr-Bindungsabstand. Ein Vergleich mit den Strukturen verwandter Komplexe des Mangans und Eisens belegt den systematischen Einfluß der Ligandenzahl auf die Metall-Metall-Bindungslängen.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110616
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  • 75
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    3-Diazoindazole: Photochemie, Thermochemie, Cycloadditionen (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2258-2266 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 3-Diazoindazoles: Photochemistry, Thermochemistry, CycloadditionsOn photolysis or thermolysis the 3-diazoindazole 1 a eliminates nitrogen with formation of the carbene 2. This rearranges via a nitrene intermediate 3 to the azo-compound 6. In the presence of electron-rich olefines and alkynes the 3-diazoindazoles 1 react also as dipoles with inverse electron demand affording triazino-indazoles 9.
    Notes: Die Photolyse oder Thermolyse des 3-Diazoindazols 1 a liefert unter Stickstoffabspaltung das Carben 2, das sich über eine Nitrenzwischenstufe 3 unter Bildung der Azoverbindung 6 stabilisiert. Weiterhin stellen die 3-Diazoindazole 1 Dipole mit inversem Elektronenbedarf dar, die mit elektronenreichen Alkinen bzw. Olefinen in einer neuen Reaktion die Triazino-indazole 9 liefern.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110620
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  • 76
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    Reaktionen an komplexgebundenen Carbenanalogen, II: Synthese und Schwingungsspektren von Pentacarbonyl[chlor-(di-tert-butylphosphino)stannylen]metall(VI A)-Komplexen (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2267-2272 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Complex-bound Carbene Analogues, II: Synthesis and Vibrational Spectra of Pentacarbonyl[chloro(di-tert-butylphosphino)stannio]-metal(VI A) ComplexesThe tindichloride complexes pentacarbonyl(dichlorotetrahydrofurane-stannio)chromium(0) (1), -molybdenum(0) (2) and -tungsten(0) (3) react with di-tert-butyl(trimethylsilyl)phosphine with elimination of tetrahydrofurane and formation of chlorotrimethylsilane to give the new, base free stannio complexes (CO)5M—Sn(Cl)[P(tBu)2] (4-6: M = Cr, Mo, W) with 75 to 85% yield. The ligand properties of chloro(di-tert-butylphosphino)-stannandiyl (-stannylene) are discussed on the basis of infrared and Raman data, and other physical properties.
    Notes: Die SnCl2-Metallkomplexe Pentacarbonyl(dichlortetrahydrofuran-stannio)chrom(0) (1), -molybdän(0) (2) und -wolfram(0) (3) reagieren mit Di-tert-butyl(trimethylsilyl)phosphin unter Verdrängung von Tetrahydrofuran und Eliminierung von Chlortrimethylsilan, wobei die neuen basenfreien Stannylenkomplexe (CO)5M—Sn(Cl)[P(tBu)2] (4-6: M = Cr, Mo, W) in 75-85 proz. Ausbeute erhalten werden. Die Ligandeneigenschaften von Chlor(di-tert-butylphosphio)stanandiyl (-stannylen) werden anhand von IR- und Raman-Daten sowie der physikalischen Eigenschaften von Ligand und Komplexen diskutiert.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19781110621
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    Untersuchungen an Diazoverbindungen und Aziden, XXX: C-Alkylierung von Diazomethylphosphorylverbindungen mit Enaminen (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2290-2296 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Investigations on Diazo Compounds and Azides, XXX: C-Alkylation of (Diazomethyl)phosphoryl Compounds with EnaminesThe phosphoryl diazomethanes 1a and b react with the enamines 2a-d to form the β-amino-α-diazophosphoryl compounds 3a-f. Addition of perchloric acid and hydrogen chloride, respectively, yields the ammonium salts 4a-f. It seems to be plausible, that the alkylation reaction proceeds via the intermediates 5 and 7.
    Notes: Die Phosphoryldiazoalkane 1a und b reagieren mit den Enaminen 2a-d zu den β-Amino-α-diazophosphorylverbindungen 3a-f. Addition von Perchlorsäure bzw. Chlorwasserstoff liefert die Ammoniumsalze 4a-f. Es erscheint plausibel, daß die Alkylierungsreaktion über die Zwischenstufen 5 und 7 verläuft.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110624
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  • 78
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    Der Aufbau des Tetracyclo[4.1.0.02,4.03,5]heptan-Systems durch Addition halogensubstituierter Carbene an Benzvalen (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2307-2319 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Synthesis of the Tetracyclo[4.1.0.02,4.03,5]heptane System by Addition of Halogen-Substituted Carbenes to BenzvaleneDibromo-, dichloro-, difluoro-, chlorofluoro-, and chlorocarbene react with benzvalene (1) to give the corresponding 7-substituted tetracyclo[4.1.0.02,4.03,5]heptanes 2a-g, thus providing the first and simultaneously productive access to this highly strained ring system. With the exception of fluorine the halogen atoms are easily replaced by hydrogen, which results in a second mode of preparation of 7-endo-(2g) and 7-exo-monochlorotetracycloheptane (2f) and which also yields both of the monofluoro (2k, l) and monobromo derivatives (2h, i). Furthermore by this reaction the unsubstituted hydrocarbon 2m can be obtained in synthetically useful quantities. Under the catalysis of silver tetrafluoroborate 2m rearranges exothermally to cycloheptatriene. Likewise the dideuterio derivative 2n is transformed to 3,4-dideuteriocycloheptatriene (7a) free of isomers. The 1H and 19F NMR spectra reveal the outstanding ability of the tetracycloheptane skeleton to bring about long range coupling. Direct interactions through space are considered in the case of J4,7endo.
