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  • 1985-1989
  • 1980-1984  (789)
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  • 1890-1899
  • 1980  (789)
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  • 1985-1989
  • 1980-1984  (789)
  • 1965-1969  (865)
  • 1940-1944
  • 1890-1899
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  • 1
    Electronic Resource
    Electronic Resource
    Cumulative effect of brief daily periods of monocular vision on kitten striate cortex (1980)
    Springer
    Experimental brain research 38 (1980), S. 53-56 
    Details
    ISSN: 1432-1106
    Keywords: Cat ; Monocular deprivation ; Visual cortex
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Eight kittens were subjected to daily 4-h sessions with vision restricted to one eye between the 4th and 9th postnatal weeks. The total duration of monocular exposure ranged from 76 to 152 h. Between monocular exposure periods, four kittens were kept in total darkness, and four experienced binocular vision under normal colony conditions. At the end of the rearing period, all experimental animals and four normally reared controls were studied by means of single-unit recording in primary visual cortex. In kittens with inter-session dark rearing, very few neurons could be driven through the deprived eye. This effect was more extreme than that observed after continuous dark rearing. Visual responses mediated by the experienced eye appeared normal. In contrast, in kittens with inter-session binocular vision, the large majority of visual cortical neurons responded to visual stimulation of either eye. A few neurons appeared to have lost their responsiveness to the deprived eye, but this effect was small. We conclude that monocular vision delivered during brief daily sessions produces a cumulative competitive inactivation of transmission in the pathway from the deprived eye to striate cortex so long as no visual stimulation occurs outside the monocular periods. Binocular visual stimulation received between sessions rapidly and almost completely reverses the effects of monocular vision.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237930
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  • 2
    Electronic Resource
    Electronic Resource
    Development of binaural input, response patterns, and discharge rate in single units of the cat inferior colliculus (1980)
    Springer
    Experimental brain research 38 (1980), S. 103-108 
    Details
    ISSN: 1432-1106
    Keywords: Cat ; Auditory ; Binaural ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The binaural input to single neurones in the inferior colliculus of barbiturate- and ketamine-anaesthetised kittens was tested using pure tones. Stimuli were presented to each ear independently via sealed sound-delivery systems. Cells were classified according to the predominant type of input (excitatory or inhibitory) from each ear. There was no significant difference between age groups in the proportions of cells showing each type of binaural input. For all ages, cells excited by monaural stimulation of either ear (EE cells) tended to be of low best frequency (BF) and cells excited by monaural stimulation of one ear, but inhibited by simultaneous stimulation of the other ear (EI cells), had higher BFs. Units for which quantitative spike count data were obtained were also categorised according to their response pattern. Cells categorised as “onset”, “pauser” and “burst-type” were found in approximately equal proportions in animals of all age groups. “Primary-like” units were not found in animals less than 20 days old. Unit discharge rate was significantly higher for adults than for any of the three kitten groups. These data suggest that (1) binaural connections are not subject to postnatal developmental alteration and (2) the development of excitatory responses after 20 days consists of an increase in the number of discharges rather than a change in the pattern of these discharges.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237936
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  • 3
    Electronic Resource
    Electronic Resource
    A direct pathway from thalamus to visual callosal neurons in cat (1980)
    Springer
    Experimental brain research 38 (1980), S. 121-123 
    Details
    ISSN: 1432-1106
    Keywords: Cat ; Visual cortex ; Corpus callosum ; Horseradish peroxidase ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Horseradish peroxidase was injected in the right visual cortex and a large electrolytic lesion made in the left lateral geniculate nucleus of an adult cat. Neurons of origin of the callosal projection to the injected cortex were identified by retrograde labelling and selected for electron microscopic study. Degenerating thalamo-cortical axon terminals were found to contact a labelled stellate cell in layer IV and a labelled pyramidal cell in layer III at the border region of areas 17 and 18. We conclude that there is a monosynaptic pathway from lateral geniculate nucleus to the cells of origin of callosal axons to the contralateral visual cortex.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237940
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  • 4
    Electronic Resource
    Electronic Resource
    Ultrastructure of degenerating cerebellothalamic terminals in the ventral medial nucleus of the cat (1980)
    Springer
    Experimental brain research 38 (1980), S. 125-135 
    Details
    ISSN: 1432-1106
    Keywords: Ventromedial thalamic nucleus ; Cerebellar degenerating boutons ; Ultrastructure ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Terminal degeneration of cerebellar afferents in the ventral medial thalamic nucleus (VM) was studied in cats at the ultrastructural level after uni- or bilateral lesions in the brachium conjunctivum (BC). To achieve discrete lesions within the BC, a new very accurate stereotaxic technique was used. Numerous large terminals belonging to a population of so-called LR boutons were observed degenerating in the VM. The boutons displayed a wide variety of degenerative changes. Some revealed the features of the classical neurofilamentous type of degeneration. Others, although containing a slightly increased number of neurofilaments, featured much more prominently large numbers of coated vesicle shells and heavy accumulations of a flocculent electrondense material. Degeneration in a third group of boutons similar to some extent to the light type of degeneration was characterized by tight clumping of enormously swollen or distorted synaptic vesicles within a light matrix. At later stages, however, all these boutons were believed to become shrunken and electron-dense since intermediate stages between the light- and dark-appearing boutons were observed. The degenerating cerebellar boutons formed asymmetrical synaptic contacts. Groups of 3 or 4 boutons terminated upon dendrites of projection neurons synapsing more frequently on spines than on dendritic stems. The synaptic contacts between cerebellar boutons and the vesicle-containing dendrites of local circuit neurons were encountered as often if not more than the contacts on projection neuron dendrites. Triads consisting of cerebellar boutons and dendrites of both types of neurons were observed very regularly. This synaptic arrangement provides the anatomical basis for the modification of cerebellar input in the VM by interneurons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236734
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  • 5
    Electronic Resource
    Electronic Resource
    Stimulation of the superior colliculus in the alert cat (1980)
    Springer
    Experimental brain research 39 (1980), S. 63-73 
    Details
    ISSN: 1432-1106
    Keywords: Cat ; Stimulation ; Superior colliculus ; Eye movements ; Eye-head coordination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Electrical stimulation of the cat superior colliculus (SC), in conjunction with the accurate measurement of elicited eye movements and histologically verified electrode positions, has revealed a striking antero-posterior variation in collicular organization. Three zones could be defined in the SC on the basis of eye movement patterns and associated neck muscle EMG activity evoked from the deeper layers. The Anterior zone was coextensive with the central 25 ° of the visual retinotopically coded map contained in the superficial layers. Saccades evoked from this zone were also retinotopically coded, and the latency of EMG activity depended on the position of the eye in the orbit. A similar observation applies to the entire monkey SC. The Intermediate zone was coextensive with the 25 °–70 ° of visual projections. Saccades evoked from this region were “goal-directed” and were associated with invariant, short latency EMG responses. The Posterior zone was found in the extreme caudo-lateral portion of the SC. Eye movements evoked from this zone were centering saccades associated with constant latency EMG activity. The present results in conjunction with previously demonstrated antero-posterior variations in projections to the SC, suggest that the motor strategies controlling gaze shifts toward visual targets vary depending on the location of the target in the visual field.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237070
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  • 6
    Electronic Resource
    Electronic Resource
    Prefrontal cortex of the cat: Paucity of afferent projections from the parietal cortex (1980)
    Springer
    Experimental brain research 39 (1980), S. 105-112 
    Details
    ISSN: 1432-1106
    Keywords: Cat ; Prefrontal cortex ; Parietal cortex ; Mediodorsal thalamic nucleus ; Horseradish peroxidase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Twenty-one cat brains with cortical injections of horseradish peroxidase resulting in labelled cells in the thalamic mediodorsal nucleus (MD) were screened for afferent projections from the parietal cortex. Contrary to expectation, nearly the whole prefrontal cortex (PFC) situated around the frontal pole was free of parietal afferents, while a small area in the anterior sylvian gyrus (orbito-insular subregion of PFC) consistently received afferents from the parietal cortex. The few afferents projecting to the cortex around the frontal pole originated exclusively from the convexity of the suprasylvian gyrus, while the great majority of the parietal neurons projecting to the anterior sylvian gyrus was situated within the fundus of the suprasylvian sulcus. While the main regions of the prefrontal cortex of the rhesus monkey receive a substantial projection from the parietal lobe, whereas the main regions of the cat's prefrontal cortex are free of afferents from the parietal cortex, possible differences in the parieto-prefrontal organization of both species are discussed. Furthermore, differences between the orbito-insular subregion and the rest of the PFC are emphasized.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237073
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  • 7
    Electronic Resource
    Electronic Resource
    Rarity of luxotonic responses in cortical visual areas of the cat (1980)
    Springer
    Experimental brain research 39 (1980), S. 125-132 
    Details
    ISSN: 1432-1106
    Keywords: Cat ; Visual cortex ; Luxotonic sustained responses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Neuronal responses to continuous, diffuse white light or darkness were studied in cortical visual areas 17, 18, 19 and Clare-Bishop of the unanesthetized cat. In contrast to squirrel monkeys and macaques in which about 40 or 25% of the units in striate cortex are luxotonic (response to continuous light or darkness sustained〉2.0 min), all of the visual areas in the cat had fewer than 4.0% of the units exhibiting such luxotonic activity. The functional basis of this difference may be related to differences between the two species in the quantitative balance of antagonistic receptive field properties.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237544
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  • 8
    Electronic Resource
    Electronic Resource
    Low threshold afferent projections from the oral cavity and the face to the cerebral cortex of the cat (1980)
    Springer
    Experimental brain research 39 (1980), S. 133-147 
    Details
    ISSN: 1432-1106
    Keywords: Cat ; Somatosensory cortex ; Oral projections ; Face projections ; Cytoarchitectonic organization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The projections of low threshold afferents from the oral cavity and the face to the cerebral cortex of cats anaesthetized with chloralose were investigated. The projection fields of the ipsi- and contralateral lingual, inferior alveolar, mental, superior alveolar, infraorbital, (separate branches from whiskers and nose), ophthalmic, great auricular and the contralateral superficial radial nerves were localized. Surface potentials of short latency and maximal amplitude were recorded and their location traced on photographs of the rostral part of the right cerebral hemisphere. Reference points were indicated with india ink punctures. The extent of the cytoarchitectonic areas was determined on histological serial sections and the borders transferred to the photographs of the hemisphere. The features of the projections were related to the cytoarchitecture and to the pattern of the gyri and sulci. It was observed that the low threshold afferents from the oral cavity and the face projected via fast conducting, presumably three synaptic paths, to separate locations in areas 3a, 3b, 5a and 6aβ. The projections to area 3b were somatotopically organized starting with the auricular and the ophthalmic nerve projections lateral to the 3b projection of the forelimb in the posterior sigmoid gyrus and continuing with the maxillary nose, maxillary whiskers, mental nerve, superior alveolar, inferior alveolar and lingual nerve fields along the coronal gyrus towards the presylvian sulcus. The somatotopy was, however, not isomorphic with the body surface but displayed consecutive, overlapping bands across area 3b. The projections to area 3a were similarly organized. The somatotopy was less obvious in area 5a and 6aβ. Convergent projections with responses of slightly longer latency were observed in area 43 (gyrus orbitalis).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237545
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  • 9
    Electronic Resource
    Electronic Resource
    The effect of electrical stimulation in the hypothalamus on the monosynaptic jaw closing and the disynaptic jaw opening reflexes in the cat (1980)
    Springer
    Experimental brain research 39 (1980), S. 389-400 
    Details
    ISSN: 1432-1106
    Keywords: Cat ; Jaw reflexes ; Hypothalamus ; Aggression ; Bruxisrn
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of electrical stimulation in the hypothalamus on the monosynaptic jaw closing and the disynaptic jaw opening reflexes were investigated in cats anaesthetized with chloralose. The hypothalamic electrodes were located by observation of behavioural attack responses in the unanaesthetized animal and by means of Horsley-Clarke coordinates. The locations were verified in histological serial sections. Hypothalamic conditioning with trains of 3–10 pulses, 0.5 ms duration, 0.5 mA, 500 Hz, evoked a strong facilitation of the jaw closing reflex and a facilitation followed by an inhibition of the jaw opening reflex. These effects differed from those elicited from the cerebral cortex. The hypothalamic effects had a longer latency (11–13 ms) and required a longer train of conditioning stimuli than was the case with those evoked from the cortex. Bilateral ablation of the sensorimotor cerebral cortex or lesion of the pyramids at the lower pontine level diminished but did not abolish the hypothalamic effects. They did, however, disappear after lesions including the ventral midbrain tegmentum. The stimulus positions eliciting the largest hypothalamic effects on the jaw reflexes were located in a region extending medio-laterally from the perifornical area to the entrance of the ansa lenticularis in the lateral hypothalamus. Rostro-caudally the location was found at the level of the ventromedial hypothalamic nucleus and the anterior hypothalamus just rostral to this nucleus. The region corresponds to those parts of the hypothalamus from which agonistic and feeding responses have been evoked. It is suggested that the observed hypothalamotrigeminal mechanism may exercise a tonic influence on the trigeminal motoneurones, thereby controlling the set point of the biting force. The implications of this hypothesis on the etiology of bruxism and the myofascial pain dysfunction are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00239303
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  • 10
    Electronic Resource
    Electronic Resource
    Functional amblyopia in kittens with unilateral exotropia (1980)
    Springer
    Experimental brain research 40 (1980), S. 294-304 
    Details
    ISSN: 1432-1106
    Keywords: Squint amblyopia ; Visual cortex ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In two cats in which surgically induced, unilateral divergent strabismus had led to behaviourally determined amblyopia, a variety of electrophysiological parameters were determined in search of neuronal correlates of squint amblyopia. Tests that assess global neuronal excitability along the pathways from the two eyes to the visual cortex (areas 17 and 18) failed to reflect the functional inferiority of the squinting eye: retinographic responses and cortical evoked potentials elicited by Ganzfeld-stimulation and by stimulation of the optic nerves were identical for the two eyes. The ocular dominance distribution of neurons in area 17 showed the expected disruption of binocularity but failed to provide clear evidence for a functional inferiority of the squinting eye. At other levels of analysis, however, a clear difference between the two eyes was apparent: 1. Responses to optimally aligned light stimuli tended to be more sluggish and the under-representation of neurons with vertically oriented receptive fields was more pronounced in neurons driven from the deviated eye than in cells dominated by the normal one. 2. Interocular inhibition as assessed from electrically evoked potentials was found to be asymmetric; responses evoked from the amblyopic eye were suppressed more readily and over longer periods by conditioning shocks applied to the normal nerve than vice versa. 3. Numerous abnormalities reflecting the functional inferiority of the squinting eye became apparent in cortical potentials evoked by phase reversal of gratings of variable spatial frequency and contrast. A laminar analysis of these field potentials suggests impaired transmission along the intracortical pathways which relay activity to supragranular layers as a major cause for abnormal responses from the squinting eye. It is concluded that squint amblyopia is associated with a variety of neuronal changes at various levels of the visual system, the present data providing evidence for alterations at the cortical level.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237794
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  • 11
    Electronic Resource
    Electronic Resource
    Effect of amphetamine and pentobarbital on sleep-wake patterns of cats with basal forebrain lesions (1980)
    Springer
    Psychopharmacology 68 (1980), S. 179-184 
    Details
    ISSN: 1432-2072
    Keywords: Amphetamine ; Pentobarbital ; Sleepwake ; EEG ; REM sleep ; Forebrain ; Cat ; Lesion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effects of amphetamine and pentobarbital upon electrographic state were studied in naive cats and cats with forebrain lesions that induce insomnia. Amphetamine increased alertness and decreased both slow wave sleep (SWS) and rapid eye movement (REM) sleep states for up to 12 h in both intact animals and cats with lesions. Pentobarbital inhibited REM sleep and alert states while increasing SWS and drowsy states in naive cats. The effect was mainly restricted to the first 8 h. In cats with forebrain lesions, the effects were similar except that the amount of REM sleep was significantly elevated. During a portion of the first 8 h, the tracing cannot be distinguished from a normal control sample. It is hypothesized that pentobarbital mimics the normal inhibitory influence of the intact forebrain and either induces or facilitates ‘normal’ sleep patterns in cats with forebrain lesions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00432138
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  • 12
    Electronic Resource
    Electronic Resource
    The tapetal cell: A unique melanocyte in the tapetum lucidum cellulosum of the cat (Felis domestica L.) (1980)
    Springer
    Anatomy and embryology 158 (1980), S. 289-302 
    Details
    ISSN: 1432-0568
    Keywords: Tapetum lucidum ; Cat ; Melanocytes ; Development ; DOPA-reaction ; DOPA ; cysteinyldopa
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The postnatal development of the tapetum lucidum cellulosum of the cat was studied with cytochemical, histochemical, microspectrofluorimetric, and chemical methods. At birth, the prospective tapetal cells exhibit a cytoplasmic, formaldehyde-induced catechol fluorescence which, by spectrographical criteria, is due to the presence of a thioether of DOPA, most likely 5-S-cysteinyldopa. These cells show a positive DOPA-reaction in the GERL, a Golgi-associated system of smooth endoplasmic reticulum. Beyond the third postnatal week, tyrosinase activity is found in the GERL and in the premelanosomal-like tapetal rods. Shortly thereafter, cells in the innermost layers of the tapetum reveal a change in the colour of the fluorophore from green (formaldehyde-induced) to orange-yellow (autofluorescent). Concomitant with the appearance of the yellow fluorophore (having spectral characteristics similar to authentic riboflavin), the DOPA-reactivity in the tapetal cells is no longer detectable and the cells attain the feature of mature tapetal elements with typical elongated, parallelly arranged, electron-dense rods. The increases and decreases in tyrosinase activity are parallelled by similar time-dependent changes in DOPA and cysteinyldopa content. Both DOPA and cysteinyldopa are considered as potential precursors of melanin polymers. Thus, these data support the concept that the tapetal cells represent uniquely differentiated and highly specialized choroidal melanocytes. The compact arrangement of these cells in the tapetum lucidum renders it an ideal tissue for studying the developmental biology of melanocytes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00301818
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  • 13
    Electronic Resource
    Electronic Resource
    The reticulocerebellar projection in the cat as studied with retrograde transport of horseradish peroxidase (1980)
    Springer
    Anatomy and embryology 160 (1980), S. 341-359 
    Details
    ISSN: 1432-0568
    Keywords: Reticulocerebellar ; Peroxidase ; Retrograde transport ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Injections of horseradish peroxidase into the various parts of the cerebellar cortex and the cerebellar nuclei in the cat result in labelled cells within the reticular formation proper. All the reticular nuclei (with the exception of the reticular formation of the mesencephalon) send fibres to the cerebellum. The highest number of labelled neurons after cerebellar injections is found in the caudal reticular formation, especially within nucleus reticularis ventralis, nucleus reticularis lateralis and nucleus reticularis gigantocellularis. Another region for an accumulation of labelled cells is the rostral part of nucleus reticularis pontis caudalis. Except for the paraflocculus, all cerebellar cortical areas and all cerebellar nuclei receive afferents from one or more of the nuclei within the reticular formation proper, but the largest number of labelled neurons is observed in cases with injections including the intermediate-lateral part of lobulus simplex and the adjacent areas of the anterior lobe and crus I. The projection is bilateral with an ipsilateral preponderance (the cerebellar nuclei appear to receive a higher number of fibres from the contralateral side). Cells of all sizes are labelled, but labelled giant cells are found only after large cortical injections.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00305113
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  • 14
    Electronic Resource
    Electronic Resource
    Mapping of monoamine neurones and fibres in the cat lower brainstem and spinal cord (1980)
    Springer
    Anatomy and embryology 161 (1980), S. 169-195 
    Details
    ISSN: 1432-0568