    Notes: Aus der Addition von Dibrom-, Dichlor-, Difluor-, Chlorfluor- und Chlorcarben an Benzvalen (1) gehen die entsprechenden 7-substituierten Tetracyclo[4.1.0.02,4.03,5]heptane 2a-g hervor. Ihr hochgespanntes Ringsystem erhält damit den ersten und gleichzeitig ergiebigen Zugang. Mit Ausnahme von Fluor lassen sich die Halogenatome leicht durch Wasserstoff ersetzen, wodurch 7-endo- (2g) und 7-exo-Monochlortetracycloheptan (2f) einen zweiten Syntheseweg erhalten, jeweils die beiden Monofluor- und Monobromderivate 2k und 1 bzw. 2h und i darstellbar sind und schließlich der unsubstituierte Grundkörper 2m in präparativ brauchbaren Mengen bereitet werden kann. 2m lagert unter Silber(I)-Ionen-Katalyse exotherm im Cycloheptatrien um; aus dem Dideuterioderivat 2n entsteht analog isomerenfreies 3,4-Dideuteriocycloheptatrien (7a). Die 1H- und 19F-NMR-Spektren enthüllen die vorzügliche Eignung des Tetracycloheptangerüsts zur Vermittlung von Fernkopplungen. Direkte Wechselwirkungen durch den Raum werden im Falle von J4,7endo in Betracht gezogen.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110626
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    Bausteine von Oligosacchariden, X: Synthese α-1→4- und α-1→3-verknüpfter Disaccharide der 2-Amino-2-desoxy-D-glucopyranose nach der Azid-Methode (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2348-2357 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Building Units for Oligosaccharides, X: Synthesis of α-1→4 and α-1→3 Linked Disaccharides of 2-Amino-2-deoxy-D-glucopyranose by the Azide MethodThe reactive 2-azido-β-chloride 7 reacts in the presence of silver perchlorate with the saccharides 6 and 14 stereoselectively to give the α-1→4 and α-1→3 linked disaccharides 8 and 15, respectively. The deblocked N-acetylated disaccharides 13 and 20 are obtained by acetolysis, hydrogenation, and hydrolysis of 8 and 15. The triacetate 16 can be transformed into a disaccharide building unit. 16 gives the α-bromide 21 with titanium tetrabromide. 21 is inverted to the β-chloride 22 which reacts stereoselectively with 14 to give the α-trisaccharide 23 (62%).
    Notes: Das reaktive 2-Azido-β-chlorid 7 reagiert in Gegenwart von Silberperchlorat mit den Kupplungskomponenten 6 und 14 stereoselektiv zu den α-1→4- und α-1→3-verknüpften Disacchariden 8 und 15. Durch Acetolyse, Hydrierung, Peracetylierung und Hydrolyse sind hieraus die beiden freien N-acetylierten Disaccharide 13 und 20 erhältlich. Das Triacetat 16 kann in einen Disaccharid-Syntheseblock umgewandelt werden. Mit Titantetrabromid liefert 16 das α-Bromid 21, das zum β-Chlorid 22 invertiert werden kann, 22 reagiert gleichermaßen stereoselektiv mit 14 zum α-Trisaccharid 23 (62%).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110629
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    Zur Tautomerie 2,5-disubstituierter Pyrrole (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2401-2406 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Tautomerism of 2,5-Disubstituted PyrrolesThe isomerization 1 ⇌ 2 has been investigated in acidic solutions. Equilibria could be observed in two instances starting from both sides at ambient temperature. Their positions have been determined by means of 1H NMR spectroscopy (1a:2a = 8:1; 1b:2b = 30:1), pyrroles (1c-1e) being observed only in the remaining instances. The relative stability of the tautomers 1 and 2 has been discussed.
    Notes: Die säurekatalysierte Isomerisierung 1 ⇌ 2 wurde untersucht. In zwei Fällen konnten bei Raumtemperatur Gleichgewichte beobachtet und 1H-NMR-spektroskopisch quantitativ von beiden Seiten aus bestimmt werden (1a: 2a = 8:1; 1b: 2b = 30:1). In den übrigen untersuchten Fällen wurden lediglich Pyrrolisomere (1c-1e) beobachtet. Die Strukturabhängigkeit der relativen Stabilität der Tautomere 1 und 2 wird diskutiert.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110635
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    Iridoide, X: Stereospezifische Synthese von Iridoid-α-glucosiden (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2441-2444 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Iridoids, X: Stereospecific Synthesis of Iridoid-α-glucosidesTreatment of the iridoidaglycone 3 with 1,2-anhydro-α-D-glucopyranose triacetate (Brigls anhydride, 4) in the presence of a trace of boron trifluoride/ether led stereospecifically to the α-glucosides 7, 8, and 9, with 38% yield. In an analogous reaction 10 was formed from 2.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110638
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    Zur Kenntnis der Organophosphorverbindungen, XVIII: Bifunktionelle Dithiophosphinsäuren HS(S)P(R)—R′—P(R)(S)SH und einige ihrer Derivate (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 629-638 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On Organophosphorus Compounds, XVIII: Bifunctional Dithiophosphinic Acids HS(S)P(R)—R′—P(R)(S)SH and Some of Their DerivativesBifunctional dithiophosphinic acids are easily obtained by nucleophilic fission of perthiophosphonic anhydrides (RPS2)2 with di-Grignard reagents XMgR′MgX. By this method numercus compounds of the type XS(S)P(R)—R′—P(R)(S)SX (X = H, Na, NH4, (CH3)3NH; R = CH3, C6H5, 4-CH3OC6H4; R′ = 1,4′C6H4, [CH2]n with n = 4-10) were prepared. These could be easily converted into the corresponding esters, amides, and -chlorides as is shown by some examples. Oxidation of H4NS(S)P(R)—R′—P(R)(S)SNH4 (R = 4-CH3OC6H4; R′ = [CH2]6) with I2, CU2+, or Tl3+ gave a mixture of oligomeric disulfanes (—(S)P(R)—R′—P(R)(S)—S—S—)n (n = approx. 2-4), hydrolysis of the methyl ester CH3S(S)P(R)—R′—P(R)(S)SCH3 (R = 4-CH3OC6H4; R′ = 1,4-C6H4) gave the bifunctional monothiophosphinic acid HO(S)P(R)—R′—P(R)(S)OH.
    Notes: Durch nucleophile Spaltung von Perthiophosphonsäureanhydriden (RPS2)2 mit Di-Grignard-reagentien XMgR′MgX können bequem bifunktionelle Dithiophosphinsäuren XS(S)P(R)—R′—P(R)(S)SX (X = H, Na, NH4, (CH3)3NH; R = CH3, C6H5, 4-CH3OC6H4; R′ = 1,4-C6H4, [CH2]n mit n = 4-10) erhalten werden. Diese können leicht in die entsprechenden Ester, Säureamide und -chloride übergeführt werden, wie an einigen Beispielen gezeigt wird. Bei der Oxidation von H4NS(S)P(R)—R′—P(R)(S)SNH4 (R = 4-CH3OC6H4; R′ = [CH2]6) mit Iod, Cu2+ oder Tl3+ entstand ein Gemisch oligometer Disulfane [—(S)P(R)—R′—P(R)(S)—S—S—]n (n = ca. 2-4), bei der Hydrolyse des Methylesters CH3S(S)P(R)—R′—P(R)(S)SCH3 (R = 4-CH3OC6H4; R = 1,4-C6H4) die bifunktionelle Monothiophosphinsäure HO(S)P(R)—R′—P(R)(S)OH.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110222
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  • 83
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    Ein neues Syntheseprinzip für Furanderivate, II: Fragmentierung und recyclisierende Kondensation von 1,3-Dioxolan-4-ylium-Ionen (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 639-660 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A New Synthesis Principle for Furane Derivatives, II: Fragmentation and Recyclising Condensation of 1,3-Dioxolane-4-ylium IonsThermolysis of 2,2-dialkyl-4-benzoyloxy-1,3-dioxolanes (3), as well as protonation of 2,2-dialkyl-4-methylene-1,3-dioxolanes (9) and 2,2-dialkyl-4-methyl-1,3-dioxoles (10) primarily lead to 1,3-dioxolane-4-ylium ions (1) which fragmentate under the reaction conditions and recyclisingly condensate to furane derivatives.  -  The mechanism of this reaction is investigated and the preparative scope is traced out by variation of substituents. Treatment of 2-alkyl-4-benzoyloxy-2(2-bromoalkyl)-1,3-dioxolanes with zine leads via a complementary anionic pathway to corresponding furane derivatives.
    Notes: Die Thermolyse von 2,2-Dialkyl-4-benzoyloxy-1,3-dioxolanen (3) sowie die Protonierung von 2,2-Dialkyl-4-methylen-1,3-dioxolanen (9) und 2,2-Dialkyl-4-methyl-1,3-dioxolen (10) führen primär zu 1,3-Dioxolan-4-ylium-Ionen (1), die unter den Reaktionsbedingungen fragmentieren und recyclisierend zu Furanderivaten kondensieren.  -  Der Mechanismus dieser Reaktion wird untersucht und die präparative Leistungsfähigkeit durch Substituentenvariation abgesteckt. Die Behandlung von 2-Alkyl-4-benzoyloxy-2-(2-bromalkyl)-1,3-dioxolanen mit Zink führt auf einem komplementären anionischen Weg zu korrespondierenden Furanderivaten.
    Additional Material: 6 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110223
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  • 84
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    Cycloadditionsreaktionen von Heterocumulenen, XI: Umsetzung des monomeren und des dimeren tert-Butylcyanketens mit Azomethinen (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 661-672 
    Details
    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, XI: Reactions of Monomeric and Dimeric tert-Butylcyanoketene with AzomethinesOf the possible 2:1 adducts 4-7 of the ketene 1 and the azomethines 2a-d the 1,3-oxazinones 4 are obtained, whereas the dimeric ketene 15 reacts to give compounds of the type 5 or 6 (19). The cyclic azomethine 12 reacts with 1 to yield the 2:1 adduct 13. β-Lactames 9 can be obtained by pyrolysis of 4 (9a), addition of 1 to 2d (9b), or starting from the sterically hindered imine 2e (9c). The stereochemistry of the cycloadducts is discussed.