    Keywords: Monoamines ; Histofluorescence ; Brainstem ; Spinal cord ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The localization of monoaminergic neurones in the medulla oblongata and the pons, and the distribution of catecholaminergic fibres in the spinal cord of the cat were investigated by means of formaldehyde-induced (FIF) or glyoxylic-acid-induced (GIF) fluorescence. Four groups of catecholamine (CA)-containing neurones were found in the following regions: (1) in the ventrolateral medulla oblongata within and adjacent to the lateral reticular nucleus, beginning slightly rostral to the medullo-spinal junction and extending rostrally to the cranial third of the inferior olive; (2) in the commissural, medial and lateral nucleus of the solitary tract; (3) cranial to the first group, closely adjacent to the facial nucleus and the superior olive; and (4) in the dorsolateral pons distributed to different nuclei, namely the nucleus coeruleus and subcoeruleus, the Koelliker-Fuse nucleus, and the medial and lateral parabrachial nuclei. The indoleamine (IA)-containing cell bodies were in general confined to the raphe nuclei, namely the nucleus raphe pallidus, nucleus raphe obscurus, nucleus raphe magnus, nucleus raphe pontis, nucleus raphe dorsalis and the central superior nucleus. A few IA-neurones were located more laterally, especially dorsal and lateral of the cranial half of the inferior olive, around the root of the hypoglossal nerve, in the lateral tegmental field and the pontine central gray. In the spinal cord most CA-fibres were found in the intermediolateral cell column. Another dense accumulation of CA-fibres was located dorsally and laterally of the central canal. The ventral and dorsal horns also contained CA-nervefibres which were slightly more numerous in the sacral spinal cord than in the more rostral parts of the spinal cord.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00305343
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  • 15
    Electronic Resource
    Electronic Resource
    The cat locus coeruleus (1980)
    Springer
    Anatomy and embryology 159 (1980), S. 181-198 
    Details
    ISSN: 1432-0568
    Keywords: Cat ; Locus coeruleus ; Neuroanatomy ; Cytology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The neuronal cell bodies of the locus coeruleus (LC) and subcoeruleus (SC) of the cat were investigated using Nissl and Golgi preparations, and electron microscopy. On the basis of morphological criteria — size and shape of cell body, branching pattern of dentrites, distribution of cytoplasmic organelles and number of axosomatic synapses — four types of neuronal perikarya were recognized in each region: medium-sized, small-sized and two groups of intermediate-sized neurons. The medium-sized neurons (30–50 μm) had an elongated cell body, thick dendrites with a moderate number of branchings, abundant organelles arranged in concentric rings around the nucleus and a moderate number of axosomatic synapses. They were found throughout the LC and SC and most probably correspond to the larger class of catecholaminergic neurons demonstrated by fluorescence histochemistry. The small neurons (10–25 μm) were also seen in both LC and SC and are believed to represent non-monoaminergic local interneurons. They displayed sparsely branching dendrites and a thin rim of cytoplasm containing few organelles. In the SC, some of these small cells occurred in closely associated pairs. Ultrastructural analysis of such pairs revealed a close apposition (80–100 Å) of the cell membranes for long distances (up to 10 μm) and a narrowing of the intercellular space (30–40 Å) at some discrete points, perhaps indicative of an electrical interaction. The intermediate-sized neurons exhibited some regional morphological differences, but two distinct subgroups could be distinguished. One was characterized by a low number of axosomatic synapses, while the other exhibited a high number of such contacts. It may be assumed that the two subgroups of intermediate-sized neurons comprise catecholaminergic and indolaminergic neurons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00304977
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  • 16
    Electronic Resource
    Electronic Resource
    Profile of the sensitive period for monocular deprivation in kittens (1980)
    Springer
    Experimental brain research 39 (1980), S. 17-21 
    Details
    ISSN: 1432-1106
    Keywords: Cat ; Monocular deprivation ; Visual cortex ; Sensitive period
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Thirteen kittens were subjected to 10–12 days of unilateral eye closure at ages spaced regularly through the first 4 months after birth. At the end of each kitten's period of monocular vision, the degree of functional disconnection between the deprived eye and neurons in striate cortex was assessed by means of single-unit recording. When the proportion of cortical cells giving no response to stimulation through the deprived eye was analyzed as a function of the kitten's age at the onset of eye closure, it was found that the effectiveness of monocular deprivation rose prior to postnatal day 28, remained high through day 48 and then subsided gradually, probably persisting at least through the end of the fourth postnatal month. The degree of functional modifiability persisting in the visual cortex of older kittens may be related to the initial ocular dominance of each neuron. Cells responsive exclusively to the deprived eye prior to deprivation probably do not acquire functional input from the nondeprived eye in kittens older than 48 days, for a normal proportion of such cells is encountered after the period of eye closure. Conversely, cells dominated by the nondeprived eye probably are most likely to lose their input from the deprived eye, as indicated by the columnar organization of cells not responsive to the deprived eye.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237065
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  • 17
    Electronic Resource
    Electronic Resource
    Functional changes across the 17–18 border in the cat (1980)
    Springer
    Experimental brain research 39 (1980), S. 177-186 
    Details
    ISSN: 1432-1106
    Keywords: Visual cortex ; Cat ; Areas 17 and 18 ; Velocity sensitivity ; Magnification factor ; Vertical meridian
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Changes in velocity sensitivity, receptive field (RF) position, and RF size were investigated in long oblique penetrations crossing the 17–18 border. The penetrations were histologically reconstructed and the border determined by cytoarchitectonics. In cortex subserving central and paracentral vision change in velocity sensitivity allowed a reasonable physiological identification of the 17–18 border. The physiological border correlates well with the histological border zone, best with its medial edge. Changes in RF position and RF size are of little use for physiological identification of the border in this region. In this cortical region area 18 representation of the vertical meridian (VM) has a high magnification factor. In cortex subserving peripheral vision, the change in velocity sensitivity was small and the change in RF position coincided with the cytoarchitectonics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237548
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  • 18
    Electronic Resource
    Electronic Resource
    Facilitation and inhibition of jaw reflexes evoked by electrical stimulation of the cat's cerebral cortex (1980)
    Springer
    Experimental brain research 39 (1980), S. 149-164 
    Details
    ISSN: 1432-1106
    Keywords: Cat ; Jaw reflexes ; Cerebral cortex ; Cytoarchitectonic areas
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of electrical stimulation of the cerebral cortex on the monosynaptic jaw closing and the disynaptic jaw opening reflexes were studied in cats anaesthetized with chloralose. The time course of the reflex effects was recorded. Similar rhythmic sequences of facilitation and inhibition were observed in both reflexes (Fig. 3). The sequence could start with facilitation or inhibition. The latency of the initial effects was short (2.5 ms) indicating a minimum of two synapses in the descending path. The period of the rhythmic sequence was approximately 10 ms. Optimal parameters for the conditioning cortical stimuli were found to be: trains of 3–5 surface anodal pulses, 0.5 ms, 400 Hz. The threshold of the cortical effects on the reflexes was 0.3 mA. A single pulse evoked effects. The cortical origin of the effects was located and related to the somatosensory projections, and to the cytoarchitecture. The effects of largest amplitude and most complex time course were evoked from the oral and perioral projections to areas 3a and 3b. Effects evoked from areas 4γ, 5a, and 6aβ were less complex and of lower amplitude. It is suggested that a trigemino-cortico-trigeminal loop via 3a may function in reflex modulation of the jaw movements. In addition area 3a may contribute to cortico-cortical motor elaborations via U-fiber connections to area 4γ.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237546
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  • 19
    Electronic Resource
    Electronic Resource
    Mécanorécepteurs splanchniques de la voie biliaire et de son péritoine (1980)
    Springer
    Experimental brain research 40 (1980), S. 146-153 
    Details
    ISSN: 1432-1106
    Keywords: Microelectrode technique ; Splanchnic mechanoreceptors ; Gall bladder ; Cat ; Microélectrode mecanarecepteurs splanchniques ; Vesicule biliaire ; Chat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé Le but de ce travail est l'étude électrophysiologique des mécanorécepteurs de la vésicule biliaire. L'activité unitaire des neurones est enregistrée au moyen de microélectrodes de verre extracellulaires implantées dans les ganglions spinaux (T6-L1). Deux types de mécanorécepteurs ont été mis en évidence par stimulation punctiforme. Mécanorécepteurs musculaires a) Des récepteurs à adaptation lente localisés dans l'ensemble du tractus biliaire, sensibles à la distension. b) Des récepteurs à adaptation rapide, localisés dans la vésicule biliaire, mis en jeu par la phase dynamique de la stimulation. Ces récepteurs sont connectés avec des fibres C. Mécanorécepteurs péritonéaux a) Des corpuscules de Pacini, localisés dans le mésentère entourant le tractus biliaire. b) Des récepteurs à adaptation lente (récepteurs de mouvement), localisés dans la séreuse de la vésicule biliaire et le péritoine péricystique et péricholédocien. Les corpuscules de Pacini sont connectés avec des fibres Aβ, les récepteurs de mouvement avec des fibres Aγδ et B.
    Notes: Summary The aim of the present paper is to study the electrophysiology of splanchnic gall bladder mechanoreceptors. The neurons unitary activity is recorded by means of glass extracellular microelectrodes implanted in the spinal ganglion (T6-L1). Two types of mechanoreceptors have been revealed by punctiform stimulations. Muscular Mechanoreceptors a) Slowly-adapting receptors, located in the whole biliary tract, sensitive to distension. b) Rapidly-adapting receptors, located in the gall bladder, recruited during the dynamic phases of stimulation. These receptors connected with C fibers. Peritoneal Mechanoreceptors a) Pacinian corpuscles, located in the mesentery surrounding the biliary tract. b) Slowly-adapting receptors (movement receptors), located in the serosa of the gall bladder and the pericystic and pericholedochal peritoneum. Pacinian corpuscles are connected with Aβ fibers, movement receptors with Aγδ and B fibres.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237532
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  • 20
    Electronic Resource
    Electronic Resource
    Organization of the cortico-caudate projections (1980)
    Springer
    Experimental brain research 40 (1980), S. 203-208 
    Details
    ISSN: 1432-1106
    Keywords: Cortico-caudate neurones ; Premotor area ; Horseradish peroxidase ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The organization of the cortico-caudate projection neurones in the cerebral cortex was demonstrated by utilizing retrograde axonal transport of horseradish peroxidase (HRP) in the cat. Following injection of HRP into the head portion of the caudate nucleus, cortical labelled cells with HRP could be divided into two groups, consisting of smaller and larger pyramidal neurones. The location of the smaller neurones in the cortex was mainly in layer III, while that of the larger neurones was exclusively in layer V. In the cerebral cortex ipsilateral to the HRP-injected side, labelled cells belonging to the smaller group were distributed mostly in area 6 and occasionally in areas 4 and 5. Labelled cells belonging to the larger group were located exclusively in area 6. In the contralateral cortex, labelled cells were all smaller in size and distributed only in area 6. Referring to recent physiological as well as anatomical data, the smaller, labelled pyramidal cells were considered to be the proper, direct cortico-caudate neurones. The larger, labelled pyramidal cells were regarded as cortico-caudate projection neurones also sending axons to the lower brains tern and/or the spinal cord. The results of the present study indicate the existence of a close relationship between area 6 (premotor area) of the cerebral cortex and the caudate nucleus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237538
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  • 21
    Electronic Resource
    Electronic Resource
    Brain stem projections to the pulvinar-lateralis posterior complex of the cat (1980)
    Springer
    Experimental brain research 40 (1980), S. 209-220 
    Details
    ISSN: 1432-1106
    Keywords: Thalamus ; Visual system ; HRP ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The present experiments were undertaken to define the areas of projection of pretectum and superior colliculus to the pulvinar and n. lateralis posterior, respectively, and to define other brain stem structures projecting to these thalamic nuclei in cats. For this purpose the technique of retrograde transport of horseradish peroxidase (HRP) has been used. After injection of the enzyme in the pulvinar, neurons were labeled in all subdivisions of the pretectal area. The majority of the labeled cells were located in the n. pretectalis posterior and n. tractus opticus although cells filled with HRP were present also in the n. pretectalis anterior pars compacta and area pretectalis medialis. Neurons projecting to the pulvinar were also found in the periaqueductal gray, reticular formation and locus coeruleus. When HRP was injected in the n. lateralis posterior, labeled neurons were present in the II and III subdivisions of the second layer of the superior colliculus. The location of these cells shifted from medial to lateral as the injections were shifted from posterior to anterior within the lateralis posterior. Neurons projecting to this nucleus were also present in the intermediate layers of the superior colliculus, lateral hypothalamus and parabigeminal nucleus. The possible role of the pretectal area and superior colliculus in mediating somesthetic input to the pulvinar and lateralis posterior, respectively, and the role of these structures in the control of ocular movements, are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237539
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  • 22
    Electronic Resource
    Electronic Resource
    Cells of origin of crossed and uncrossed corticospinal fibers in the cat (1980)
    Springer
    Experimental brain research 40 (1980), S. 23-34 
    Details
    ISSN: 1432-1106
    Keywords: Pyramidal tract ; MI ; SI ; SII ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The cortical distribution of the cells of origin of the dorsolateral and the ventral corticospinal tracts was studied in cat. This was done by making subtotal spinal transections, which in different experiments spared different portions of one ventral or one lateral funiculus at C5–C7. One week later horseradish peroxidase (HRP) injections were made one segment caudal to the lesion and the cortical distribution of the HRP labeled neurons was studied. Thus, it was found that the dorsolateral corticospinal tract at C5–C7 is composed of crossed and uncrossed fibers in a ratio of about 10 ∶ 1, while the ventral corticospinal tract, which contains much fewer cortical fibers, is composed of crossed and uncrossed fibers in a ratio of approximately 1 ∶ 1. Further, the primary motor cortex (area 4) was found to contribute fibers to both the crossed and the uncrossed dorsolateral corticospinal tract as well as to both the crossed and the uncrossed ventral corticospinal tract. The primary somatosensory cortex (area 3a, 3b, 1–2, 5a, 5b) as well as the secondary somatosensory cortex (area 2 pre-insularis), on the other hand, were found to contribute fibers mainly to the crossed dorsolateral tract. Area 4 was found to display a further organization, such that it contains a medial and a lateral part, both of which contribute mainly fibers to the crossed dorsolateral tract, while the remainder of area 4 contributes fibers to the crossed and uncrossed dorsolateral as well as to the crossed and uncrossed ventral tracts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236659
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  • 23
    Electronic Resource
    Electronic Resource
    Functional amblyopia in kittens with unilateral exotropia (1980)
    Springer
    Experimental brain research 40 (1980), S. 305-310 
    Details
    ISSN: 1432-1106
    Keywords: Squint amblyopia ; Visual cortex ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In two dark reared, 40 day old kittens unilateral divergent squint was induced be resecting the insertion of the medial rectus muscle. Behavioural testing revealed that the kittens used only the normal eye for fixation. Contrast sensitivity functions of the two eyes and visual acuity were determined behaviourally in a jumping stand whereby the kittens had to discriminate sine-wave gratings or variable spatial frequency and contrast from a flux equated homogeneous field. At photopic luminance levels the deviated eye showed a significant deficit in both kittens. This impairment was apparent over the whole range of spatial frequencies (0.18–0.99 c/deg) except for the lowest spatial frequency in one kitten. The interocular difference of visual acuity disappeared at scotopic luminance levels. In subsequent electrophysiological experiments contrast sensitivity functions were determined from cortical evoked potentials that were elicited by phase reversing square wave gratings. Comparison between behavioural and electrophysiological results revealed a very good correspondence between the two sets of data. It is concluded that exotropia without alternating fixation leads to functional amblyopia of the deviated eye.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237795
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  • 24
    Electronic Resource
    Electronic Resource
    Physiological responses of cat vestibular nerve to a selective mechanical stimulation of the lateral crista ampullaris (1980)
    Springer
    Experimental brain research 40 (1980), S. 358-360 
    Details
    ISSN: 1432-1106
    Keywords: Mechanical stimulation ; Cristae ampullares ; Vestibular ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The present report describes a bidirectional mechanical stimulation technique of cristae ampullares in the cat. Bimodal field potentials are seen in the vestibular nerve and nucleus after an excitatory stimulus. This technique should allow an in vivo and selective study of the vestibular receptors in mammals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237804
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  • 25
    Electronic Resource
    Electronic Resource
    A statistical analysis and comparison of soma diameter spectra for classical neurones from different regions of the cat retinal ganglion cell layer (1980)
    Springer
    Pflügers Archiv 388 (1980), S. 239-242 
    Details
    ISSN: 1432-2013
    Keywords: Statistical model ; Cat ; Retina ; Ganglion cell layer ; Neuronal diameter spectra
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Multimodal soma diameter spectra for neurones of the cat retinal ganglion cell layer have been represented by three subpopulations of independent, normal diameter distribution. Recurrent computation according to the technique of Vibert and Caille (1978) has extracted best fit populations for samples from various regions of central and peripheral retina. The model subpopulations from all these regions did not differ significantly in their relative proportions or variance. Significant progressive variation between subpopulations representing different regions of retina were observed only in the mean diameter of the α and β mode cells. The parameters of the γ mode population were statistically uniform across the retina. The cat retina thus appears to be more homogeneously organized than has been suggested elsewhere.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00658488
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  • 26
    Electronic Resource
    Electronic Resource
    The effects of phenylmethanesulfonyl fluoride on delayed organophosphorus neuropathy (1980)
    Springer
    Archives of toxicology 46 (1980), S. 305-311 
    Details
    ISSN: 1432-0738
    Keywords: Cat ; Neurotoxic esterase ; Diisopropylfluorophosphate ; Phenylmethanesulfonyl fluoride ; Neuropathy ; Prevention
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A delayed localized neuropathy of peripheral nerves in a single hind leg of the cat develops after a single intraarterial 2 mg/kg injection of diisopropylfluorophosphate (DFP). This neuropathy is manifested by a maximum loss of the capacity of soleus α-motor nerve terminals to generate stimulus-bound repetition 21 days after DFP exposure. Phenylmethanesulfonyl fluoride (PMSF) is a protective inhibitor of the neurotoxic esterase which is associated with the development of the delayed organophosphorus neuropathy. Pretreatment of cats with PMSF (30 mg/kg i.p.) 24 h before the DFP injection protected the cats from the delayed neuropathy. No clinical neurotoxic signs were observed at 21 days after DFP. The stimulus-bound repetitive capacity of soleus α-motor nerve terminals was not lost at this time and its incidence was much greater than that which occurred in cats not pretreated with PMSF.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00310448
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  • 27
    Electronic Resource
    Electronic Resource
    Veränderungen im Sehsystem der Katze nach Netzhautläsionen (1980)
    Springer
    European archives of psychiatry and clinical neuroscience 228 (1980), S. 117-133 
    Details
    ISSN: 1433-8491
    Keywords: Afferent visual system ; Retinal lesions ; Functional neuroplasticity ; Cat ; Afferentes Sehsystem ; Netzhautläsionen ; Funktionelle Neuroplastizität ; Katze
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Bei erwachsenen Katzen wurden Schichten des Corpus geniculatum laterale (CGL) vollständig oder teilweise durch monoculäre, genau definierte Photokoagulatorläsionen der Netzhaut deafferentiert. Mit Mikroelektroden wurden Einzelneurone aus einer experimentell veränderten Schicht mit Kontrollneuronen aus einer normalinnervierten Schicht des CGL eines Versuchstieres verglichen. Nach Unterbrechung aller Afferenzen eines Auges durch Photokoagulation stieg die anfangs stark verringerte Spontanaktivität in der deafferentierten Schicht an, ohne normale Entladungsraten innerhalb von 10 Wochen wieder zu erreichen. Das Muster von Erregung und Hemmung nach Lichtreizung des nicht-dominanten, gesunden Auges hatte sich zu dieser Zeit völlig verändert. Bei begrenzten, nasalen Netzhautläsionen fanden sich beginnend etwa 27 Tage nach der Koagulation in den Randbezirken der partiellen, visuellen Deafferentierung lichterregbare Zellen mit verschobenen rezeptiven Feldern, denen eine läsionsinduzierte Erregungsausbreitung um maximal 200 μm im CGL zugrunde lag. Kleine, runde Netzhautläsionen bedingten anfänglich eine vollständige, visuelle Deafferentierung eines bestimmten CGL-Bezirks. Nach 30 und mehr Tagen wurde visuelle Erregung aus der normal innervierten Umgebung an Zellen gefunden, die in den ersten Tagen nach der Koagulation unerregbar waren. So wurde bei unveränderter Größe der retinalen Läsion ihre Repräsentation im CGL deutlich verkleinert. Die Befunde weisen im subcorticalen visuellen System der erwachsenen Katze auf läsionsinduzierte Reorganisation hin, die das System zu einer gewissen Kompensation nach Verlust visueller Eingänge befähigen könnte. Eine Übertragbarkeit der Befunde auf die Humanpathophysiologie wird kritisch diskutiert.