    Notes: Von den möglichen 2:1-Addukten 4-7 aus dem Keten 1 und den Azomethinen 2a-d werden die 1,3-Oxazinone 4 erhalten, während das dimere Keten 15 zu Verbindungen des Typs 5 oder 6 (19) reagiert. Das cyclische Azomethin 12 gibt mit 1 das 2:1-Addukt 13. β-Lactame 9 sind durch Pyrolyse von 4 (9a), Zugabe von 1 zu 2d (9b) oder aus dem sterisch gehinderten Imin 2e (9c) zugänglich. Die Stereochemie der Cycloaddukte wird diskutiert.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110224
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  • 85
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    Optisch aktive Übergangsmetall-Komplexe, LI: P-Liganden als optisch aktive Hilfsstoffe in den Komplexen C5H5M(CO)(NO)L, M = Cr, Mo, W (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 673-691 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Optically Active Transition Metal Complexes, LI: P-Ligands as Optically Active Resolving Agents in the Complexes C5H5M(CO)(NO)L, M = Cr, Mo, WFive new optically active ligands of the type PR2(NR′R″) and PR2(OR′) with chiral C-atoms in the substituents R′ (1a, c, d, 2, 5) were synthesized. These new ligands L as well as five known P-compounds of similar composition (1b, 3, 4, 6, 7) react with the prochiral complexes C5H5M(CO)2-(NO), M = Cr, Mo, W, to give the monosubstitution products C5H5(CO)(NO)L, in which the metal atom represents an asymmetric center. Investigations on the optical induction in the formation of the diastereoisomeric complexes C5H5M(CO)(NO)L, their 4H NMR differentiability, and their separability by preparative liquid chromatography and fractional crystallisation show the applicability of the ten ligands used for the preparation and resolution of chiral metal complexes.
    Notes: Fünf neue optisch aktive Liganden des Typs PR2(NR′R″) und PR2(OR′) mit chiralen C-Atomen im Substituenten R′ (1a, c, d, 2, 5) wurden synthetisiert. Die neuen Liganden L sowie fünf bekannte P-Verbindungen ähnlichen Aufbaus (1b, 3, 4, 6, 7) wurden mit den prochiralen Komplexen C5H5M(CO)2(NO), M = Cr, Mo, W, zu den Monosubstitutionsprodukten C5H5M(CO)(NO)L umgesetzt, in denen das Metallatom ein Asymmetriezentrum darstellt. Untersuchungen über die optische Induktion bei der Bildung der diastereomeren Komplexe C5H5M(CO)(NO)L, ihre 1H-NMR-Unterscheidbarkeit und ihre Trennbarkeit durch präparative Flüssigkeitschromatographie sowie fraktionierte Kristallisation demonstrieren die Anwendbarkeit der eingesetzten zehn Liganden als optisch aktive Hilfsstoffe bei der Darstellung und Racematspaltung chiraler Metallkomplexe.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110225
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  • 86
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    Verlängerung CH-acider Verbindungen um eine gerade Anzahl von Methingruppen durch Umsetzung mit Nitroenaminen (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 692-697 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Extension of CH-acidic Compounds by an Even Number of Methine Groups by the Reaction with NitroenaminesCH-acidic compounds 9, 16 with an active methyl- or a methylene group are expanded by four methine groups by the reaction with 1-dimethylamino-4-nitro-1,3-butadiene (8a) or its methyl derivative 8b to give 10, 17a, and 18. From these nitropolyenes (13), aromatic nitro compounds (11), azepines (15), and dicarbonyl compounds (19) are prepared.
    Notes: CH-acide Verbindungen 9, 16 mit einer aktivierten Methyl- oder Methylengruppe werden durch Umsetzung mit 1-Dimethylamino-4-nitro-1,3-butadien (8a) bzw. dessen Methylderivat 8b um vier Methingruppen verlängert. Die Produkte 10, 17a, 18 enthalten endständig eine aci-Nitro-Funktion. Durch Folgereaktionen sind Nitropolyene (13). Nitroaromaten (11). Azepine (15) und Dicarbonylverbindungen (19) darstellbar.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110226
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  • 87
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    Reaktionen von Schwefeldiimiden mit bifunktionellen Säurechloriden, II: Synthesen von 5-Oxo-5H-1,3λ4,2,4-dithiadiazol und 5-Acylimino-5H-1,3λ4,2,4-dithiadiazolen (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 698-704 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Sulfur Diimides with Bifunctional Acyl Chlorides, II: Syntheses of 5-Oxo-5H-1,3λ4,2,4-dithiadiazole and 5-Acylimino-5H-1,3λ4,2,4-dithiadiazolesAcyl isothiocyanates react with chlorine to give the N-acyl-1-(chlorothio)formimidoyl chlorides 1d-h; N,N′-bis(trimethylsilyl)sulfur diimide (2) reacts with 1-(chlorothio)formyl chloride (3) to yield 5-oxo-5H-1,3λ4,2,4-dithiadiazole (4), with 1a-h to form the 5-acylimino-5H-1,3λ4,2,4-dithiadiazoles 6a-h. 6d was alkylated at the carbonyl group by methyl fluorosulfonate (7) to give 8. The X-ray structure analysis of 6b is discussed.
    Notes: Die Reaktion von Chlor mit Acyl-isothiocyanaten führt zu den N-Acyl-1-(chlorthio)formimidoylchloriden 1d-h; N,N′-Bis(trimethylsilyl)schwefeldiimid (2) konnte mit 1-(Chlorthio)formylchlorid (3) zu 5-Oxo-5H-1,3λ4,2,4-dithiadiazol (4) gespalten werden, mit 1a-h zu 5-Acylimino-5H-1,3λ4,2,4-dithiadiazolen 6a-h; 6d wurde mit Fluorsulfonsäure-methylester (7) zu 8 alkyliert. Über die Röntgenstrukturanalyse von 6b wird berichtet.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110227
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  • 88
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    Synthese von [2]-[Azacyclohexacosan]-[cyclooctacosan]-catenan (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2615-2629 
    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 [2]-[Azacyclohexacosane]-[cyclooctacosane]-catenaneThe ozonolysis of the quinoid catenane 17 in ethyl acetate at -40°C in the presence of tetracyanoethylene followed by reduction with sodium borohydride and reductive elimination of the hydroxy groups affords the crystalline catenane 20 a with 24% yield, based on 16. By ozonolysis of 17 in ethyl acetate/methanol (10:1) at -26 C, subsequent reduction of the peroxidic intermediates with dimethyl sulfide, and reduction of the carbonyl groups a mixture of the catenane 20 a and the methyl- and ethyl-branched homologues 21 a and 22 a is obtained.
    Notes: Die Ozonolyse des chinoiden Catenans 17 in Ethylacetat bei -40°C in Gegenwart von Tetracyanethylen ergibt nach Reduktion mit Natriumboranat und anschließender reduktiver Eliminierung der Hydroxylgruppen in einer Gesamtausbeute von 24% (bezogen auf 16) das kristalline Catenan 20a. Die Ozonolyse von 17 in Ethylacetat/Methanol (10:1) bei -26°C führt nach Reduktion der peroxidischen Zwischenstufen mit Dimethylsulfid und Reduktion der Carbonylgruppen zu einem Gemisch der Catenans 20a und seiner methyl- und ethylverzweigten Homologen 21a und 22a.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110717
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  • 89
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    Cyclische Ketone aus 3,3-Dimethyl-1-cyclopropen und Kohlenmonoxid durch katalysierte Cotrimerisation (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2689-2695 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cyclic Ketones from 3,3-Dimethyl-1-cyclopropene and Carbon Monoxide by Catalyzed CotrimerisationThe tetracarbonylnickel-catalyzed cotrimerisation of 3,3-dimethyl-1-cyclopropene (1) and carbon monoxide gives 3,3,7,7-tetramethyl-trans-tricyclo[4.1.0.02,4]heptan-5-one (5) and 2-isopropyl-6,6-dimethylbicyclo[3.1.0]hex-2-en-4-one (6). Further products are the cyclodimer 2 and the cyclotrimers 3 and 4. - Tetracarbonylnickel is a poor catalyst for the codimerisation of 1 with methyl acrylate and methyl trans-crotonate.
    Notes: Tetracarbonylnickel katalysiert die Cotrimerisation von 3,3-Dimethyl-1-cyclopropen (1) und Kohlenmonoxid zu 3,3,7,7-Tetramethyl-trans-tricyclo[4.1.0.02,4]heptan-5-on (5) und 2-Isopropyl-6,6-dimethylbicyclo[3.1.0]hex-2-en-4-on (6). Außerdem entstehen aus 1 das Cyclodimere 2 sowie die Cyclotrimeren 3 und 4. - Eine Codimerisation von 1 mit Acrylsäure- sowie trans-Crotonsäure-methylester an Tetracarbonylnickel gelingt praktisch nicht.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110723
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  • 90
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    Synthese und Eigenschaften einiger silacyclischer Phosphor-ylide (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2696-2701 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses and Properties of Some Silacyclic Phosphorus YlidesA disilacyclobutane derivative with an exocyclic function (1) has been synthesized by the reaction of double-lithiated (CH3)3P = CH2 with CH2[Si(CH3)2Cl]2 and characterized by 1H, 13C, and 31P NMR spectroscopy. In this reaction varying amounts of an isomer 2 are also formed, in which the functional group is an integral part of the six-membered ring. Transsilylation of the same halosilane with (CH3)3P = C[Si(CH3)3]2 is accompanied by transylidation, yielding the octalene-analogous bicyclic ylide 4, the P = C moiety being shared by both rings. In corresponding reactions with the components (CH3)2Si[CH2Si(CH3)Cl2]2 and [CH2Si(CH3)2Cl]2 the strain-free ylides 5 and 6 are obtained.