    Notes: Summary Layers of the lateral geniculate nucleus (LGN) of mature cats were completely or partially deafferentated by precisely defined photocoagulation of the retina. Single neuron recordings were performed with microelectrodes from an experimentally modified layer and compared with neurons from a normally innervated layer in the same animal. The spontaneous activity of cells after monocular deafferentation was severely reduced in the beginning and increased subsequently without reaching normal values within ten weeks. At this time the pattern of excitation and inhibition after light stimulation of the nondominant unsevered eye had completely changed. Twenty-seven days and later after coagulation of a part of the nasal retina light-excitable cells with displaced receptive fields were found in the LGN in the border region of the partial visual deafferentation. This indicated a lesion-induced lateral expansion of excitation by up to 200 μm within the LGN. Small, round retinal lesions initially caused a complete visual deafferentation of a certain region in the LGN. After 30 days and later visual excitation from the normally innervated surrounding was observed in cells which were not light-excitable during the first days after coagulation. Thus, while the retinal lesion itself did not substantially change, its representation within the LGN was distinctly reduced. The results indicate lesion-induced reorganization in the subcortical visual system of the adult cat. This might enable the system to a certain degree of compensation after loss of visual inputs. The transferability of these results to human pathophysiology has to be critically considered.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00365600
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  • 28
    Electronic Resource
    Electronic Resource
    Dopamine-induced diuresis in the cat without changes in renal hemodynamics (1980)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 312 (1980), S. 77-83 
    Details
    ISSN: 1432-1912
    Keywords: Dopamine ; Diuresis ; Renal blood flow ; Sympathetic activity ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of intravenous (i.v.) and intraarterial (i.a.) injection and infusion of dopamine (DA) on renal hemodynamics, regional sympathetic activity and kidney function were investigated in anaesthetized cats. In response to the i.v. bolus injection of DA (25 μg/kg), mean arterial blood pressure (MABP) was increased by 19.7%, renal blood flow (RBF) by 16.6%, and regional sympathetic discharges were inhibited. The principal effect of i.a. bolus injection of DA into the renal artery was vasoconstriction. Vasodilation was observed neither after lower doses of DA nor after pretreatment with phenoxybenzamine. During continuous i.v. infusion of 10 μg DA kg−1 min−1 MABP, RBF, renal sympathetic discharges and glomerular filtration rate (GFR) did not change, whereas urine volume was increased by 120.5%, sodium excretion by 99.7%, chloride excretion by 143.2%, and potassium excretion by 31.9%. Urine osmolality was decreased and osmolal clearance increased. Raising the DA dose to 25 μg kg−1 min−1 resulted in a fall of GFR, but the diuretic response was not significantly different from that of the low dose. Bulbocapnine (6 mg/kg i.v.) antagonized the DA-induced diuresis. In conclusion, the diuretic effect of DA in the cat is not dependent on a change in RBF, GFR or renal sympathetic activity. This suggests that a tubular site of action is primarily responsible for DA diuresis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00502578
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  • 29
    Electronic Resource
    Electronic Resource
    Central blood pressure effects of guanylyl-imido-diphosphate and cyclic guanosine-monophosphate (1980)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 312 (1980), S. 31-35 
    Details
    ISSN: 1432-1912
    Keywords: Central blood pressure control ; Cat ; Guanylyl-imido-diphosphate ; Cyclic guanosine monophosphate ; Intracerebroventricular administration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Injections of guanylyl-imido-diphosphate (250, 500 and 1,000 μg/kg) into the lateral cerebral ventricle of the anaesthetized cat induced increases in blood pressure and heart rate while the intravenous injections of the same doses were ineffective, thus indicating a central mechanism of action of this compound which activates adenylcyclase at the catalytic subunit. The results support the hypothesis that the activity of cardiovascular centres depends on the prevailing concentration of cAMP. Intracerebroventricular injection of cGMP (125, 250 and 500 μg/kg) caused hypotension and bradycardia. The effects increased with the dose but were subject to tachyphylaxis. The lack of an effect after intravenous administration indicates a central site of action. This result is in agreement with the Yin Yang hypothesis and suggests that cGMP is a second transmitter in cardiovascular centres which may be involved in central cardiovascular effects in response to stimulation by putative neurotransmitter substances such as acetylcholine.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00502571
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  • 30
    Electronic Resource
    Electronic Resource
    Hereditary deafness in the cat: An electron-microscopic study of the tectorial membrane (1980)
    Springer
    European archives of oto-rhino-laryngology and head & neck 229 (1980), S. 55-68 
    Details
    ISSN: 1434-4726
    Keywords: Erbliche Taubheit ; Katze ; Elektronenmikroskop ; Membrana tectoria ; Hereditary deafness ; Cat ; Electron microscopy ; Tectorial membrane
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary The tectorial membrane is affected at an early stage of the cochlear degeneration in the hereditarily deaf white cat. The membrane first descends towards the organ of Corti with obliteration of the intervening sub-tectorial space in the basal coil during the second post-natal week. Both the microvilli of supporting and Hensen's cells, and the hair cell stereocilia make deep indentations on the under-surface of the membrane. Cells are found insinuated between the tectorial membrane and Corti's organ, and numerous cellular processes occur within the former. A phagocytic function would appear probable for these cells, which seem to originate from the internal sulcus region. The membrane is retracted into the latter around the 2-month stage. At all ages, small spherical structures, which may represent altered interdental cell secretions, are found within the membrane, these becoming calcified in older animals.
    Notes: Zusammenfassung Veränderungen in der Membrana tectoria treten in einer frühen Phase der cochlearen Degeneration bei der weißen Katze mit erblicher Taubheit auf. Die Membran bewegt sich erst gegen das Cortische Organ mit Obliteration des dazwischenliegenden subtectorialen Raumes in der zweiten postnatalen Woche. Sowohl die Mikrovilli der Hensenschen Zellen und die der Stützzellen als die Stereozilien der Haarzellen machen tiefe Eindrücke auf der Unterseite der Membran. Zellen sind zwischen Membrana tectoria und dem Cortischen Organ gefunden, und viele zellulare Prozesse entstehen innerhalb Membrana tectoria. Eine phagocytotische Funktion würde für diese Zellen möglich sein, die aus der Region des Sulcus internus zu stammen scheinen. Bei älteren Tieren ist die Membran gegen den Sulcus internus retraktiert. Für alle Altersstufen findet man kleine spherischen Strukturen, die veränderte interdentale Zellensekrete vertreten können. Diese Strukturen werden innerhalb der Membran gefunden, und sind bei älteren Tieren verkalkt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00453752
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  • 31
    Electronic Resource
    Electronic Resource
    2,2-Disubstituierte 1,3-Dithiane aus β-Dicarbonylverbindungen (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 800-805 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 2,2-Disubstituted 1,3-Dithianes from β-Dicarbonyl Compounds1,3-Dicarbonyl compounds 2 can be condensed with 1,3-propanedithiol (1) to yield 2,2-disubstituted 1,3-dithianes 3 which are remarkably stable in contrast to analogous open-chain thioacetals 6. Compounds with alkoxycarbonyl functions are easily hydrolysed to the corresponding carboxylic acids 11 which by further esterification with alkanols 12 yield estermodified 1,3-dithianes 3. All new compounds are characterized by 13C NMR spectroscopy.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130238
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  • 32
    Electronic Resource
    Electronic Resource
    Perchlor-2-methylen-2H-pyran (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 806-807 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Perchloro-2-methylene-2H-pyranThe synthesis of the title compound 4 is described. 4 is thermally and chemically very stable.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130239
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  • 33
    Electronic Resource
    Electronic Resource
    Anchimer beschleunigte Homolysen, V. Thermische und Fluoridionen-katalysierte Umlagerungen von Benzyl)-[9-(trimethylgermyl)-9-fluorenyl]-ether (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 808-810 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Anchimerically Enhanced Homolyses, V. Fluoride Ion Catalysed Rearrangements of Benzyl 9-(Trimethylgermyl)-9-fluorenyl EtherThe thermal rearrangement (homolysis) of the germanium compound 1d into 4d is considerably slower than that of the analogous Si compound 1c. Thus, a correlation is suggested between the velocity of the rearrangement and the strength of the new bond to oxygen. The rearrangement 1d→4d is also induced by fluoride ions at room temperature.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130240
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  • 34
    Electronic Resource
    Electronic Resource
    Masthead (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980) 
    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.19801130301
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  • 35
    Electronic Resource
    Electronic Resource
    Thion- und Dithioester, XXII. α,β-Ungesättigte Thion- und Dithioester (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 919-933 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thiono and Dithio Esters, XXII. α,β-Unsaturated Thiono and Dithio Estersα,β-Unsaturated thiono and dithio esters such as O-ethyl thiocinnamate (3), methyl dithiocinnamate (7), O-ethyl thiocrotonate (17), and O,O-diethyl dithiofumarate (28) have been prepared by thiolysis between 20 and -75°C from the corresponding O- or S-alkylated tertiary amides or thioamides. They tend to dimerize in part by [4 + 2] cycloadditions. Methyl dithiocrotonate (24) could only be isolated as the endo-dimer 25.
    Notes: α,β-Ungesättigte Thion- und Dithioester wie Thiozimtsäure-O-ethylester (3), Dithiozimtsäure-methylester (7), Thiocrotonsäure-O-ethylester (17) und Dithiofumarsäure-O,O-diethylester (28) sind durch Thiolyse aus den entsprechenden O- oder S-alkylierten tertiären Amiden oder Thio-amiden bei Temperaturen von 20 bis -75°C zugänglich. Sie dimerisieren zum Teil in [4 + 2]-Cycloadditionen. Dithiocrotonsäure-methylester (24) ist nur als endo-Dimeres 25 erhältlich.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19801130312
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  • 36
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    Zur Thermolyse von Verbindungen mit geometrisch fixierter Vinyloxiran-Einheit: Stereospezifische Synthese von 4,5-anellierten cis- und trans-2,3-Dihydrofuranen (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 875-901 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thermolysis of Compounds with a Geometrically Fixed Vinyloxirane Unit: Stereospecific Synthesis of 4,5-Fused cis-and trans-2,3-DihydrofuransThe conformationally fixed vinyloxiranes 7c - f, 8a - f, and 9b - d are transformed thermally into the bicyclic ethers 23 - 25. Starting with the spiro-derivatives c - f, which are monosubstituted at the vinyl group, the ring expansion takes place with high stereospecificity leading to 4,5-fused cis-(c/e) and trans-2,3-dihydrofurans (d/f), respectively. On heating 8b and 9b in the presence of dimethylfumarate besides the isomerisation to 24b/25b two cycloadducts are formed in each case to which the structures of 29/31 and 30/32 have been assigned. Oxapentadienyl dipoles (3) are proposed as intermediates in which the rotation of C/O-bonds is energetically more favorable than rotation of C/C-bonds. The activation parameters for the transformation 8b → 24b are determined and discussed together with the reported data of some analogous ring expansion reactions.
    Notes: Die konformativ fixierten Vinyloxirane 7c - f, 8a - f und 9b - d wandeln sich thermisch mit Ausbeuten zwischen 50 und 80% in die bicyclischen Ether 23 - 25 um. Ausgehend von den an der Vinylgruppe monosubstituierten Spiro-Derivaten c - f erfolgt die Ringerweiterungsreaktion mit hoher Stereospezifität zu 4,5-anellierten cis- (c/e) bzw. trans-2,3-Dihydrofuranen (d/f). Beim Erhitzen von 8b und 9b in Gegenwart von Fumarsäuredimethylester entstehen neben den Isomeren 24b bzw. 25b jeweils zwei Cycloaddukte im Verhältnis 10: 1, denen die Strukturen 29/31 und 30/32 zugeordnet werden. Als Zwischenstufen werden Oxapentadienyl-Dipole (3) angenommen, in welchen die Rotation um C/O-Bindungen energetisch günstiger ist als die um C/C-Bindungen. Die Aktivierungsparameter der Umwandlung 8b → 24b werden bestimmt und im Zusammenhang mit denen einiger analoger Ringerweiterungen diskutiert.
    Additional Material: 12 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19801130309
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  • 37
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    Electronic Resource
    Statistische Synthesen von Rotaxanen (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 941-954 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Statistical Syntheses of RotaxanesThe acetalisation of the 28-membered cyclic diols 11a, b with the long-chain dibromo ketone 12 gives acetals 13a, b. These compounds react with triphenylmethyllithium to give 17a, b and 18a, b from which the rotaxanes 20a, b are obtained in 0.066 or 0.18 and 0.12% yield, respectively, after hydrolysis of the acetal bonds. The reacetalisation of rotaxane 20b affords, by an intraannular reaction, the prerotaxane 18b in pure form.
    Notes: Die Acetalisierung der 28-gliedrigen cyclischen Diole 11a, b mit dem langkettigen Dibromketon 12 ergibt die Acetale 13a, b. Nach Umsetzung mit Triphenylmethyllithium zu 17a, b und 18a, b werden nach Hydrolyse der Acetalbindungen die Rotaxane 20a, b in Ausbeuten von 0.066 und 0.18 bzw. 0.12% als farblose Öle isoliert. Durch Reacetalisierung von 20b wird in einer intraannularen Reaktion das Prärotaxan 18b in reiner Form erhalten.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19801130314
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  • 38
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    Umlagerung von α-Isocyanato-N2-(arylsulfonyl)amidinen in 1-Arylsulfonyl-3-imidazolin-2-one (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 934-940 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Rearrangement of α-Isocyanato-N2-(arylsulfonyl)amidines to 1-Arylsulfonyl-3-imidazolin-2-onesThe reaction of the azirines 1 with the isocyanates 2 leads to the α-isocyanato-N2-(arylsulfonyl)-amidines 6. Starting from 1b, also considerable amounts of 7b and 8b are formed as a result of a retro-ene reaction of 6b. The heterocumulenes 6 readily rearrange with a shift of the sulfonyl group to give the heterocycles 10. The mobility of the sulfonyl residue is also obvious from the reaction of 6a with hydrogen chloride to afford tosyl chloride and 8a as well as from the reaction with amines, which, however, does not only yield the tosylamides 15, but also the ureas 13 and their secondary products 14.
    Notes: Die Reaktion der Azirine 1 mit den Isocyanaten 2 führt zu den α-Isocyanato-N2-(arylsulfonyl)-amidinen 6. Ausgehend von 1b werden auch beträchtliche Mengen 7b und 8b als Folge einer Retro-En-Reaktion von 6b gebildet. Die Heterocumulene 6 lagern sich unter Wanderung der Sulfonyl-Gruppe leicht in die Heterocyclen 10 um. Die Beweglichkeit des Sulfonyl-Rests wird auch in der Reaktion von 6a mit Chlorwasserstoff zu Tosylchlorid und 8a sowie in der Umsetzung mit Aminen deutlich, die neben Tosylamiden 15 allerdings auch Harnstoffe 13 und deren Folgeprodukte 14 liefert.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19801130313
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  • 39
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    Di-μ-(carboxylato)-bis[dicarbonyl(tri-tert-butylphosphan)-ruthenium(I)](Ru - Ru) (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 989-994 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Di-μ-(carboxylato)-bis[dicarbonyl(tri-tert-butylphosphane)ruthenium(I)](Ru - Ru)Ru3(CO)12 reacts with tri-tert-butylphosphane and formic acid, acetic acid, propionic acid, butyric acid, or stearic acid to form di-μ-(carboxylato)-bis[dicarbonyl(tri-tert-butylphosphane)-ruthenium(I)](Ru - Ru). The IR and NMR spectroscopic data are discussed.