    Notes: Durch die Umsetzung von doppelt lithiiertem (CH3)3 P = CH2 mit CH2[Si(CH3)2Cl]2 wurde ein Disilacyclobutanderivat (1) mit exocyclischer Ylidfunktion synthetisiert und 1H-, 13C- und 31P-NMR-spektroskopisch charakterisiert. Bei der gleichen Reaktion entstehen wechselnde Mengen eines Isomeren 2, in dem die funktionelle Gruppe in das Sechsringsystem integriert ist. Die Umsilylierung des gleichen Halogensilans mit (CH3)3P = C[Si(CH3)3]2 liefert unter nachfolgender Umylidierung den octalin-analogen Bicyclus 4, in dem die P = C-Einheit beiden Ringen gemeinsam ist. Mit den Komponenten (CH3)2Si[CH2Si(CH3)2Cl]2 und [CH2Si(CH3)Cl2]2 entstehen bei entsprechenden Ansätzen die spannungsfreien silacyclischen Ylide 5 und 6.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19781110724
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  • 91
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    [Bis(trimethylsilyl)isodiazen](cyclopentadienyl)metall-Komplexe: Synthese und Struktur (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2708-2715 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: [Bis(trimethylsilyl)isodiazene](cyclopentadienyl)metal Complexes: Synthesis and Structure1)The following complexes are formed by the reaction of Cp2TiCl2 or Cp2M (M = V, Cr, Mn; Cp = C5H5) with Me3Si-N = N-SiMe3: Cp2TiNN(SiMe3)2 (2), Cp2VNN(SiMe3)2 (1), [CpCrNN(SiMe3)2]2 (3), [CpMnNN(SiMe3)2]2 (4). While in the case of 2 (and possibly 1) the bis(trimethylsilyl)isodiazene ligand is terminally bound to the metal, according to X-ray analysis in the case of 4 (and possibly 3) NN(SiMe3)2 combines two metal atoms.
    Notes: Durch Reaktion von Cp2TiCl2 bzw. Cp2M (M = V, Cr, Mn; Cp = C5H5) mit Me3Si-N = N-SiMe3 bilden sich folgende Komplexe: Cp2TiNN(SiMe3)2 (2), Cp2VNN(SiMe3)2 (1), [CpCrNN(SiMe3)2]2 (3), [CpMnNN(SiMe3)2]2 (4). Während der Bis(trimethylsilyl)isodiazen-Ligand im Falle von 2 (und wahrscheinlich 1) terminal an das Metall gebunden ist, verbrückt NN(SiMe3)2 laut Röntgenstrukturanalyse im Falle von 4 (und wahrscheinlich 3) zwei Metallatome.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110726
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    Überbrückung des Anthrachinons in 1,8-Stellung (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2729-2731 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis of 1,8-Bridged AnthraquinonesThe 1,8-position of the anthraquinone system has been bridged by nucleophilic aromatic substitution of 1,8-dichloroanthraquinone with 1,ω-dithiolates, without using high dilution methods. Crown ether systems of type 4 are also obtained by this method.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110729
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  • 93
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    Synthese von 2,3,4,5,6,7-Hexachlor-8,8-dicyanheptafulven (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2738-2740 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis of 2,3,4,5,6,7-Hexachloro-8,8-dicyanoheptafulveneOn melting 1 with malononitrile and AlCl3 at 150°C 2 is formed which rearranges thermally or photochemically into the title compound 4. The structure of 4 is confirmed by its analogous synthesis from 3 as well as from spectroscopic data.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110732
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  • 94
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    Barrieren der behinderten Rotation um die N-glycosidische Bindung, III. N-Glycopyranoside (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2745-2756 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Barriers to Hindered Rotation Around the N-Glycosidic Bond, III1) N-Glycopyranosides2)The pyranosides of isocyanuric acid 4a-c, 5, 8b, 9a-c, 10a-d, 11a-c and 12 are prepared. The barriers to hindered rotation around the glycosidic bonds (Tab. 1) are determined by dynamic 1H NMR spectroscopy. The barriers are explained by steric repulsion of the carbonyls 2 and 6 of the aglycon and the sugar oxygens in 2′- and 5′-position2). Although the pentopyranosides 10 and 11 have 4C1 chair conformations in the ground state (Tab. 2), the rotations around the glycosidic bond proceed most likely through transition states with flexible sugar conformations. The isocyanuric acid glucoside 12 is degraded with base to the biuret 15.
    Notes: Die Isocyanursäurepyranoside 4a-c, 5, 8b, 9a-c, 10a-d, 11a-c und 12 werden dargestellt und die Barrieren der behinderten Rotation um die N-glycosidische Bindung (Tab. 1) mittels dynamischer 1H-NMR-Spektroskopie bestimmt. Die Rotationsbarriere wird durch sterische Wechselwirkungen der zur glycosidischen Bindung benachbarten Carbonylgruppen 2 und 6 des Aglycons und der Zuckersauerstoffe in 2′- und 5′-Position erklärt2). Obwohl die Pentopyranoside 10 und 11 im Grundzustand in Lösung in der 4C1-Sesselkonformation vorliegen (Tab. 2), verlaufen die Rotationen wahrscheinlich über Übergangszustände mit flexiblen Zuckerkonformationen. Das Isocyanursäureglucosid 12 wird in alkalischem Medium zum Biuret 15 abgebaut.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110802
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    Übergangsmetall-Carbin-Komplexe, XXXVI. Nucleophile Substitution an trans-Tetracarbonyl (organylcarbin)-(tetrafluoroborato)-Komplexen des Chroms und Wolframs mit Triphenylphosphin, Cyanid und Rhodanid (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2765-2773 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Transition Metal Carbyne Complexes, XXXVI. Nucleophilic Substitution on trans-Tetracarbonyl(organylcarbyne)(tetrafluoroborato) Complexes of Chromium and Tungsten with Triphenylphosphine, Cyanide and ThiocyanatePentacarbonyl[methoxy(phenyl)carbene]- and -[methoxy(methyl)carbene]tungsten(0) (1a, b) react in boron trifluoride dimethyletherate in the presence of a large excess of BF3 to form trans- (BF4)(CO)4WCR complexes (2a, b). In these two tungsten complexes 2a, b as well as in the analogous chromium complex mer-(BF4)(CO)3[P(CH3)3]CrCCH3 (4) the BF4 ligand is displaced easily by nucleophilic reagents. With thiocyanate, cyanide, and triphenylphosphine the corresponding neutral trans-isothiocyanato (6a, b) and trans-cyano complexes (7) as well as the cationic trans-(organylcarbyne)(triphenylphosphine)metal complexes (3, 5) are obtained similarly at low temperatures.
    Notes: Pentacarbonyl[methoxy(phenyl)carben]- und -[methoxy(methyl)carben]wolfram(0) (1a, b) reagieren in Bortrifluorid-dimethyletherat in Gegenwart eines großen Überschusses an BF3 zu trans- (BF4) (CO)4WCR-Komplexen (2a, b). Der am Metallatom koordinierte BF4-Ligand in den beiden Wolframkomplexen 2a, b sowie bei dem analogen Chromkomplex mer-(BF4)(CO)3-[P(CH3)3]CrCCH3 (4) kann durch nucleophile Reagentien leicht verdrängt werden. So lassen sich mit Rhodanid und Cyanid sowie Triphenylphosphin bei tiefen Temperaturen die entsprechenden neutralen trans-Isothiocyanato- (6a, b) und trans-Cyano-Komplexe (7) sowie die kationischen trans-(Organylcarbin)triphenylphosphin)metall-Komplexe (3, 5) erhalten.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110804
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  • 96
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    Brom/Lithium-Austausch an Vinylbromiden mit 2 Moläquivv. tert-Butyllithium. Umsetzungen von Vinyllithiumverbindungen mit Hetero- und Kohlenstoff-Elektrophilen (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2785-2812 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Br/Li-Exchange in Vinyl Bromides with 2 Molequivalents of tert-Butyllithium. Reactions of Vinyllithium Compounds with Hetero and Carbon ElectrophilesHaloalkane-free solutions of vinyllithium compounds 2 - terminal ones at temperatures below -110°C  -  in THF or ether are generated from vinyl bromides 1 with two molequivalents of tert-butyllithium [eq. (1)]. The scope and limitations of the method are discussed. Iodinations, silylations, sulfenylations, and oxygenations leading to 4, 5, 6, and 8, respectively, are described (table 1). The usefulness of these reactions in the synthesis of carbonyl compounds is compared with that of alternative recent methods. Examples of the stereoselective preparation of allylic alcohols 10, α,β-unsaturated carbonyl compounds 11 and olefins 12 by addition of 2 to aldehydes and ketones and acylation (table 2) or alkylation are given. In the alkylations of cyclic representatives 2j-n with iodomethane, it was noticed that it is important to work in THF solvent and to avoid excess halide. Otherwise (table 3 and 4) vinyl iodides 4 can be the main products instead of the desired methylated compounds 13.
    Notes: Alkylhalogenidfreie Ether- oder THF-Lösungen von Vinyllithiumverbindungen 2 - unterhalb von -110°C auch endständige - sind durch Umsetzung von Vinylbromiden 1 mit 2 Moläquivv. tert-Butyllithium nach Gleichung (1) leicht zugänglich. Die Grenzen der Methode werden diskutiert. Iodierungen, Silylierungen, Sulfenylierungen und Oxygenierungen zu 4, 5, 6 bzw. 8 werden beschrieben (Tab. 1). Die Bedeutung dieser Reaktionen für die Herstellung von Carbonylverbindungen wird mit der alternativer Verfahren verglichen. Beispiele für die stereoselektive Synthese von Allylalkoholen 10, α,β-ungesättigten Carbonylverbindungen 11 und Olefinen 12 durch Carbonyladdition und Acylierung (Tab. 2) bzw. Alkylierung von 2 werden angegeben. Bei der Methylierung der Cycloalkenyllithiumverbindungen 2j-n mit Methyliodid ist es wichtig, daß man THF als Lösungsmittel verwendet und überschüssiges Alkylierungsmittel vermeidet, da sonst neben oder statt der gewünschten C—C-Verknüpfungsprodukte 13 Vinyliodide 4 entstehen (Tabellen 3 und 4).
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110807
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  • 97
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    Darstellung und Eigenschaften (trifluormethylthio)-substituierter Carbonylverbindungen (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2891-2894 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation and Properties of (Trifluoromethylthio)-substituted Carbonyl CompoundsHalogene exchange reaction of CF3SC(O)F with BBr3 leads to CF3SC(O)Br, a good starting material for synthesizing compounds of the type CF3SC(O)X (X = CN, NCO, NCS, OC(O)CF3, CF3, SeCF3, and NH2).