    Notes: Ru3(CO)12 reagiert mit Tri-tert-butylphosphan und Ameisensäure. Essigsäure, Propionsäure, Buttersäure oder Stearinsäure unter Bildung von Di-μ-(carboxylato)-bis[dicarbonyl(tri-tert-butylphosphan)ruthenium(I)](Ru - Ru). Die IR- und NMR-spektroskopischen Daten der neuen Komplexe werden diskutiert.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130318
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  • 40
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    Addition von Aldehyden an aktivierte Doppelbindungen, XXIII. Synthesen von 1,3,6-Triketonen (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 979-988 
    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, XXIII. Syntheses of 1,3,6-TriketonesThiazolium salt-catalyzed addition of aldehydes to monoacetals of vinyl-1,3-diketones (1, 2; 23, 24) leads to 1,4-diketones (3 - 10; 25 - 31), which are hydrolyzed to 1,3,6-triketones (11 - 18; 32 - 38). A way to the mono-acetalized vinyl-1,3-diketones 1, 2; 23, 24 using the norbornenyl group with following pyrolysis is given.
    Notes: Thiazoliumsalz-katalysierte Additionen von Aldehyden an mono-acetalisierte Vinyl-1,3-diketone (1,2; 23, 24) führen zu 1,4-Diketonen (3 - 10; 25 - 31), die sich zu den 1,3,6-Triketonen (11 - 18; 32 - 38) hydrolysieren lassen. Ein Syntheseweg zu den mono-acetalisierten Vinyl-1,3-diketonen 1, 2; 23, 24 über die Norbornenyl-Gruppierung und nachfolgende Pyrolyse wird angegeben.
    Additional Material: 6 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19801130317
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  • 41
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    Einführung der (Dimethylhydrazono)ethylgruppe in methylenaktive Verbindungen und Phenole (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 970-978 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Introduction of the (Dimethylhydrazono)ethyl Group into Methylene Active Compounds and PhenolsIn [2-(dimethylhydrazono)ethyl]trimethylammonium iodide the trimethylammonium group can be substituted by several nucleophiles. With this reagent (dimethylhydrazono)ethyl derivatives of CH-acidic compounds, phenols, and indole can be prepared.
    Notes: In [2-(Dimethylhydrazono)ethyl]trimethylammonium-iodid (19) läßt sich die Trimethylammoniumgruppe durch verschiedenartige Nucleophile verdrängen. CH-acide Verbindungen sowie Phenole und Indole kann man mit diesem Reagenz zu den entsprechenden Hydrazonoethyl-Derivaten umsetzen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130316
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  • 42
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    Synthese neuer Mono- und Disaccharidglycale zum Aufbau von Oligodesoxyoligosacchariden (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 955-969 
    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 Novel Mono- and Disaccharide Glycals for the Synthesis of Oligodeoxy OligosaccharidesUnder various conditions opening of the 6-deoxy-allo-epoxide 1 with lithium iodide yields a mixture of the 3-iodo-gluco-(3) and, predominantly, the 2-iodo-altro-hydrine (2), the reaction of which with methyllithium is studied. By a simplified procedure rendering a separation of 2a and 3a unnecessary the preparation of crystalline D-digitoxal (4a) in approximately 50% yield based on 1 is described. The condensation of 1 and 4b in the presence of N-iodosuccinimide yields the α,1→4-linked altro-allo disaccharide derivative 8a, and only minor amounts of the isomeric β,1→4-linked allo-allo disaccharide 10. Following the opening of the epoxide ring in 8a with lithium iodide and subsequent separation of the iodo hydrines by reduction of the bis-altro derivative 11a a synthesis of the methyl glycoside of the terminal disaccharide (12a) in neodigoxin is achieved. Starting with a reduction of 8a to 13b the subsequent opening of the epoxide ring with lithium iodide and separation of the isomers gives an access to the ribo-altro derivative 16b. By its reaction with methyllithium the disaccharide glycal digitoxosyl-digitoxal 15a is synthesized. The linkage of 15b with 1 is effected by application of the N-iodosuccinimide procedure and yields the trisaccharide derivative 17. The structures and conformations of all derivatives are characterized by comprehensive 1H NMR spectroscopy.
    Notes: Die Öffnung des 6-Desoxy-allo-epoxid-Derivats 1 mit Lithiumiodid gibt unter verschiedenen Bedingungen ein Gemisch aus dem 3-Iod-gluco-(3) und überwiegend dem 2-Iod-altro-Hydrin (2), deren Umsetzungen mit Methyllithium untersucht werden. Ein vereinfachtes Verfahren ermöglicht ohne Trennung von 2a und 3a die Herstellung des kristallinen D-Digitoxals (4a) mit ca. 50% Ausbeute, bezogen auf 1. Die Kondensation von 1 mit 4b und N-Iodsuccinimid gibt glatt das α,1→4-verknüpfte altro-allo-Disaccharid-Derivat 8a und nur in geringen Mengen das isomere β,1→4-gebundene allo-allo-Disaccharid 10. Nach Öffnung des Epoxidringes in 8a mit Lithiumiodid und Trennung der Iodhydrine wird durch Reduktion des bis-altro-Derivats 11a das Methylglycosid des terminalen Disaccharids (12a) aus Neodigoxin gewonnen. Durch vorgelagerte Reduktion von 8a zu 13b läßt sich nach Öffnung des Epoxidringes mit Lithiumiodid und Trennung der Isomeren aus dem ribo-altro-Derivat 16b mit Methyllithium das Disaccharidglycal Digitoxosyl-digitoxal 15a darstellen. Die Verknüpfung von 15b mit 1 nach dem N-Iodsuccinimid-Verfahren liefert das Trisaccharid-Derivat 17. Alle Derivate wurden hinsichtlich der Struktur und Konformation durch 1H-NMR-Spektren charakterisiert.
    Additional Material: 4 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19801130315
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    Übergangsmetall-Carbin-Komplexe, LII. (Tricarbonylchrom)-η;6-phenyl als Substituent in Carben- und Carbinkomplexen der VI. Nebengruppe (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 1010-1019 
    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, LII. (Tricarbonylchromium)-η6-phenyl as Substituent in Carbene- and Carbyne Complexes of the VI. SubgroupThe reaction of tricarbonyl(η6-phenyllithium)chromium with the metalhexacarbonyls of the VI. subgroup and subsequent alkylation by triethyloxonium tetrafluoroborate yields pentacarbonyl-{ethoxy[(tricarbonylchromium)-η6-phenyl]carbene} complexes of chromium, molybdenum, and tungsten (1 - 3). 1 and 3 react with boron trihalides BX3 (X = Cl, Br) by cleavage of the ethoxy group to form trans-tetracarbonylhalogeno[(tricarbonylchromium)-η6-phenylcarbyne]metal complexes 4 - 7. Properties, spectroscopic results, and the X-ray structure analysis of 6 are discussed.
    Notes: Die Umsetzung von Tricarbonyl(η6-phenyllithium)chrom mit den Metallhexacarbonylen der VI. Nebengruppe und anschließende Alkylierung mittels Triethyloxonium-tetrafluoroborat führt zu Pentacarbonyl{ethoxy[(tricarbonylchrom)-η6-phenyl]carben}-Verbindungen des Chroms, Molybdäns und Wolframs (1 - 3). 1 und 3 reagieren mit den Bortrihalogeniden BX3 (X = Cl, Br) unter Abspaltung der Ethoxygruppe zu den trans-Tetracarbonylhalogeno[(tricarbonylchrom)-η6-phenylcarbin]metall-Komplexen 4 - 7. Eigenschaften und spektroskopische Ergebnisse sowie die Röntgenstrukturanalyse von 6 werden diskutiert.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130320
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  • 44
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    Beiträge zur Chlorierung - Dehydrochlorierung von Perhydro-1,4-thiazepin-5-onen (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 995-1009 
    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 Chlorination - Dehydrochlorination of Perhydro-1,4-thiazepin-5-onesThe synthesis of unsaturated derivatives of perhydro-1,4-thiazepin-5-ones 3 is investigated. Depending on the substitution the thiazepin-5-ones 3 thereby react with sulfuryl chloride to yield 7- and 2-chloro derivatives 6 and 7; the latter eliminate hydrogen chloride only in the presence of a base (PVP, 8) to give the Δ2-thiazepines 9a,b,d,e,g, whereas the 7-chloro derivatives in situ afford the Δ6-thiazepines 10a - f, the 1,4-thiazepinium chloride 11c being isolated as intermediate. tert-Butyl hypochlorite forms according to the substituent size and solvent polarity 2- and 7-halogenation products, as well as 1,4-thiazepin-5-one-S-oxides 22. Further halogenation of the Δ6-1,4-thiazepines 10a - c results in the formation of unsaturated halogen derivatives 24, 25, and 26.
    Notes: Es wird versucht, ungesättigte Derivate von Perhydro-1,4-thiazepin-5-onen 3 herzustellen. Die Thiazepin-5-one 3 reagieren dabei je nach Substitution mit Sulfurylchlorid zu 7- und 2-Chlorderivaten 6 und 7; letztere eliminieren Chlorwasserstoff erst in Basen-Gegenwart (PVP, 8) zu den Δ2-Thiazepinen 9a,b,d,e,g, die 7-Chlorderivate dagegen in situ zu den Δ6-Thiazepinen 10a - f, wobei das 1,4-Thiazepinium-chlorid 11c in Substanz erhalten wird. tert-Butylhypochlorit ergibt je nach Substituentengröße und Solvenspolarität neben 2- und 7-Halogenierung auch durch Umlagerung 1,4-Thiazepin-5-on-S-oxide 22. Erneute Halogenierung der Δ6-1,4-Thiazepine 10a - c ergibt die ungesättigten Halogenderivate 24, 25 und 26.
    Additional Material: 3 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19801130319
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  • 45
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    Zur Kenntnis organischer Lewis-Säuren, 34. Die thermische [4π + 2π]-Cycloaddition von Enolethern an 1,1-dicarbonylsubstituierte Ethene (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 1020-1032 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Organic Lewis Acids, 341. Thermal [4π + 2π]-Cycloaddition of Enol Ethers to 1,1-Dicarbonyl Substituted EthenesEnol ethers such as ethyl vinyl ether and 1,1-dimethoxyethene (3f) react thermally, in some instances below 0°C, with cyclic 2-alkylidene-1,3-dicarbonyl compounds such as 1 and 2 to give [4π + 2π]-cycloadducts 4 and 5, respectively (cyclic enol acetals and enol orthoesters), and with 1,1-dicyanoethenes 6 to give [2π + 2π]-cycloadducts 7. On passing from toluene to acetonitrile as the solvent, rates of formation of 4bf from 1b and 3f increase about tenfold and those of 7b from 6b and 3f about sixfold. A discussion of these rates, including rates of related reactions, the relative Lewis acid strengths of 1b and 6b, and the behaviour of 1b/3f towards methanol leads to the conclusion that the degree of concert of the formation of 4bf is below 6.5 kJ · mol-1. - The configurations and conformations of adducts 4 and 5 are discussed.
    Notes: Enolether wie Ethylvinylether und 1,1-Dimethoxyethen (3f) bilden mit exocyclisch 1,1-dicarbonylsubstituierten Ethenen wie 1 und 2 z.T. schon unterhalb von 0°C thermisch die [4π + 2π]-Addukte 4 bzw. 5 (cyclische Enolacetale und Enolorthoester) und mit den 1,1-Dicyanethenen 6 die [2π + 2π]-Addukte 7. Die Bildungsgeschwindigkeit von 4bf aus 1b und 3f steigt auf etwa das Zehnfache und die von 7b aus 6b und 3f auf etwa das Sechsfache beim Übergang von Toluol auf Acetonitril als Lösungsmittel. Eine Diskussion dieser Bildungsgeschwindigkeiten unter Einbeziehung verwandter Reaktionsgeschwindigkeiten sowie der relativen Lewis-Säurestärken von 1b und 6b und des Verhaltens des Systems 1b/3f gegenüber Methanol führt zum Schluß, daß der energetische Konzertiertheitsgrad der Bildung von 4bf unter 6.5 kJ · mol-1 liegt. Die Konfigurationen und Konformationen der Addukte 4 und 5 werden diskutiert.
    Additional Material: 3 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19801130321
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    Stereochemie aliphatischer Carbokationen, 13. Protonierte Cyclopropane als Zwischenstufen von 1,2-Alkylverschiebungen (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 129-141 
    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 Aliphatic Carbocations, 13. Protonated Cyclopropanes as Intermediates in 1,2-Alkyl ShiftsThe nitrous acid deamination of 2-ethyl-1-methylbutylamine (10), 1,2-diethylbutylamine (35), and 2-ethyl-1-methylpentylamine (43) has been studied with respect to 1,2-alkyl shifts. Optically active and deuterated amines were employed whenever possible. The structure, configuration, and deuterium distribution of various products (e.g. 16 from 10, 40 and 48 from 35, 56 from 43) are most reasonably explained in terms of alkyl-bridged intermediates (corner-protonated cyclopropanes) which isomerize via proton shifts from corner to corner. The alternative interconversion of open ions via 1,3-H shifts is incompatible with our experimental results.
    Notes: Die Desaminierung von 2-Ethyl-1-methylbutylamin (10), 1,2-Diethylbutylamin (35) und 2-Ethyl-1-methylpentylamin (43) mit salpetriger Säure wurde im Hinblick auf 1,2-Alkylverschiebungen untersucht. Soweit möglich wurden optisch aktive und deuterium-markierte Amine eingesetzt. Die Struktur, Konfiguration und Deuterium-Verteilung verschiedener Produkte (z.B. 16 aus 10, 40 und 48 aus 35, 56 aus 43) wird am besten erklärt mit Hilfe alkylverbrückter Zwischenstufen (eckenprotonierter Cyclopropane), die durch Protonenverschiebung von Ecke zu Ecke isomerisieren. Die alternative Umwandlung offener Kationen durch 1,3-H-Verschiebung ist mit unseren experimentellen Ergebnissen unvereinbar.
    Additional Material: 3 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19801130114
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    Kristall- und Molekülstrukturen des S3N2+-Radikalkations in S3N2+SO3CF3- · 1/2 CH3CN und von S3N2(NSO2F) (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 226-232 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Crystal and Molecular Structures of the S3N2+ Radical Cation in S3N2+SO3CF3- · 1/2 CH3CN and of S3N2(NSO2F)The molecular and crystal structures of S3N2+SO3CF3- · 1/2 CH3CN (1) and S3N2NSO2F (2) were determined from single crystal X-ray diffraction data. The S3N2+ radical cation in 1 is planar, two cations being connected through weak S—S bonding interactions to form dimers with a chair configuration. The S3N2 ring of 2, in which the NSO2F group is covalently bonded to one of the S atoms of the S — S group, is not planar; the S — S bond is weaker than in 1.
    Notes: Die Röntgenstrukturanalysen von S3N2+SO3CF3- - 1/2 CH3CN (1) und S3N2NSO2F (2) zeigen in 1 ein planares S3N2+-Radikalkation, wobei zwei Kationen über schwache S-S-Wechselwirkungen zu sesselförmigen Dimeren assoziiert sind. Der an einem S-Atom der S — S-Gruppe substituierte S3N2-Ring in 2 ist nicht planar; die S — S-Bindung ist schwächer als in 1.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19801130123
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    Kinetische und mechanistische Untersuchungen von Übergangsmetallkomplex-Reaktionen, IV. Reaktionen von Komplexliganden, XVIII. Kinetik und Mechanismus der Einschiebung von 1-(Diethylamino)-1-propin in die Metall-Carbenkohlenstoff-Bindung von Pentacarbonyl(arylmethoxycarben)chrom(O) und -wolfram(O) (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 193-202 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Kinetic and Mechanistic Investigations of Transition Metal Complex Reactions, IV. Reactions of Complex Ligands, XVIII. Kinetic and Mechanism of the Insertion of 1-(Diethylamino)-1-propyne into the Metal-Carbene Bond of Pentacarbonyl(arylmethoxycarbene)chromium(0) and -tungsten(0)Pentacarbonyl(arylmethoxycarbene) complexes (CO)5M[C(p-C6H4R)OCH3] (M = Cr, W; R = CF3, Br, H, CH3, OCH3) (1a - g) add 1-(diethylamino)-1-propyne (2) via insertion of the alkyne into the metal-carbene bond. The formation of pentacarbonyl[(diethylamino)(2-aryl-2-methoxy-1-methylethenyl)carbene]chromium(0) and -tungsten(0) (3a - g) in octane follows a second-order rate law: d[3]/dt = k[1][2]. The tungsten complexes react faster than the analogous chromium compounds. Replacement of R = H by electron withdrawing substituents (CF3, Br) results in an increase, by electron donating groups (CH3, OCH3) in a decrease of the reaction rate. The activation enthalpies ΔH≠ are low (25.1 - 39.4 kJ · mol-1), the activation entropies ΔS≠ strongly negative (-129 to -145 J · mol- K-1). The results are discussed on the basis of an associative stepwise mechanism with an attack of the ynamine at the carbene carbon in the first reaction step.
    Notes: Pentacarbonyl(arylmethoxycarben)-Komplexe (CO)5M[C(p-C6H4R)OCH3] (M = Cr, W; R = CF3, Br, H, CH3, OCH3) (1a - g) addieren 1-(Diethylamino)-1-propin (2) unter Einschiebung des Alkins in die Metall-Carbenkohlenstoff-Bindung. Die Bildung von Pentacarbonyl[(diethylamino)(2-aryl-2-methoxy-1-methylethenyl)carben]chrom(0) und -wolfram(0) (3a - g) in Octan erfolgt nach einem Geschwindigkeitsgesetz zweiter Ordnung: d[3]/dt = k[1][2]. Die Wolframkomplexe reagieren schneller als die entsprechenden Chromverbindungen. Ersatz von R = H durch elektronenziehende Substituenten (Br, CF3) führt zu einer Erhöhung, durch elektronenspendende Gruppen (CH3, OCH3) zu einer Verringerung der Reaktionsgeschwindigkeit. Die Aktivierungsenthalpien ΔH≠ sind niedrig (25.1 - 39.4 kJ · mol-1), die Aktivierungsentropien ΔS≠ stark negativ (-129 bis -145 Jmol-1 K-1). Die Ergebnisse werden auf der Grundlage eines mehrstufigen Mechanismus mit einem Angriff des Inamins am Carbenkohlenstoff im ersten Reaktionsschritt diskutiert.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19801130120
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    Sugar enolones, XII. Peroxidation of pyranose-derived enol esters: An efficacious synthesis of peracetylhexosuloses and their conversion into γ-pyrones via 3,2-enolones (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 489-510 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zucker-enolone, XII. Peroxidation pyranoider Enolester: Eine ergiebige Synthese von Peracetyl-hexosulosen und ihre Umwandlung in γ-Pyrone über 3,2-EnoloneVon Pyranosen abgeleitete 1,2-Enolacetate des Typs 4 reagieren mit 3-Chlorperbenzoesäure in Ether glatt zu einem Gemisch anomerer Glycos-2-ulose-acetate 6, wie anhand der Umwandlungen 7 → 11/12, 18 → 19/20 und 21 → 22 gezeigt wird. Konstitution und Konfiguration der Produkte stützen sich auf NMR-Daten, auf die Charakterisierung von Hydrierungsprodukten (10 bzw. 23) sowie im Falle von 11, 12 und 22 auf deren Bildung aus den entsprechenden partiell acetylierten Pyranosen 8, 9 und 23 durch RuO4-Oxidation. - Saure Acetylierung überführt die Glycos-2-ulosen in ihre 2,2-Diacetoxy-Derivate (13, 24 bzw. 35) unter Anomerisierung der β-Isomeren; bei vorsichtiger Behandlung mit Acetylchlorid/Pyridin werden dagegen, unter Erhalt der Konfiguration an C-1, die peracetylierten 2,3-Dehydro-pyranosen 15, 17 und 36 erhalten. Unter schwach basischen Bedingungen erfolgt die Ausbildung des γ-Pyron-Systems (42/43) durch doppelte Eliminierung von Essigsäure, wobei die Zwischenprodukte isolierbar sind und als die 3,2-Enolone 37α, 37β und 38 charakterisiert werden können. Hierbei konnte das aus der Tetraacetyl-glucose 44 durch Oxidation leicht darstellbare Triacetyl-endiolon 41, das Zwischenprodukt des Übergangs 11 → 42 sein soll40, als Intermediat ausgeschlossen werden.
    Notes: Pyranose-derived 1,2-enol acetates of type 4 readily react with 3-chloroperbenzoic acid in ether to an anomeric mixture of glycos-2-uloses 6, as is demonstrated by the conversions 7 → 11/12, 18 → 19/20 and 21 → 22. Structural and configurational assignments were based on NMR-data, on the characterization of hydrogenation products (10 and 23), and on the independent formation of 11, 12, and 22 by RuO4-oxidation of the respective partially acetylated pyranoses 8, 9, and 23. -Acid-catalyzed acetylation converts the glycos-2-uloses into their 2,2-diacetoxy derivatives (13, 24, and 35) with anomerization of β-isomers, whereas cautious treatment with acetyl chloride/pyridine affords the peracetylated 2,3-dehydropyranoses 15, 17, and 36 with retention of configuration at C-1. Mildly basic conditions initiate the elaboration of the γ-pyrone systems (42/43) via double elimination of acetic acid, the respective intermediates, 3,2-enolones 37α, 37β, and 38, being readily isolable. The alternate triacetyl-enediolone 41, allegedly40 an intermediate in the conversion 11 → 42 could be excluded as an intermediate on the basis of its synthesis from tetraacetyl-glucose by oxidation and elimination of acetic acid (44 → 45 → 41).
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19801130208
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    Alkine und Cumulene, XII. Über die Verwendung von Acetylendicarbonsäure-di-tert-butylester in Diels-Alder-Additionen (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 531-541 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Alkynes and Cumulenes, XII. The Application of Di-tert-butyl Acetylenedicarboxylate in Diels-Alder AdditionsDi-tert-butyl acetylenedicarboxylate (1) may be added in good yields to the model dienes 1,3-butadiene (6a), 2-methyl-1,3-butadiene (6b), 2,3-dimethyl-1,3-butadiene (6c), furan (10), and 1,3-cyclohexadiene (19) to afford the Diels-Alder adducts 7a - c, 12 (E = CO2C(CH3)3), and 20, respectively. Under certain conditions the reaction with 10 also leads to the four 2:1-adducts 13 - 16 (E = CO2C(CH3)3). Whereas the esters 7a - c are converted in quantitative yields to the corresponding anhydrides 8a - c by warming in the presence of catalytic amounts of p-toluenesulfonic acid or by heating in substance, the decomposition of 12 and 20 stops at the stage of the monoesters 17 and 21, respectively. Competition experiments show that 1 is approximately three times less reactive towards 6c than dimethyl acetylenedicarboxylate (11). It is shown that 1 is a useful dienophile for the preparation of “mixed” [2.2]paracyclophanes of type 28.
    Notes: Acetylendicarbonsäure-di-tert-butylester (1) reagiert in guten Ausbeuten mit den Modell-Dienen 1,3-Butadien (6a), 2-Methyl-1,3-butadien (6b), 2,3-Dimethyl-1,3-butadien (6c), Furan (10) und 1,3-Cyclohexadien (19) zu den Diels-Alder-Addukten 7a-c, 12 (E = CO2C(CH3)3) und 20. Im Fall von 10 gelingt unter bestimmten Bedingungen auch die Isolierung der vier 2:1-Addukte 13 - 16 (E = CO2C(CH3)3). Während die Ester 7a - c durch Erwärmen in Gegenwart katalytischer Mengen von p-Toluolsulfonsäure bzw. beim Erhitzen in Substanz quantitativ in die entsprechenden Anhydride 8a - c übergeführt werden können, bleibt diese Zersetzung für 12 und 20 auf der Stufe der Monoester 17 bzw. 21 stehen. Wie Konkurrenzexperimente zeigen, ist 1 gegenüber 6c etwa dreimal weniger reaktiv als Acetylendicarbonsäure-dimethylester (11). Es wird gezeigt, daß 1 ein nützliches Dienophil bei der Darstellung „gemischter“ [2.2]Paracyclophane vom Typ 28 ist.
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    URL: http://dx.doi.org/10.1002/cber.19801130211
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    Die Spaltung nichtgespannter CC-Einfachbindungen in Tricarbonyleisenkomplexen 5,5-dialkylsubstituierter Cyclopentadiene (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 542-554 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cleavage of Unstrained CC Single Bonds in Tricarbonyliron Complexes of 5,5-Dialkyl-substituted CyclopentadienesCleavage of CC single bonds in η4-spirononadieneiron complex 9 is initiated by Fe2(CO)9 in boiling benzene, leading to the bridged (σ-alkyl-π-cyclopentadienyl)iron complex 10. By Fe2(CO)9 the latter is transformed to the dinuclear “propylfulvene complex” 16. The observed CC bond cleavage reactions of spirocyclopentadienes 6 can also be applied to monocyclic 5,5-dialkylcyclopentadienes 1. Crossover experiments and stereochemical results suggest an intramolecular reaction path and migration of the endo-alkyl group.
    Notes: Die Spaltung einer CC-Einfachbindung im η4-Spirononadieneisen-Komplex 9 wird durch Fe2(CO)9 in siedendem Benzol initiiert und führt zum überbrückten (σ-Alkyl-π-cyclopentadienyl)eisen-Komplex 10. Dieser reagiert - wiederum unter der Einwirkung von Fe2(CO)9 - weiter zum zweikernigen „Propylfulven-Komplex“ 16. Die an Spirocyclopentadienen 6 beobachteten Umwandlungen unter CC-Bindungsspaltung lassen sich auf offenkettige 5,5-Dialkylcyclopentadiene 1 übertragen. Aus Kreuzungsversuchen und stereochemischen Befunden kann ein intramolekularer Reaktionsverlauf unter Wanderung der endo-Alkylgruppe abgeleitet werden.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19801130212
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    Einfache Synthese von 3-Acetyl-2-norbornanon durch Diels-Alder-Reaktion und Reaktivität seiner Derivate (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 555-565 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Simple Synthesis of 3-Acetyl-2-norbornanone via Diels-Alder Reaction and Reactivity of its DerivativesCyclopentadiene reacts SnCl4-catalyzed with the readily accessible benzyl ether 1b to give norbornene 2. Benzyl cleavage leads to the diol 3, on the other hand hydrogenation yields the 3-acetylnorbornanol 13 which is oxidized and methylated via 6 to 7. The acetyl group of diketone 7 reacts selectively with ylen (→ 8) and orthoformate (→ 9). With methyl lithium however the diol 12 is formed. Selective reaction of the 2-ketogroup of 2 is only possible after protecting the acetyl function in 2 (→ 5 → 14 → 10 → 19). The Grignard reaction of 2 is sterically hindered and leads with methyl or ethyl magnesium halide to 4a or b. The α,β-unsaturated ketones 16 resp. 17a and b are obtained from 4a resp. b via hydrogenation (→ 15a, b), oxidation (→ 11a, b) and dehydration.
    Notes: Cyclopentadien reagiert SnCl4-katalysiert mit dem leicht zugänglichen Benzylether 1b zum Norbornen 2. Benzylspaltung mit Natrium führt zum Diol 3, während Hydrierung das 3-Acetylnorbornanol 13 ergibt, dessen Oxidation und Methylierung über 6 zu 7 führt. Im Diketon 7 reagiert die Acetylgruppe selektiv mit Ylen (→ 8) und Orthoameisensäureester (→ 8), mit Methyllithium wird dagegen das Diol 12 gebildet. Eine selektive Reaktion der 2-Ketogruppe ist nur nach Schützen der Acetylfunktion in 2 (→ 5 → 14 → 10 → 19) möglich. Die Grignard-Reaktion von 2 ist sterisch gehindert. Sie führt mit Methyl- bzw. Ethyl-magnesiumhalogenid zu 4a bzw. b, woraus nach Hydrierung (→ 15a, b), Oxidation → 11a, b), und Wasserabspaltung die α,β-ungesättigten Ketone 16 bzw. 17a und b erhalten werden.
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    URL: http://dx.doi.org/10.1002/cber.19801130213
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    Addition von Aldehyden an aktivierte Doppelbindungen, XXII. Addition von aliphatischen Aldehyden an α,β-ungesättigte Carbonsäureester und Nitrile (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 690-698 
    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, XXII. Addition of Aliphatic Aldehydes to α,β-Unsaturated Esters and NitrilesThiazolium salt catalysed addition of aliphatic aldehydes to α,β-unsaturated esters and nitriles leads to γ-ketocarboxylic esters (1 - 24) and γ-ketonitriles (25 - 32).
    Notes: Aliphatische Aldehyde addieren thiazoliumsalz-katalysiert an α,β-ungesättigte Carbonsäureester und Nitrile unter Bildung von γ-Ketocarbonsäureestern (1 - 24) und γ-Ketosäurenitrilen (25 - 32).
    Additional Material: 2 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19801130226
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    Urofuransäuren - eine bisher unbekannte Klasse von Stoffwechselprodukten (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 699-709 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Urofuranic Acids - a Hitherto Unknown Class of Metabolic CompoundsBy a combination of chromatographic methods 1 mg of pentylurofuranic acid, a dicarboxylic acid C14H20O5, was isolated from 10 1 urine. According to spectroscopic measurements in combination with reactions in microscale its structure is 3-carboxy-4-methyl-5-pentyl-2-furanpropanoic acid (1a). This was confirmed by synthesis. Pentylurofuranic acid does not only occur in urine, but also in blood. Accompanying compounds differ only in the construction of the side chain in position 5.
    Notes: Aus 10 1 Harn wurde durch Kombination verschiedener chromatographischer Verfahren 1 mg Pentylurofuransäure, eine Dicarbonsäure C14H20O5, isoliert. Ihr kommt nach spektroskopischer Untersuchung in Kombination mit Mikroabbaureaktionen die Konstitution 3-Carboxy-4-methyl-5-pentyl-2-furanpropansäure (1a) zu, die durch Synthese gesichert wurde. Die Pentylurofuransäure kommt nicht nur im Harn (0.5-2 mg/24 h), sondern auch im Blut vor. Begleitverbindungen unterscheiden sich von ihr nur durch den Bau der Seitenkette in Stellung 5.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19801130227
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    Asymmetrische Synthesen, V. Optisch aktive 5-Amino-4-phenyl-1,3-dioxane und deren Einfluß auf die Stereoselektivität der asymmetrischen Strecker-Synthese (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 710-721 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Asymmetric Syntheses, V. Optically Active 5-Amino-4-phenyl-1,3-dioxanes and Their Influence on the Stereoselectivity of the Asymmetric Strecker-SynthesisFrom (1S, 2S)-(+)-2-amino-1-phenyl-1,3-propanediol (1) and aldehydes or ketones 2a - e, respectively, the appropriate 5-amino-4-phenyl-1,3-dioxanes 3a - e are prepared. With benzaldehyde they form well crystallizing azomethines 4a - e. The conformation and configuration of 3a - e and 4a - e are deduced spectroscopically. From these results, and from investigations of the epimer equilibria 5a - e/6a - e conclusions are drawn about the stereochemical course of the asymmetric Strecker-synthesis.
    Notes: Aus dem (1S, 2S)-(+)-2-Amino-1-phenyl-1,3-propandiol (1) werden mit den Aldehyden bzw. Ketonen 2a - e die entsprechenden 5-Amino-4-phenyl-1,3-dioxane 3a - e hergestellt, die mit Benzaldehyd die gut kristallisierenden Azomethine 4a - e bilden. Die Konformation und Konfiguration von 3a - e und 4a - e werden spektroskopisch bestimmt. Aus diesen Ergebnissen und den Untersuchungen über das Epimerengleichgewicht 5a - e/6a - e lassen sich Rückschlüsse auf den stereochemischen Verlauf der asymmetrischen Strecker-Synthese ziehen.
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    URL: http://dx.doi.org/10.1002/cber.19801130228
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    Beiträge zur Chemie des Bors, CV. (N-Lithiomethylamino)dimethylboran als Reagens zur Darstellung N-funktioneller Aminodimethylborane (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 728-738 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Chemistry of Boron, CV. (N-Lithiomethylamino)dimethylborane as a Reagent for the Preparation of N-Functional AminodimethylboranesThe reagent (CH3)2 — N(CH3)Li (1) allows the synthesis of many borylaminoelement compounds such as (CH3)2B — NCH3 — BCH3 — N(CH3)2, (CH3)2Si[NCH3 — B(CH3)2]2, (CH3)2B - NCH3 — Si(CH3)2 — NCH3 — Si(CH3)2Br, (CH3)2B — NCH3 — P(CH3)2 or (CH3)2B — NCH3 — As(CH3)2. Multifunctional element halides cause the formation of a complex mixture of products, and this is in part due to cyclocondensation reactions of longer chain compounds.
    Notes: Das Reagens (CH3)2B — N(CH3)Li (1) ermöglicht die Synthese zahlreicher Borylaminoelement-Verbindungen wie (CH3)2B — NCH3 — BCH3 — N(CH3)2, (CH3)2Si[NCH3 — B(CH3)2]2, (CH3)2B — NCH3 — Si(CH3)2 — NCH3 — Si(CH3)2Br, (CH3)2B — NCH3 — P(CH3)2 oder (CH3)2B — NCH3 — As(CH3)2. Mit mehrfunktionellen Elementhalogeniden wird die Produktpalette komplexer, was auch auf Cyclokondensation der längerkettigen Verbindungen zurückzuführen ist.
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    URL: http://dx.doi.org/10.1002/cber.19801130230
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    Neue Kondensationsreaktionen an 4-Hydroxy-3-oxo-2,5-diphenyl-2,3-dihydrothiophen-1,1-dioxid (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 750-756 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: New Condensation Reactions of 4-Hydroxy-3-oxo-2,5-diphenyl-2,3-dihydrothiophene 1,1-Dioxide4-Hydroxy-3-oxo-2,5-diphenyl-2,3-dihydrothiophene 1,1-dioxide (1) reacts with primary amines according to their basicity to give the compounds 6a - h, and 7, resp.; with hydrazines the monohydrazones (8a - d) are obtained. Condensation with aliphatic diamines leads only in the case of 1,1-ethanediamine to a ring system (2), with the higher homologues to bridged compounds (3a - c). Reaction with methylenediamine dihydrochloride leads to the same product (5) as with ammonia. Active derivatives of carboxylic acids react with 1 to give mono- (9a,b) or bisacylation (10), in the case of thiophosgene the corresponding dioxole 11 is formed. With trialkyl phosphites 1 produces the vinylogue sulfonic esters 12a, b by simple alkylation, analogous to the reaction with diazomethane.
    Notes: 4-Hydroxy-3-oxo-2,5-diphenyl-2,3-dihydrothiophen-1,1-dioxid (1) reagiert mit primären Aminen je nach deren Basizität zu den Verbindungen 6a - h oder 7; mit Hydrazinen erfolgt Monohydrazonbildung zu 8a - d. Kondensation mit aliphatischen Diaminen führt nur im Falle des 1,2-Ethandiamins zum ringgeschlossenen Produkt (2), höhere homologe Diamine bilden verbrückte Verbindungen (3a - c). Die Reaktion mit Methandiamin-dihydrochlorid führt zu Produkt 5, das auch durch Umsetzung mit Ammoniak erhalten wird. Aktive Carbonsäurederivate setzen sich mit 1 zum Mono- (9a, b) bzw. Bisacylprodukt (10) um. Mit Thiophosgen liefert 1 das Dioxol 11; mit Trialkylphosphiten erfolgt Alkylierung zu den vinylogen Sulfonsäureestern 12a, b analog der Umsetzung mit Diazomethan.
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    URL: http://dx.doi.org/10.1002/cber.19801130232
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    Bis(pentamethylcyclopentadienyl)germanium und -zinn sowie (Pentamethylcyclopentadienyl)germanium- und -zinn-Kationen: Synthese, Struktur und Bindungsverhältnisse (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 757-769 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Bis(pentamethylcyclopentadienyl)germanium and -tin and (Pentamethylcyclopentadienyl)germanium- and -tin Cations: Synthesis, Structure, and Bonding PropertiesSynthesis and properties of bis(pentamethylcyclopentadienyl)germanium (2) and -tin (1) and of the ionic (pentamethylcyclopentadienyl)germanium- and -tin tetrafluoroborates 4 and 3 are described. The structures of 1 - 4 result from spectroscopic and analytical data and in the case of 1 and 3 also from X-ray structure analyses. The bonding in 1 - 4 is discussed on the basis of model MO calculations.
    Notes: Synthese und Eigenschaften des Bis(pentamethylcyclopentadienyl)germaniums (2) und -zinns (1) sowie der ionischen (Pentamethylcyclopentadienyl)germanium- und -zinn-tetrafluoroborate 4 und 3 werden beschrieben. Die Strukturen von 1 - 4 resultieren aus spektroskopischen und analytischen Daten sowie im Falle von 1 und 3 auch aus Röntgenstrukturanalysen. Elektronenstruktur und Bindungsverhältnisse in 1 - 4 werden auf der Basis von MO-Modellrechnungen diskutiert.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130233
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    Thermolyse von Oxazolin-5-onen, X. 3-Imidazoline und Δ3-Tetrahydropyrimidine durch Thermolyse von 3-Oxazolin-5-onen aus N-Acyldipeptiden (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 770-786 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thermolysis of Oxazolin-5-ones, X. 3-Imidazolines and Δ3-Tetrahydropyrimidines by Thermolysis of 3-Oxazolin-5-ones Derived from N-Acyl DipeptidesOn thermolysis 2-(acylaminomethyl)-3-oxazolin-5-ones (3a - g) undergo elimination of CO2 to give nitrile ylides which cyclize to 3-imidazolines 4a - g via intramolecular proton transfer. The 2-acylaminoethyl derivative 3h yields a Δ3-tetrahydropyrimidine 5h in an analogous manner. Compounds 3 may be easily obtained from N-acyl dipeptides 1. The temperature dependence of the 1H NMR spectra of 4 is discussed.