    Notes: Durch Halogenaustausch mit BBr3 läßt sich CF3SC(O)F in CF3SC(O)Br überführen. Dieses ist ein gutes Ausgangsreagenz zur Synthese von Verbindungen des Typs CF3SC(O)X (X = CN, NCO, NCS, OC(O)CF3, CF3, SeCF3 und NH2).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110815
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  • 98
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    (C6H6)n-Kohlenwasserstoffe. Über spezifische Reaktionen am Bicyclo[2.2.2]octadienteil des Hexacyclo[9.3.2.24,7 .02,9 .03,8 .010,12]octadeca-5,13,15,17-tetraens (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2877-2890 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: (C6H6)n-Hydrocarbons1) Specific Reactions at the Bicyclo[2.2.2]octadiene Part of Hexacyclo[9.3.2.24,7 .02,9 .03,8 .010,12]-octadeca-5,13,15,17-tetraeneThe title compound 1 contains diastereotopic double bonds in the homotropilidene and bicyclo-[2.2.2]octadiene parts. The non-conjugated diene part reacts with Fe2 (CO)9 to give the tricarbonyliron complex 14 in 41% yield. By hydrogenation in the presence of the homogenous catalyst tris(triphenylphosphine)rhodium(1) chloride (2) only the 5,6-double bond is saturated. Assignement of the double bonds was achieved with the help of specifically deuterated samples. The results are discussed.
    Notes: Die Titelverbindung 1 enthält diastereotope Doppelbindungen im Homotropiliden- und Bicyclo-[2.2.2]octadienteil. Mit Fe2 (CO)9 reagiert der nichtkonjugierte Dienteil mit 41% Ausbeute zum Tricarbonyleisen-Komplex 14. Bei der Hydrierung mit dem homogenen Tris(triphenylphosphin)-rhodium(1)-chlorid-Katalysator (2) wird nur die 5,6-Doppelbindung abgesättigt. Die Zuordnung der Doppelbindungen erfolgte 1H-NMR-spektroskopisch an Hand spezifisch deuterierter Proben. Die Resultate werden diskutiert.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110814
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  • 99
    Electronic Resource
    Electronic Resource
    Anhydrozucker mit 2,7-Dioxabicyclo[2.2.1]heptan-System: 2,6-Anhydrohexulosen (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2909-2912 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Anhydro Sugars with 2,7-Dioxabicyclo[2.2.1]heptane System: 2,6-AnhydrohexulosesVacuum pyrolysis of the free ketoses D-fructose, D-tagatose, D-psicose, and L-sorbose gives the corresponding 2,6-anhydro sugars 1a-4a purified via the acetates 1b-4b in yields of about 1%. 1a is also prepared from inulin. 270 MHz 1H NMR spectra of the acetates are completely interpreted.
    Notes: Vakuumpyrolyse der freien Ketosen D-Fructose, D-Tagatose, D-Psicose und L-Sorbose liefert die 2,6-Anhydrozucker 1a-4a nach Reinigung über die Acetate 1b-4b in Ausbeuten um ca. 1%. 1a kann auch aus Inulin erhalten werden. Die 270-MHz-1H-NMR-Spektren der Acetate konnten vollständig interpretiert werden.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110818
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  • 100
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    Electronic Resource
    Versuche zur Darstellung von (R,S)-2,7-Dioxabicyclo[2.2.1]-heptan ( = 1,5-Anhydro-2,3-didesoxy-β-D-glycero-pentofuranose = 1,4-Anhydro-2,3-didesoxy-α-D-glycero-pentopyranose) (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 2913-2918 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation of (R,S)-2,7-Dioxabicyclo[2.2.1]heptane ( = 1,5-Anhydro-2,3-dideoxy-β-D-glycero-pentofuranose = 1,4-Anhydro-2,3-dideoxy-α-D-glycero-pentopyranose)Corey-Winter elimination of the thionocarbonate 2 of 1,5-anhydro-β-D-ribofuranose (1) does not yield the unsaturated derivative 3 and therefore attempts to prepare the title compound 12 via 3 failed. Instead the orthoester 4 is formed. On the other hand the elimination reaction of the derivative 6 of methyl 5-O-trityl-D-ribofuranoside (5) proceeds smoothly. Hydrogenation and hydrogenolysis of the unsaturated sugar 9 gives the anomers of methyl 2,3-dideoxy-D-glycero-pentofuranoside (11). which can be cyclisized in moderate yield to the bicyclus 12.
    Notes: Corey-Winter-Eliminierung aus dem Thionocarbonat 2 der 1.5-Anhydro-β-D-ribofuranose (1) zum ungesättigten Derivat 3 gelingt nicht und somit auch nicht die Darstellung der Titelverbindung 12 auf diesem Wege. Stattdessen entsteht der Orthoester 4. Hingegen gelingt die Eliminierungsreaktion am Derivat 6 des Methyl-5-O-trityl-D-ribofuranosids (5) leicht. Vollständige Hydrierung des Olefinzuckers 9 führt zu den Anomeren des Methyl-2,3-didesoxy-D-glycero-pentofuranosids (11). die sich in geringer Ausbeute zum Bicyclus 12 cyclisieren lassen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110819
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