    Notes: Die Thermolyse von 2-(Acylaminomethyl)-3-oxazolin-5-onen (3a - g) führt unter Eliminierung von CO2 zu Nitril-yliden, welche nach innermolekularer Protonenübertragung zu 3-Imidazolinen 4a - g cyclisieren. Analog liefert das 2-(Acylaminoethyl)-Derivat 3h ein Δ3-Tetrahydropyrimidin 5h. Die Oxazolinone 3 sind aus N-Acyldipeptiden 1 leicht zugänglich. Die Temperaturabhängigkeit der 1H-NMR-Spektren von 4 wird diskutiert.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19801130234
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    Stereoselektive Synthesen von Alkoholen, IV. Konformationseinflüsse auf die Stereochemie der Allylsulfoxid-Sulfensäure-allylester-Umlagerung (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 856-863 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stereoselective Synthesis of Alcohols, IV. Conformational Factors Determining the Stereochemistry of the Allyl Sulfoxide/Allyl Sulfenate-RearrangementThe stereochemistry of the [2,3]sigmatropic rearrangement of the conformationally rigid allyl sulfoxides 5 revealed a 6.2 fold preference for axial formation of the new C — O-bond. This preference dominates the 3.1 fold preference for an exo-versus endo-transition state. These data form the basis for a discussion of the stereochemistry of rearrangement of the conformationally flexible allyl sulfoxides 1 and 13.
    Notes: Aus der Stereochemie der [2,3]sigmatropen Umlagerung der konformativ fixierten Allylsulfoxide 5 kann man eine 6.2-fache Präferenz für eine axiale Neuknüpfung der C — O-Bindung ableiten, die über eine 3.1-fache Präferenz für einen exo-Übergangszustand dominiert. Diese Vorstellungen wurden auf die Umlagerung der konformativ flexiblen Allylsulfoxide 1 und 13 übertragen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130307
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    Kumulierte Ylide, VII. Eine Methode zum Aufbau α,β-ungesättigter Carbonsäurederivate (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 912-918 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cumulated Ylides, VII. A Method for the Synthesis of α,β-Unsaturated Carboxylic CompoundsPhosphacumulene ylides 1 add alcohols, thiols, and NH-acidic compounds to form phosphoranes 3, which react with aldehydes to give esters, thiol esters, imidates, thioimidates, amidines, azolides, and sulfonamides of α,β-unsaturated carboxylic acids.
    Notes: Phosphacumulen-Ylide 1 addieren Alkohole, Thiole und NH-acide Verbindungen zu Phosphoranen 3, die sich mit Aldehyden zu Estern, Thiolestern, Imidsäureestern, Imidsäurethioestern, Amidinen, Azoliden sowie Sulfonamiden α,β-ungesättigter Carbonsäuren umsetzen lassen.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19801130311
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    Mikrobiologische Umwandlung von Steroiden, XVII. Darstellung von unterschiedlichen Mono- und Diketostrukturen von D-Homo-4-pregnen-3,20-dion und D-Homo-1,4-pregnadien-3,20-dion (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 203-220 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Microbial Transformations of Steroids, XVII. Preparation of Several Mono- and Diketo-structures of D-Homo-4-pregnene-3,20-dione and D-Homo-1,4-pregnadiene-3,20-dione11α- (2) and 15α-monohydroxy- (3), 6β,11α-(4), 11α,15α- (5), 12β,15α- (6), 15α,16α- (7), 7β,11α- (8), 11β,17α- (9), 7β,17α-dihydroxy- (11), and 17α-hydroxy-11-oxo-D-homoprogesterone (10) were prepared by microbiological transformations of D-homoprogesterone (1) with various fungi. The compounds were oxidized by the method of Jones before and after microbiological 1,2-dehydrogenation with Bacillus lentus to the corresponding keto-structures 12 to 17 and 20 respectively 26 to 30. The 14α-hydroxy-11-ketone 18 and 7α,14α-dihydroxy-11-ketone 19 were obtained by microbiological hydroxylation of the 11-ketone 12 with Curvularia lunata. Penicillium lilacinum degraded D-homoprogesterone (1) to D-homotestosterone.
    Notes: Durch mikrobiologische Umwandlung von D-Homoprogesteron (1) mit verschiedenen Pilzstämmen wurden 11α- (2) und 15α-Monohydroxy- (3), 6β,11α- (4), 11α,15α- (5), 12β,15α- (6), 15α,16α- (7), 7β,11α- (8), 11β,17α- (9), 7β,17α-Dihydroxy- (11) und 17α-Hydroxy-11-oxo-D-homo-progesteron (10) hergestellt. Die Verbindungen wurden vor und nach mikrobiologischer 1,2-Dehydrierung mit Bacillus lentus zu den entsprechenden Ketostrukturen 12 - 17 und 20 bzw. 26 - 30 nach Jones oxidiert. Ein 14α-Hydroxy-11-keton 18 und 7α,14α-Dihydroxy-11-keton 19 wurden durch mikrobiologische Zweithydroxylierung des 11-Ketons 12 mit Curvularia lunata erhalten. Penicillium lilacinum baute D-Homoprogesteron (1) zu D-Homotestosteron ab.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19801130121
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    Elektron-Donor-Acceptor-Verbindungen, XIX. Intramolekulare Chinhydrone der [3.3]Metacyclophan-Reihe: syn- und anti-6,9,15,18-Tetramethoxy[3.3]metacyclophane als Vorstufen (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 233-240 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Electron Donor-Acceptor Compounds, XIX. Intramolecular Quinhydrones of the [3.3]Metacyclophane Series: syn- and anti-6,9,15,18-Tetramethoxy[3.3]metacyclophanes as PrecursorsIn the context of the synthesis of [3.3]metacyclophane quinhydrones (e. g, 1 and 2) the stereoisomeric 7,10,17,20-tetramethoxy-2,13-dithia[4.4]metacyclophanes (5/6) were synthesized via 8 - 12. From the disulfones, prepared by oxidation of 5/6, by vacuum gas-phase pyrolysis (570°C/10-4 Torr) two stereoisomeric 6,9,15,18-tetramethoxy[3.3]metacyclophanes were obtained the assignment of which to the syn-constitution 3 and the anti-constitution 4 has been made on the basis of 1H NMR spectra. As experiments on thermal isomerisation show the conformational stability of 3/4 as well as 5/6 is remarkably high. - As side-products of the cyclisation of 11 and 12, and of the sulfone pyrolysis, resp., the compounds 13 - 16 were isolated.
    Notes: Mit dem Ziel der Synthese von Chinhydronen der [3.3]Metacyclophan-Reihe (z. B. 1 und 2) wurden die stereoisomeren 7,10,17,20-Tetramethoxy-2,13-dithia[4.4]metacyclophane (5/6) über die Vorstufen 8 - 12 synthetisiert. Aus den durch Oxidation von 5/6 erhaltenen Disulfonen entstanden durch Gasphasen-Vakuum-Pyrolyse (570°C/10-4 Torr) zwei stereoisomere 6,9,15,18-Tetramethoxy[3.3]metacyclophane, deren Zuordnung zur syn-Konstitution 3 und anti-Konstitution 4 aufgrund der 1H-NMR-Spektren getroffen wurde. Wie Versuche zur thermischen Isomerisierung zeigen, ist die konformative Stabilität von 3/4 wie auch von 5/6 bemerkenswert groß. - Als Nebenprodukte der Cyclisierung von 11 und 12 bzw. der Sulfon-Pyrolyse wurden die Verbindungen 13 - 16 isoliert.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130124
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    Elektron-Donor-Acceptor-Verbindungen, XX. Intramolekulare Chinhydrone der [3.3]Metacyclophan-Reihe: Synthese, Struktur, Stabilität und Charge-Transfer-Absorptionen von stereoisomeren [3.3]Metacyclophan-Chinhydronen (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 241-254 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Electron Donor-Acceptor Compounds, XX. Intramolecular Quinhydrones of the [3.3]Metacyclophane Series: Synthesis, Stability, and Charge Transfer Absorptions of Stereoisomeric [3.3]Metacyclophane QuinhydronesOn the attempt to synthesize the syn- and anti-[3.3]metacyclophane quinhydrones 1 and 2 by demethylation of 3 and 4, resp., and subsequent oxidation the same [3.3](2,6)-p-benzoquinonophane (5) was obtained which on catalytic hydrogenation yielded syn-[3.3]metacyclophane quinhydrone 1. Partial demethylation, however, and following oxidation led from 3 to the dimethyl ether 7 of the syn-quinhydrone 1, and analogously from 4 to the dimethyl ether 8 of anti-[3.3]-metacyclophane quinhydrone 2. The structural assignment of the stereoisomers was confirmed by an X-ray structure analysis of 7. In addition to 7 and 8, the corresponding monomethyl ethers 10 and 12 were obtained. - The anti-[3.3]metacyclophanes 8 and 12 undergo a complete thermal rearrangement to the syn-isomers 7 and 11, resp., from which a stronger ground state stabilisation by charge transfer interaction is concluded for the donor-acceptor systems of the syn-series. - The quinhydrones 7, 8, 10, 11, and 12 show broad, intensive charge transfer absorptions in the range from 300 to 550 nm which for the pairs of stereoisomers 7/8 and 11/12, in spite of the very different donor-acceptor orientation, are surprisingly similar: the absorption intensity of the CT band, however, is considerably stronger for the anti-quinhydrones than for their syn-isomers.
    Notes: Bei Versuchen zur Darstellung der syn- und anti-[3.3]Metacyclophan-Chinhydrone 1 und 2 wurde durch Demethylierung von 3 bzw. 4 und anschließende Oxidation dasselbe [3.3](2,6)-p-Benzochinonophan (5) erhalten, das durch katalytische Hydrierung syn-[3.3]Metacyclophan-Chinhydron 1 ergab. Partielle Demethylierung und anschließende Oxidation führten jedoch ausgehend von 3 zum Dimethylether 7 des syn-Chinhydrons 1 und entsprechend aus 4 zum Dimethylether 8 des anti-[3.3]Metacyclophan-Chinhydrons 2. Die Strukturzuordnung der Stereoisomeren wurde durch Röntgen-Strukturanalyse von 7 bestätigt. Neben 7 und 8 wurden die entsprechenden Monomethylether 10 und 12 erhalten. - Die anti-Verbindungen 8 und 12 lagern sich thermisch quantitativ in die syn-Isomeren 7 bzw. 11 um, woraus auf eine stärkere Grundzustands-Stabilisierung durch Charge-Transfer-Wechselwirkung bei den Donor-Acceptor-Systemen der syn-Reihe geschlossen wird. - Die Chinhydrone 7, 8, 10, 11 und 12 zeigen breite, intensive Charge-Transfer-Absorptionen im Bereich von 300 - 550 nm, die bei den Stereoisomeren-Paaren 7/8 und 11/12 trotz der sehr unterschiedlichen Donor-Acceptor-Orientierung überraschend ähnlich sind; die Absorptionsintensität der CT-Bande ist jedoch bei den anti-Chinhydronen beträchtlich größer als bei den syn-Isomeren.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130125
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    Fluorenylsilane, I. Darstellung und Strukturuntersuchung von Fluorenylsilanen mit funktionellen Gruppen am Silicium (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 278-288 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Fluorenylsilanes, I. Preparation and Structural Investigations of Fluorenylsilanes with Functional Groups at SiliconChloro-9-fluorenyldiphenylsilane (3a) and 9-fluorenyltris(trimethylsilyl)silane (3b) have been prepared by the reaction of the corresponding halosilanes with 9-fluorenyl lithium. The chloro substituent in 3a can be exchanged for other functional groups. With alkaline conditions cleavage of the fluorenyl-silicon bond may happen. The molecular structures of 3b and 9-fluorenyldiphenylsilanole (6a) have been determined by X-ray diffraction. In both compounds the substituents at the Cfluorenyl—Si bond are exactly staggered. The fluorenyl group in 3b is slightly folded, the Cfluorenyl—Si bond is lengthened to 194.7 (4) pm.
    Notes: Chlor-9-fluorenyldiphenylsilan (3a) und 9-Fluorenyltris(trimethylsilyl)silan (3b) wurden durch Umsetzung der entsprechenden Halogensilane mit 9-Fluorenyllithium dargestellt. Der Chlorsubstituent in 3a läßt sich gegen andere funktionelle Gruppen austauschen; im alkalischen Medium kann daneben die Fluoren-Silicium-Bindung gespalten werden. Von 3b und 9-Fluorenyldiphenylsilanol (6a) wurden Röntgenstrukturanalysen durchgeführt. In beiden Verbindungen stehen die Substituenten bezüglich der CFluorenyl— Si-Bindung streng gestaffelt. Der Fluorenyl-Rest in 3b ist leicht gefaltet, die CFluorenyl—Si-Bindung auf 194.7 (4) pm aufgeweitet.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130130
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    Die Oxidation von Hexathioethanen zu Tetrathioethen-Radikalkationen (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 289-301 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Oxidation of Hexathioethanes to Tetrathioethene Radical CationsThe oxidation of hexakis(alkylthio)ethanes (RS)3C — C(SR)3 by AlCl3/H2CCl2, NOBF4, or I2 yields tetrakis(alkylthio)ethene radical cations (RS)2Ċ=⊕C(SR)2. The dark violet tetrahydrotetrathiafulvalenium triiodide 1 · I3 (n = 2) has been obtained as a crystalline solid. Other derivatives such as the dibenzotetrathiafulvalene (2) and the quinodimethane (4) radical cations have been characterized by ESR spectroscopy in solution: The coupling constants and the g values reveal that the spin density accumulates preferentially at the S centers. The alkyl proton coupling is rationalized advantageously by angle-independent spin polarization. For tetrathiafulvalene, geometry-optimized MNDO calculations predict a lengthening of the central C = C bond on oxidation and the positive charge centered predominantly at sulfur.
    Notes: Die Oxidation von Hexakis(alkylthio)ethanen (RS)3C — C(SR)3 mit AlCl3/H2CCl2, NOBF4 oder I2 führt zu Tetrakis(alkylthio)ethen-Radikalionen (RS)2Ċ=⊕C(SR)2. Das schwarzviolette Tetrahydrotetrathiafulvalenium-triiodid 1 · I3 (n = 2) konnte in Substanz isoliert werden. Weitere Derivate wie das Dibenzotetrathiafulvalen- (2) und das Chinodimethan-(4)-Radikalion werden in Lösung ESR-spektroskopisch charakterisiert: Aus den Kopplungskonstanten und g-Faktoren folgt, daß sich die Spindichte überwiegend an den S-Zentren befindet. Die Alkylprotonen-Kopplungen lassen sich vorteilhaft mit winkelunabhängiger Spinpolarisation beschreiben. Für Tetrathiafulvalen ergeben geometrieoptimierte open-shell-MNDO-Berechnungen, daß sich die zentrale C = C-Bindung bei Oxidation verlängern, und daß die positive Ladung überwiegend am Schwefel zentriert sein sollte.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19801130131
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    Trimethylsilylcyanid als Umpolungsreagens, IV. Substituenteneffekte am acylierenden Nucleophil zur Steuerung der 1,2-/1,4-Addition an α,β-ungesättigte Ketone (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 324-332 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Trimethylsilyl Cyanide - A Reagent for Umpolung, IV. Substituent Effects in the Acylating Nucleophile for Directing 1,2-/1,4-Addition to α,β-Unsaturated KetonesMesityl oxide (6) is attacked by nucleophilic anions 5a - f in DME at the C-1 and/or C-3 position. Depending on the p-substituent in 5 the whole scale from 100% 1,2-adduct 7 (with 5a, X = N(CH3)2) to 100% 1,4-adduct 9 (with 5f, X = CN) is covered. In ether the amount of 9 is strongly enhanced. The control of regiospecificity has to be ascribed to differing “hardness” of 5a - f, since possible ion pairing produces opposite effects. The oxidation potentials of 5 and the reduction potential of 6 in DME exclude electron transfer before 1,4-addition. The easily reducible dienone 14, however, reacts with 5c via radicals.
    Notes: Die nucleophilen Anionen 5a - f greifen Mesityloxid (6) in DME in C-1- und/oder C-3-Position an, wobei in Abhängigkeit vom p-Substituenten in 5 die gesamte Skala von 100% 1,2-Addukt 7 (mit 5a, X = N(CH3)2) zu 100% 1,4-Addukt 9 (mit 5f, X = CN) durchlaufen wird. In Ether erhöht sich der Anteil an 9 erheblich. Die Steuerung muß der unterschiedlichen „Härte“ von 5a - f zugeschrieben werden, da eine mögliche Ionenpaarbildung gegenläufig wirkt. Die Oxidationspotentiale von 5 und das Reduktionspotential von 6 schließen in DME eine vorgelagerte Elektronenübertragung bei 1,4-Addition aus, während das leicht reduzierbare Dienon 14 mit 5c radikalisch reagiert.
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    URL: http://dx.doi.org/10.1002/cber.19801130133
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    Kernresonanzspektroskopische Untersuchungen an Bor-Verbindungen, XVII. 17O-NMR-Studien an Organyloxyboranen, Organyloxydiboranen(4), Dioxaborolanen und Boroxinen (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 333-341 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: NMR Studies of Boron Compounds, XVII. 17O NMR Studies on Organyloxyboranes, Organyloxydiboranes(4), Dioxaborolanes, and Boroxins17O chemical shifts of 30 boron-oxygen compounds containing tricoordinate boron atoms can be interpreted in terms of B - O(pp)π interaction. In consonance with other physical data a decrease in the π bond order is indicated by the δ17O data along the series (R2B)2O 〉 (RBO)3 〉 R2BOR 〉 RB(OR)2 〉 B(OR)3 (R either CH3 or C2H5). Natural abundance 17O NMR spectra are recorded by PFT NMR spectroscopy in relatively short time as “routine” measurements.
    Notes: Die 17O-chemischen Verschiebungen von 30 Bor-Sauerstoff-Verbindungen, die dreifach koordiniertes Bor enthalten, sind mit B - O(pp)π-Wechselwirkung zu interpretieren. In Übereinstimmung mit anderen physikalischen Daten legen die δ17O-Werte eine Abnahme der π-Bindungsordnung in der Reihe (R2B)2O 〉 (RBO)3 〉 R2BOR 〉 RB(OR)2 〉 B(OR)3 (R = CH3 oder C2H5) nahe. 17O-NMR-Spektren von Verbindungen mit natürlicher Isotopenhäufigkeit werden mittels PFT-NMR-Spektroskopie relativ rasch in „Routinemessungen“ erhalten.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19801130134
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    Synthese von Spirocyclohexadienonen und deren unerwartete Umlagerung zu tricyclischen Verbindungen (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 669-675 
    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 Spirocyclohexadienones and their Rearrangement to Tricyclic Compounds(4-Hydroxyphenyl)acetic acid reacts with diisopropyl- and dicyclohexylcarbodiimide to yield the spirocyclohexadienones 1 and 2. When treated with BF3-etherate, these compounds rearrange to give 3 and 4. The structure of 3, concluded from the NMR-spectra, was confirmed by rearranging the corresponding deuterium-labeled dienone 1a and determining the position of deuterium in the rearranged compound 3a.
    Notes: (4-Hydroxyphenyl)essigsäure reagiert mit Diisopropyl- und Dicyclohexylcarbodiimid zu den Spirocyclohexadienonen 1 und 2. Diese Verbindungen lagern sich mit BF3-Etherat zu den Verbindungen 3 und 4 um. Die aufgrund der Kernresonanzspektren postulierte Konstitution der Verbindung 3 wurde bestätigt, indem das entsprechende deuteriummarkierte Dienon 1a umgelagert und die Position des Deuteriums im Umlagerungsprodukt 3a aus den Kernresonanzspektren bestimmt wurde.
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    URL: http://dx.doi.org/10.1002/cber.19801130224
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    Cholestano-cobaloxime und Cholestano-rhodoxime. Synthese, Charakterisierung und Umlagerung von Modellverbindungen für die Aktivstelle von Methylmalonyl-CoA-Mutase (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 650-668 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparative, Spectroscopic, and Crystallographic Investigations on Phosphinato Complexes of Rhenium with Bidentate Nitrogen LigandsCholestano-cobaloximes and cholestano-rhodoximes, three diastereoisomers of each constitution, were synthesised from cholestane-2,3-dione dioxime (3). The diastereoisomeric complexes were separated and characterised by their spectra. One of the axial ligands was invariably pyridine, the other either chlor (9), methyl (10), 2,2-bis(methoxycarbonyl)propyl (11), 2,2-bis(benzyl-oxycarbonyl)propyl (12), or 2,2-bis(2-naphthylmethoxycarbonyl)propyl (13 and 14). Irradiation of the complexes 11, 12, 13, and 14 in ethanol or 2-propanol afforded, apart from dimethylmalonic diester, other products among which was the corresponding methylsuccinic diester in yields of approx. 1, 20, 23, and 13%, respectively. The methylsuccinic acid bis(2-naphthylmethyl ester) obtained from the irradiation of the diastereoisomeric cholestano-cobaloximes 13a, b and c was found to be practically racemic.
    Notes: Aus Cholestan-2,3-dion-dioxim (3) wurden jeweils drei diastereomere Cholestano-cobaloxime und Cholestano-rhodoxime synthetisiert, die getrennt und spektroskopisch charakterisiert wurden. Pyridin diente durchweg als einer der axialen Liganden, der andere war Chlor (9), Methyl (10), 2,2-Bis(methoxycarbonyl)propyl (11), 2,2-Bis(benzyloxycarbonyl)propyl (12) oder 2,2-Bis(2-naphthylmethoxycarbonyl)propyl (13 und 14). Bestrahlung der Komplexe 11, 12, 13 und 14 in Ethanol oder 2-Propanol gab neben den Dimethylmalonsäureestern und weiteren Produkten auch die entsprechenden Methylbernsteinsäure-diester in Ausbeuten von etwa 1, 20, 23 und 13%. Der aus den diastereomeren Cholestano-cobaloximen 13a, b und c erhaltene Methylbernsteinsäure-bis(2-naphthylmethylester) war praktisch racemisch.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130223
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    Gespannte Anthrachinonophane und Anthracenophane (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 676-689 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Strained Anthraquinonophanes and AnthracenophanesThe clamped anthraquinonophane 3 and anthracenophanes 4, 5 have been synthesized. Their spectroscopic properties are compared with those of the open chained compounds 8 and 10 and the corresponding phanes (12a - 15a and 16 - 18) with longer bridges. The clamping causes significant hypsochromic shifts in the UV spectra and distinct shifts in the 1H-/13C-NMR-spectra. Reaction of the anthraquinonophane 3 with an excess of methyllithium selectively yields the exocyclic methyl-substituted anthracenophane 5.
    Notes: Die verklammerten Anthrachinonophane 3 und Anthracenophane 4, 5 wurden erstmals synthetisiert und ihre spektroskopischen Eigenschaften mit denen offenkettiger (8 und 10) und mit längeren Brücken überspannter (12a - 15a und 16 - 18) Anthrachinone und Anthracene verglichen. Die Verklammerung bedingt signifikante hypsochrome Verschiebungen im UV-Spektrum sowie deutliche Verschiebungen einzelner Signale in den 1H-/13C-NMR-Spektren. Umsetzung des Anthrachinonophans 3 mit überschüssigem Methyllithium führt selektiv zu der exocyclisch methylsubstituierten Anthracenverbindung 5.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130225
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  • 72
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    Asymmetrische Synthesen, VI. Synthese optisch aktiver Aziridine (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 722-727 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Asymmetric Syntheses, VI. Synthesis of Optically Active AziridinesThe optically active tetrahydro-1,4-oxazine derivatives 1a - e are converted via their respective tosylates 2a - e to the optically active aziridine derivatives 3a - e. The constitution and configuration of 3a - e are ascertained spectroscopically. The nitrogen inversion is investigated by low and high temperature 1H-NMR spectroscopy.
    Notes: Die optisch aktiven Tetrahydro-1,4-oxazin-Derivate 1a - e werden über die entsprechenden Tosylate 2a - e in die optisch aktiven Aziridin-Derivate 3a - e übergeführt. Die Konstitution und Konfiguration von 3a - e werden spektroskopisch ermittelt. Durch 1H-NMR-spektroskopische Tief-und Hochtemperaturmessungen wird die Inversion am Stickstoff untersucht.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130229
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  • 73
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    Sterisch gehinderte Olefine, V. Synthese und Röntgenstrukturanalyse von trans-1-Ethyl-2-(1-ethyl-2-adamantyliden)adamantan, einem hochgespannten Ethylen. Vergleich mit Kraftfeld-Rechnungen (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 739-749 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Sterically Hindered Olefins, V. Synthesis and X-Ray Structure Analysis of trans-1-Ethyl-2-(1-ethyl-2-adamantylidene)-adamantane, a Highly Hindered Ethylene. Comparison with Force-Field CalculationsSynthesis of trans-1-ethyl-2-(1-ethyl-2-adamantylidene)adamantane (2) starting from 1-ethyl-2-adamantanone (1) is described. The structure of 2 was determined by X-ray structure analysis (2(C2) symmetry). Steric hindrance results in a torsion and an out-of-plane deformation of the CC double bond, and also is evident by characteristic elongations of bond lengths and by bond angle deformations. The CC double bond, e.g., is elongated to 1.358 Å, the vinylic bonds with a quaternary carbon atom are elongated to 1.563 Å. The strongest bond angle deformation occurs at the substituted sp3-hybridized C-atoms in the allylic positions increasing one angle to 122.1°. The geometry of 2 is compared with the parent compound adamantylideneadamantane (3). Calculations using Allinger's force-field show for 2 and 3 a sufficient agreement with the experimentally determined structure parameters and an increased strain energy by 28.1 kcal mol--1. The force-field calculations have been extended to the analogous adamantylideneadamantanes 4 - 7.
    Notes: Es wird die Synthese von trans-1-Ethyl-2-(1-ethyl-2-adamantyliden)adamantan (2) aus 1-Ethyl-2-adamantanon (1) beschrieben. Die Struktur von 2 wurde durch Röntgenstrukturanalyse bestimmt (2(C2)-Symmetrie). Die starke sterische Spannung in 2 äußert sich in einer Torsion um die C = C-Doppelbindung bei einer gleichzeitigen pyramidalen Verzerrung der Konfiguration ihrer C-Atome, sowie in charakteristischen Bindungsaufweitungen und Winkeldeformationen. Die C = C-Doppelbindung verlängert z.B. auf 1.358 Å; die vinylständigen C — C-Einfachbindungen mit einem quartären Kohlenstoff verlängern auf 1.563 Å. Die stärkste Winkeldeformation erfolgt an den substituierten, allylständigen sp3-hybridisierten C-Atomen (Vergrößerung eines Winkels auf 122.1°). Die Geometrie von 2 wird mit dem weniger gespannten, unsubstituierten Adamantylidenadamantan (3) verglichen. Kraftfeld-Rechnungen nach Allinger für 2 und 3 ergeben eine hinreichend gute Übereinstimmung mit den experimentell ermittelten Strukturparametern und eine um 28.1 kcal/mol höhere Spannungsenergie für 2. Die Kraftfeld-Rechnungen wurden auf analoge Adamantylidenadamantan-Derivate (4 - 7) ausgedehnt.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130231
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  • 74
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    Beiträge zur Chemie des Bors, CVI. Quecksilber-(dimethylboryl)methylamide (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 791-794 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Contributions to the Chemistry of Boron, CVI. Mercury (Dimethylboryl)methylamidesThe volatile compounds Hg[NCH3 — B(CH3)2]2 and CH3Hg — NCH3 - B(CH3)2 have been prepared. They are stable up to 80°C and show no assoziation in solution or the gaseous phase either through Hg — N or B — N coordinative bonding.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130236
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  • 75
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    Reaktionen von Oxazolin-5-on-Anionen, IX. Ein einfaches Verfahren zur Darstellung von Derivaten der δ-Aminolävulinsäure und verwandter Verbindungen (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 787-790 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reactions of Oxazolin-5-one Anions, IX. A Simple Procedure for the Preparation of δ-Aminolevulinic Acid Derivatives and Related CompoundsCyclization of Z-dipeptides 1 with acetic anhydride leads to 2-oxazolin-5-ones, which yield the corresponding 3-oxazolin-5-ones 2 by base-catalyzed addition of ethyl acrylate or acrylonitrile. Hydrolysis of 2a gives ethyl δ-(benzyloxycarbonylamino)levulinate (3a), which may be converted into several N-protected derivatives 3e - i. Via the same procedure the homologue 3b and the nitriles 3c, d are easily obtained.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130235
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  • 76
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    Zur Konformation von 2-Alkyl-3-amino- und 2-Alkyl-3-ethoxyacroleinen (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 795-799 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Note on the Conformation of 2-Alkyl-3-amino- and 2-Alkyl-3-ethoxyacroleins2-Alkyl-3-aminoacroleins are found by 1H- and 13C-NMR to prefer the E-configuration at 30°C in hydrogen bonding solvents. In less protic solvents, the Z-s-Z isomer is recognized which predominates at lower temperatures. The corresponding 3-ethoxyacroleins only exist in the E-configuration under these conditions as their Z-s-Z conformation cannot be stabilized by intramolecular hydrogen bonding.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130237
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  • 77
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    Stereoselektive Synthesen von Alkoholen, III. Stereochemie der [2,3]sigmatropen Umlagerung von (1-Cycloalkenylmethyl)-sulfoxiden (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 845-855 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stereoselective Synthesis of Alcohols, III. Stereochemistry of the [2,3]Sigmatropic Rearrangement of (1-Cycloalkenylmethyl) SulfoxidesRearrangement of the chiral allyl sulfoxides 17 and 20 proceeded via the exo-transition state 14 to give the α-methylenecycloalkanols 18 and 21 in high enantiomeric purity. The extent of chirality transferred was less (44 and 60%) on rearrangement of the allyl sulfoxides 9 and 16.
    Notes: Bei der Umlagerung der chiralen Allylsulfoxide 17 und 20 über den exo-Übergangszustand 14 konnten die α-Methylencycloalkanole 18 und 21 in hoher Enantiomerenreinheit erhalten werden. Bei den Allylsulfoxiden 9 und 16 war das Ausmaß der Chiralitätsübertragung mit 44% und 60% geringer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130306
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  • 78
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    Synthese makrotricyclischer Amine (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 864-874 
    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 Macrotricyclic AminesThe synthesis of the macrotricyclic amines 14a and b with a tetrahedron skeleton is achieved by three successive cyclisations using high dilution conditions (overall yields 5.6 and 2.5%, resp.).
    Notes: Die Synthese der makrotricyclischen Tetraamine 14a und b mit Tetraederstruktur wird durch drei Cyclisierungsschritte nach dem Verdünnungsprinzip in Gesamtausbeuten von 5.6 bzw. 2.5% erreicht.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130308
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  • 79
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    Die Reaktion von Stickstoff mit Dehydrobenzol in der Koordinationssphäre von Titan (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 70-78 
    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 Dinitrogen with Benzyne in the Coordination Sphere of TitaniumThe formation of aniline from dinitrogen during the thermolysis of diphenyltitanocene (1) and in the system (C5H5)2TiCl2 (3) + Mg + o-bromofluorobenzene (4) + N2 has been found to proceed via N2 reaction with intermediate Ti-benzyne complex (2). This is indicated by the isomeric composition of toluidines obtained from N2 and ditolyltitanocenes, the formation of [2-D1]aniline in the system 3 + Mg + 4 + N2 on hydrolysis with D2O and by nitrogen isotope fractionations at natural 15N-abundance in the reaction products.
    Notes: Die Bildung von Anilin aus Stickstoff bei der Thermolyse von Diphenyltitanocen (1) und im Reaktionssystem (C5H5)2TiCl2 (3) + Mg + o-Bromfluorbenzol (4) + N2 verläuft über die Reaktion von N2 mit einem intermediären Titan-Dehydrobenzol-Komplex (2). Das ergibt sich aus der Isomerenverteilung von Toluidinen, die aus N2 und Ditolyltitanocenen erhalten wurden, aus der Bildung von [2-D1]Anilin bei Hydrolyse des Systems 3 + Mg + 4 + N2 mit D2O sowie aus Stickstoffisotopen-Fraktionierungen in den Reaktionsprodukten mit natürlicher 15N-Häufigkeit.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130110
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  • 80
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    Über Acylcarbodiimide, III. Darstellung und Reaktionen von (Thiocarbamoyl)carbodiimiden (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 79-89 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Acylcarbodiimides, III. Preparation and Reactions of (Thiocarbamoyl)carbodiimidesStarting from 1,1,5-trisubstituted dithiobiuretes (1) and with the aid of cyanuric trichloride/triethylamine several (thiocarbamoyl)carbodiimides (2) were prepared and partly isolated. This procedure can be used only in special cases for the preparation of 1,1-dialkyl-5-aryl-dithiobiuretes. Carbodiimides without a bulky substituent (R′) are prone to dimerization. Several dimers 4 were isolated, the structure of them was elucidated. Addition of water, alcohols, and amines afforded the thiocarbamoylureas 5, isoureas 7 and guanidines 6, cycloaddition of different acyl isothiocyanates and of benzoyl isocyanate gave the 1,3,5-thiadiazines 8 and 9.
    Notes: Aus 1,1,5-trisubstituierten Dithiobiureten (1) wurden mit Cyanurchlorid/Triethylamin eine Reihe von (Thiocarbamoyl)carbodiimiden (2) hergestellt und z. T. isoliert. Das Verfahren ist auf 1,1-Dialkyl-5-aryl-dithiobiurete nur begrenzt anwendungsfähig. Carbodiimide 2 ohne sperrigen Rest R′ neigen zur Dimerisierung; mehrere Dimere 4 wurden isoliert und in der Konstitution geklärt. Addition von Wasser, Alkoholen und Aminen lieferte die entsprechenden (Thiocarbamoyl)harnstoffe (5), -isoharnstoffe (7) und -guanidine (6). Cycloaddition von verschiedenartigen Acylisothiocyanaten und von Benzoylisocyanat führten zu den 1,3,5-Thiadiazinen 8 und 9.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130111
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    Reaktionen von (Dichlorphosphinyl)methansulfonylchlorid (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 142-151 
    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 (Dichlorophosphinyl)methanesulfonyl ChlorideSubstitution of chlorine by fluorine in (dichlorophosphinyl)methanesulfonyl chloride (2) Cl2P(O)CH2SO2Cl leads to the fluorides F2P(O)CH2SO2X (X = Cl, F); their reactions leading to the fluorophosphorane F4PCH2SO2F and fluorophosphate anions of the type [F5PCH2SO2X]- and [O(F)P(O)CH2SO2X]- (X = Cl, F) were investigated. Hydrolysis of 2 yields the acid (HO)2P(O)CH2SO2OH, from which esters and amides have been derived. The conversion of the esters to α,β-unsaturated sulfonic acid derivatives via the Horner-Wittig reaction is also described.
    Notes: Substitution von Chlor durch Fluor in (Dichlorphosphinyl)methansulfonylchlorid (2), Cl2P(O)CH2SO2Cl liefert die Fluoride F2P(O)CH2SO2X (X = Cl, F), deren Umwandlung zum Fluorphosphoran F4PCH2SO2F und zu Fluorophosphat-Anionen des Typs [F5PCH2SO2X]- bzw. [O(F)P(O)CH2SO2X]- (X = Cl, F) untersucht wird. Die Hydrolyse von 2 führt zur Säure (HO)2P(O)CH2SO2OH, von der Ester und Amide dargestellt werden. Die Ester werden in einer Horner-Wittig-Reaktion in α,β-ungesättigte Sulfonsäureverbindungen umgewandelt.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130115
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  • 82
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    Herstellung von methoxythiocarbonyl-substituierten Harnstoffen (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 165-170 
    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 Methoxythiocarbonyl Substituted UreasThe alkali metal salts 4 of phenylthiocarbamic O-methyl ester (1) yields with phosgene a carbonyl chloride (5), which is a suitable starting material for the preparation of the hitherto unknown group of methoxythiocarbonyl substituted ureas. In its reactions with carbonyl chlorides or sulfonyl chlorides, 4 shows the typical behaviour of an ambident anion.
    Notes: Die Alkalisalze 4 des Phenylthiocarbamidsäure-O-methylesters (1) liefern mit Phosgen ein Säurechlorid (5), welches einen bequemen Zugang zur bisher unbekannten Gruppe der methoxythio-carbonyl-substituierten Harnstoffe 6 eröffnet. Die Umsetzung von 4 mit Carbonylchloriden bzw. mit Sulfonylchloriden zeigt, daß 4 das typische Verhalten einer ambifunktionellen Verbindung aufweist.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130117
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    Umsetzung von substituierten Hydrazonen mit Thionylchlorid und Sulfurylchlorid (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 183-192 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reaction of Substituted Hydrazones with Thionyl Chloride and Sulfuryl ChlorideTreatment of acetylhydrazones 2, ethoxycarbonylhydrazones 3, p-tolylsulfonylhydrazones 4 or semicarbazones 5 with thionyl chloride leads to the 1,2,3-thiadiazoles 6a-o. Sulfuryl chloride on the other hand accomplishes the transfer of chlorine without incorporating a sulfur atom. The new synthesized 1,2,3-thiadiazoles 6g-o are characterized in detail by spectroscopic methods.
    Notes: Die Einwirkung von Thionylchlorid auf Acetylhydrazone 2, Ethoxycarbonylhydrazone 3, p-Tolylsulfonylhydrazone 4 oder Semicarbazone 5 führt zu den 1,2,3-Thiadiazolen 6a-o. Sulfurylchlorid dient dagegen lediglich als Chlorüberträger; Schwefel wird nicht eingebaut. Für die neu auf diesen Wegen synthetisierten 1,2,3-Thiadiazole 6g-o wird eine eingehende spektroskopische Charakterisierung durchgeführt.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130119
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    Eine verbesserte Methode zur Darstellung von 1,3,3-Triethyl-2-methylenindolin (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 391-394 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An Improved Method for the Synthesis of 1,3,3-Triethyl-2-methyleneindoline1,3,3-Triethyl-2-methyleneindoline (8) has been synthesized in 40% yield by alkylation of 2-methylindole with iodoethane in ethanol at 100 - 110°C/50 bar using an improved separation procedure. The 1H- and 13C-NMR spectra of 8 and its tetrafluoroborate salt are examined.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130138
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    Beiträge zur Chemie des Bors, CIV. Neue Ringsysteme mit Dibor-Einheiten als Ringglieder: Dithiadisilaboracyclopentane, Dithiatriborolane und Dithiatetraborinane (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 342-357 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Chemistry of Boron, CIV. New Ring Systems Containing Diboron Units: Dithiadisilaboracyclopentanes, Dithiatriborolanes, and DithiatetraborinanesThe pyridine-catalysed comproportionation between the cyclothiasilanes 1 or 4 and the dithiatetrasilacyclohexane 2 yields the dithiatrisilacyclopentane 3. 3 reacts with R2N(Cl)B - B(Cl)NR2 (5), and the R2Si - SiR2 group is specifically eliminated from 3 yielding the dithiasiladiboracyclopentane 6, which is also obtained from 5 and 1 or 4, respectively. Further action of 5 on 6 results in the dimethylamino derivative of a dithiatetraborinane (7). Moreover, a dithiadisilaboracyclopentane (8) results from the S2Si4 system 2 and phenylborane dichloride, and finally, a dithiatriborolane (10) is obtained from 6 and CH3B(SCH3)2. The new heterocyclic compounds were fully characterized chemically and spectroscopically. The X-ray structure analysis of 6 and 7 reveals nonplanar rings with short B — N bonds.
    Notes: Die mit Pyridin katalysierte Komproportionierung der Cyclothiasilane 1 und 4 mit dem Dithiatetrasilacyclohexan 2 liefert das Dithiatrisilacyclopentan 3. Dieses reagiert spezifisch mit R2N(Cl)B - B(Cl)NR2 (5) zu einem Dithiasiladiboracyclopentan (6), ebenfalls erhältlich aus 5 und 1 bzw. 4. Mit weiterem 5 setzt sich 6 zum Dimethylamino-Derivat eines Dithiatetraborinans (7) um. Ein Dithiadisilaboracyclopentan (8) entsteht aus dem S2Si4-System 2 und Phenylbordichlorid, ein Dithiatriborolan-Derivat (10) aus 6 und CH3B(SCH3)2. Die neuen Heterocyclen werden chemisch und spektroskopisch charakterisiert. Die Röntgenstrukturanalyse sicherte für 6 und 7 nichtplanare Ringsysteme mit kurzen B — N-Bindungen.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130135
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  • 86
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    Einfache Synthese neuer 1,3,9-Triazaanthracene (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 395-397 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Simple Synthesis of Novel 1,3,9-TriazaanthracenesWittig reaction of the bromoacetate 1 with aryl isocyanates gives rise to the 10-hydroxy- 9 and 10-amino-2,4-dioxo-1,3,9-triazaanthracenes 10. These have not yet been described.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130139
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  • 87
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    Masthead (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980) 
    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.19801130201
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  • 88
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    1,4-Addition von Grignard-Verbindungen an α,β-ungesättigte Cyanessigsäure-ethylester (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 401-407 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 1,4-Addition of Grignard Compounds to α,β-Unsaturated Ethyl Cyanoacetates1,4-Addition of several Grignard compounds and hydrogen cyanide to the α,β-unsaturated ethyl cyanoacetates 1 and 4 leading to 2a - n and 5a - d.
    Notes: Die 1,4-Addition von verschiedenen Grignard-Verbindungen und Blausäure an die α,β-ungesättigten Cyanessigsäure-ethylester 1 und 4 unter Bildung von 2a - n und 5a - d wurde untersucht.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130202
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  • 89
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    Kolbe-Synthese von 3,11-Dimethyl-2-nonacosanon, ein Sexuallockstoff der Deutschen Hausschabe Blattella germanica (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 451-456 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Kolbe Synthesis of 3,11-Dimethyl-2-nonacosanone, a Pheromone of the German Cockroach Blattella germanica3,11-Dimethyl-2-nonacosanone (5) is synthesized by coelectrolysis of 6-methyltetracosanoic acid (3b) with 5-methyl-6-oxoheptanoic acid (4). 3b is obtained by hydrolysis of the corresponding methyl ester 3a, which is prepared from 3-methylheneicosanoic acid (2) by coelectrolysis with methyl glutarate. The sec-butyl ester of 2 is obtained by 1,4-addition of octadecylmagnesium bromide to sec-butyl crotonate (1). 4 can be prepared by alkylation of potassium ethyl 2-methyl-acetoacetate with ethyl 4-bromobutyrate via 6.
    Notes: 3,11-Dimethyl-2-nonacosanon (5) wird durch Coelektrolyse von 6-Methyltetracosansäure (3b) mit 5-Methyl-6-oxoheptansäure (4) synthetisiert. 3b wird durch Verseifung des entsprechenden Methylesters 3a gewonnen, der aus 3-Methylheneicosansäure (2) durch Coelektrolyse mit Glutarsäure-monomethylester erhältlich ist. Den sek-Butylester von 2 liefert die 1,4-Addition von Octadecylmagnesiumbromid an Crotonsäure-sek-butylester (1). 4 läßt sich durch Alkylierung von Kalium-2-methylacetessigsäure-ethylester mit 4-Brombuttersäure-ethylester über 6 darstellen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130205
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  • 90
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    Ein Beitrag zum Mechanismus der licht-induzierten Isomerisierungen des 4-Methylenbicyclo[3.1.0]hex-2-en-Systems (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 511-519 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A Contribution to the Mechanism of Light-induced Isomerizations of the 4-Methylenebicyclo[3.1.0]hex-2-eneDeuterium-labelling of 1,2,3,5,6-exo-pentamethyl-4-methylenebicyclo[3.1.0]hex-2-ene (exo-1) and 1,2,3,5,6-endo-pentamethyl-4-methylenebicyclo[3.1.0]hex-2-ene (endo-1) was used to get insight into the mechanisms of the reversible photo-isomerization exo-1 ⇌ endo-1 and of their light-induced rearrangements to 1,2,3,4,6-pentamethyl-5-methylene-1,3-cyclohexadiene (2).
    Notes: Durch Verfolgung des Verbleibs von Deuterium im markierten 1,2,3,5,6-exo-Pentamethyl-4-methylenbicyclo[3.1.0]hex-2-en (exo-1) und 1,2,3,5,6-endo-Pentamethyl-4-methylenbicyclo[3.1.0]-hex-2-en (endo-1) wurden Hinweise über die Mechanismen der reversiblen Photo-Isomerisierung exo-1 ⇌ endo-1 und der gleichfalls licht-induzierten Umlagerung dieser Verbindungen zum 1,2,3,4,6-Pentamethyl-5-methylen-1,3-cyclohexadien (2) erhalten.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130209
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  • 91
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    Bernd Eistert. 1902-1978 (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. XXIX 
    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.19801130302
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  • 92
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    Trichlorvinylketenimine aus Perchlorbutenin und Cycloaddition von Trichloracetylisocyanat zu 4H-1,3-Oxazin-4-onen (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 811-818 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Trichlorovinylketene Imines from Perchlorobutenyne and Cycloaddition of Trichloroacetyl Isocyanate to 4H-1,3-Oxazin-4-onesThe reaction of perchlorobutenyne (1) with primary aliphatic amines leads to the ketene imines 3. The stability of 3 increases with spatial requirement of amino groups. Therefore only 3e - g may be isolated in pure form. Hydrolysis of 3 yields the carboxamides 4. 4e is furthermore hydrolyzed to the known acid 5. - The cycloaddition reaction of 3 with trichloroacetyl isocyanate is followed by tautomerization to the 4H-1,3-oxazin-4-ones 8 in good yield. When trated with aqueous ethanol or absolute methanol ring opening of 8 occurs with formation of substituted malonamides 7 and 10, respectively. The structure of 8 is confirmed by further degradation of 7 to 4.
    Notes: Die Umsetzung von Perchlorbutenin (1) mit primären aliphatischen Aminen liefert die Ketenimine 3, deren Stabilität mit dem Raumbedarf der Aminogruppen zunimmt. In reiner Form sind daher nur 3e-g isolierbar. Die Hydrolyse von 3 ergibt die Säureamide 4. 4e wird weiter zu der bekannten Säure 5 hydrolysiert. - Durch Cycloaddition von Trichloracetylisocyanat an 3 und nachfolgende Tautomerisierung entstehen die 4H-1,3-Oxazin-4-one 8 in guter Ausbeute. Diese erfahren mit wäßrigem Ethanol oder absolutem Methanol eine Ringöffnung zu den substituierten Malonamiden 7 bzw. 10. Der weitere Abbau von 7 zu 4 ist konstitutionsbeweisend für die Oxazinone 8.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130303
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  • 93
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    Stereoselektive Synthesen von Alkoholen, I. C — C-Verknüpfende Synthese von Allylalkoholen aus Aldehyden und Ketonen (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 819-830 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stereoselective Synthesis of Alcohols, I. Synthesis of One-Carbon Homologous Allyl Alcohols from Aldehydes or KetonesThe high yield conversion of aldehydes and ketones 2 to the one-carbon homologous allyl alcohols 3 is achieved by condensation to the vinyl sulfoxides 7, isomerisation to the allyl sulfoxides 9, and subsequent [2,3]sigmatropic rearrangement.
    Notes: Die Umwandlung von Aldehyden und Ketonen 2 in die um ein C-Atom reicheren Allylalkohole 3 gelingt durch Umsetzung zu den Vinylsulfoxiden 7, deren Isomerisierung zu den Allylsulfoxiden 9 und nachfolgende [2,3]sigmatrope Umlagerung.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130304
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  • 94
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    Stereoselektive Synthesen von Alkoholen, II. Stereochemie der [2,3]sigmatropen Umlagerung 3-substituierter 2-Alkenylsulfoxide (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 831-844 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stereoselective Synthesis of Alcohols, II. Stereochemistry of the [2,3]Sigmatropic Rearrangement of 3-Substituted 2-Alkenyl SulfoxidesRearrangement of the 3-E-substituted allyl sulfoxides 5 to the allyl alcohols 19 and 30 proceeds with low enantiomeric selectivity. In contrast, the 3-Z-substituted allyl sulfoxide 7b rearranged uniformly via the endo-transition state 26.
    Notes: Bei der Umlagerung von 3-E-substituierten Allylsulfoxiden 5 weisen die so erhaltenen Allylalkohole 19 und 30 nur geringe Enantiomerenreinheit auf. Das 3-Z-substituierte Allylsulfoxid 7b lagert dagegen einheitlich über den endo-Übergangszustand 26 um.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130305
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  • 95
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    Synthese und Struktur kristallisierter natriumorganischer Verbindungen aus Phosphor-Yliden (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 902-911 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Structure of Crystalline Sodiumorganic Compounds from Phosphorus YlidesThe two ylides (C6H5)2P - CH = P(C6H5)2 - CH2C6H5 (4) and C6H5CH2(C6H5)2P = CH - P(C6H5)2 = CHC6H5 (5) are synthesized from (C6H5)2P - CH2 - P(C6H5)2 (1) via their corresponding benzylphosphonium salts 2 und 3. The double ylide 5 exists solely in the above conjugated form, in contrast to most other R3PCPR3 molecules, where the cumulated isomer is preferred. There is rapid proton scrambling between benzyl and benzylidene hydrogens as detected by NMR spectroscopy. 4 and 5 react with NaNH2 to form coloured sodium complexes, in which the metal is bonded via the benzylide functions. NMR spectra indicate a symmetrical coordination site for Na+ above the benzylidene ring. The coordination sphere is completed by ether and/or tetrahydrofurane molecules. In an X-ray structure analysis of 6, which crystallizes with one (C2H5)2O and one C4H8O molecule, the details of the structure were elucidated. A 23Na NMR spectrum confirms the extremely asymmetrical array of ligands at the metal center. In the e.i. mass spectrum the sodium-containing molecular ion is observed.
    Notes: Aus (C6H5)2P — CH2 — P(C6H5)2 (1) werden über die zugehörigen Benzylphosphoniumsalze 2 und 3 die beiden Ylide (C6H5)2P — CH = P(C6H5)2 — CH2C6H5 (4) und C6H5CH2(C6H5)2P = CH — P(C6H5)2 = CHC6H5 (5) synthetisiert. Letzteres existiert im Gegensatz zu anderen R3PCPR3-Molekülen ausschließlich als konjugiertes Doppel-Ylid und zeigt raschen Protonenaustausch zwischen Benzyl-und Benzylidengruppe. 4 und 5 reagieren mit NaNH2 zu tieffarbigen Natriumkomplexen, in denen das Metall über die Benzylidfunktionen gebunden ist. NMR-Spektren zeigen eine symmetrische Bindung des Metalls an den Benzylidenring an. Die Koordinationssphäre des Na+ wird durch Ether- und/oder Tetrahydrofuranmoleküle ergänzt. Eine Röntgenstrukturanalyse von 6, das aus Ether mit je 1 Molekül Ether und Tetrahydrofuran kristallisiert, klärte Details der Bindungsverhältnisse in diesen neuen natriumorganischen Verbindungen. Das 23Na-NMR-Spektrum bestätigt die außerordentlich unsymmetrische Umgebung des Metalls. Im Massenspektrum wird das natriumhaltige Molekül-Ion beobachtet.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130310
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  • 96
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    Synthesis and a crystal structure analysis of mixed bis(phosphino)methanide/phosphonium bis(methylide) complexes of nickel, palladium, and platinum (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 1145-1152 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthese und eine Kristallstrukturanalyse von gemischten Bis(phosphino)methanid/Phosphonium-bis(methylid)-Komplexen des Nickels, Palladiums und PlatinsAus den Bis(diphenylphosphino)methanid-Komplexen des Typs {[(C6H5)2P]2CH}2M (M = Ni, Pd, Pt) und der äquivalenten Menge eines Ylids R2(CH3)P = CH2 (R = CH3, C2H5) wurden die drei Titelverbindungen {[(C6H5)2P]2CH}M[(CH2)2PR2] (5a - c) erhalten. Eine Röntgenbeugungsanalyse der Platinverbindung 5c ergab eine gemischte Chelatstruktur mit einem ebenen Bis(phosphino)methanid- und einem gefalteten Ylidring. Das mittlere C-Atom des Bis(phosphino)methanids unterhält keine direkten Kontakte zum Metall. Seine Abstände zu den P-Atomen deuten erheblichen Doppelbindungscharakter an. Ylidischer Doppelbindungscharakter wird auch in der Phosphonium-bis(methylid)-Gruppe beibehalten.
    Notes: From bis(diphenylphosphino)methanide complexes of the type {[(C6H5)2P]2CH}2M (M = Ni, Pd, Pt), and an equivalent amount of an ylide R2(CH3)P = CH2 (R = CH3, C2H5), the three title complexes {[(C6H5)2P]2CH}M[(CH2)2PR2] (5a - c) have been prepared. CH2[P(C6H5)2]2 is the by-product of the reaction. An X-ray diffraction study of the platinum compound 5c revealed a mixed chelate structure with a planar bis(phosphino)methanide and a folded ylide ring. The central carbon of the bis(phosphino)methanide is not in close contact with the metal. Its distances to the phosphorus atoms indicate significant double bond character, some of which is also retained in the phosphonium bis(methylide) group.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130335
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  • 97
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    The structures of S4N5⊖, S4N5⊕, and S5N6. A rationalization based upon molecular orbital theory (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 1138-1144 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Die Strukturen von S4N5⊖, S4N5⊕, and S5N6. Eine Erklärung mit Hilfe der Molekül-Orbital-TheorieMit Hilfe qualitativer Argumente aus der Molekül-Orbital-Theorie können die wesentlichen Merkmale der Strukturen von S4N5⊖, S4N5⊕, and S5N6 erklärt werden. Mögliche entartete Umlagerungen aller drei Strukturen werden diskutiert. Eine Erweiterung des vorgeschlagenen Modells erklärt die Strukturen von As4S5 und β-P4S5.
    Notes: Using qualitative arguments from molecular orbital theory the essential features of the structures of S4N5⊖, S4N5⊕, and S5N6 can be rationalized. Possible degenerate rearrangements of all three species are discussed. An extension of the presented model allows also the understanding of the structures of As4S5 and β-P4S5.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130334
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  • 98
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    Aufbau von Pregnan-Seitenketten (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 1184-1188 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis of Pregnane Side ChainsThe adduct 2, formed by addition of methyl lithiomethoxyacetate to the androstane derivative 1, is transformed via key intermediate 4 into various pregnanes with pharmacologically interesting side chains.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130338
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  • 99
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    Notiz über die Synthese des Cinalbicols (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 1189-1191 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Note on the Synthesis of CinalbicolThe rearranged sesquiterpene phenol (10) is synthesized starting from a suitable diene adduct in five steps.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130339
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  • 100
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    Übergangsmetall-substituierte Phosphane, Arsane und Stibane, XXI. Dicarbonyl(η5-cyclopentadienyl)(dimethylarsenido)eisen und μ-(Dimethylarsonio)-bis[dicarbonyl(η5-cyclopentadienyl)eisen]-chlorid (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 1180-1183 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Transition Metal Substituted Phosphanes, Arsanes and Stibanes, XXI. Dicarbonyl(μ5-cyclopentadienyl)(dimethylarsenido)iron and μ-(Dimethylarsonio)-bis[dicarbonyl(μ5-cyclopentadienyl)iron] ChlorideCp(CO)2FeAsMe2 (1) is obtained in moderate to good yields by the reaction of Me2AsCl with Kat[Fe(CO)2Cp] (Kat = Na, MeP(n-Bu)3) together with [Me2As]2 and the arsonium chloride {[Cp(CO)2Fe]2AsMe2}Cl (2). For the salt-like product the mechanism of formation is proved. 1 is generated in quantitative yield via transmetallation of Cp(CO)3Mo - AsMe2 with [Cp(CO)2Fe]Na.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130337
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