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  • Organic Chemistry  (669)
  • Life and Medical Sciences  (486)
  • 1980-1984  (1,155)
  • 1940-1944
  • 1980  (1,155)
Collection
Keywords
Publisher
Years
  • 1980-1984  (1,155)
  • 1940-1944
Year
  • 1
    Electronic Resource
    Electronic Resource
    Masthead (1980)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1980) 
    Details
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010101
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  • 2
    Electronic Resource
    Electronic Resource
    Tubulin nucleation and assembly in mitotic cells: Evidence for nucleic acids in kinetochores and centrosomes (1980)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1980), S. 1-15 
    Details
    ISSN: 0886-1544
    Keywords: centrosomes ; kinetochores ; microtubule initiation ; nuclease enzymes ; electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A lysed cell system was used to study the organelle structure and nucleation of exogenous tubulin at kinetochores and centrosomes in mitotic PtK2 cells. We have used this lysed cell system in conjunction with nuclease digestion experiments to determine which specific nucleic acids (DNA or RNA) are involved in either the structure and/or microtubule-initiating capacity of kinetochores and centrosomes. The results indicate that DNase I specifically decondenses the kinetochore plate structure, with the eventual loss in the ability of the chromosomes to nucleate microtubule assembly. DNase I had no effect on either the structure or nucleating capacity of centrosomes. Both RNase T1 and RNase A specifically attacked the amorphous pericentriolar material of the centrosomes, with a concomitant loss in the ability of this material to nucleate microtubule formation. Neither RNase appeared to affect the structure or nucleating capacity of the kinetochore. Therefore, the two types of nucleases appear to exert preferential effects on the different types of microtubule initiation sites in mitotic mammalian cells. The results suggest that DNA is a major component of the kinetochore, while RNA is a major component of the amorphous pericentriolar material. These findings support the concept that microtubule initiation sites in mitotic cells contain nucleic acids which are essential for the structural and functional integrity of the sites.
    Additional Material: 45 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010102
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  • 3
    Electronic Resource
    Electronic Resource
    Redistribution of actin and fascin in sea urchin eggs after fertilization (1980)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1980), S. 31-40 
    Details
    ISSN: 0886-1544
    Keywords: actin ; fascin ; actin cross-linking proteins ; fertilization ; microvilli ; sea urchin eggs ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Following fertilization, the sea urchin egg cortex undergoes a structural change involving the assembly and organization of actin filaments into microvilli. Antifascin localizes this actin cross-linking protein in the microvilli of the fertilized egg cortex but no organized staining is present in the unfertilized cortex. Determination of the actin content of eggs using the DNAase I inhibition assay indicates that actin is about 1.4% of the total protein. Approximately 90% of this actin is soluble in low calcium isotonic extracts of unfertilized eggs while only 60-65% can be recovered in identical extracts of fertilized eggs. Similar measurements for fascin using a radioimmunoassay indicate this molecule represents about 0.3% of the total egg protein, essentially all of which is recovered in low calcium isotonic extracts of unfertilized eggs. After fertilization only 65-70% of this actin cross-linking protein is in the soluble phase. These results demonstrate a markedly different solubility for actin and fascin after fertilization, when the indirect immunofluorescence staining localizes fascin in the microvilli, and are consistent with the idea that fascin organizes newly polymerized actin filaments into the microvillar cores. A consideration of the amounts of actin and fascin incorporated into the cortex after fertilization and the number of microvilli on the egg surface indicates that the measured values are sufficient to account for the observed microvillar elongation.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010104
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  • 4
    Electronic Resource
    Electronic Resource
    Control by calcium of the contractility of Labyrinthula slimeways and of the translocation of Labyrinthula cells (1980)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1980), S. 17-29 
    Details
    ISSN: 0886-1544
    Keywords: Ca-ion ; Labyrinthula ; contraction ; glycerination ; Ca-reservoir ; cell movement ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Colonies of Labyrinthula, a colonial marine protist, expand by protrusive movements of the specialized slimeways. The movements recorded in time-lapse films are of two types - filopodial and lamellipodial - and occur at rates equivalent to those of cell translocation.Evidence is presented that Ca2+ regulates the contraction of the actomyosin system of filaments present in the slimeways of Labyrinthula. In glycerinated models or in colonies exposed to ionophore A23187 contraction is evidenced by the occurrence of periodic contractions of the slimeways, giving them the appearance of strings of beads. Glycerinated slimeways contract on the addition of Ca2+ and ATP while slimeways provided with ionophore A23187 contract on addition of Ca2+ alone. The concentration required is 1.1 × 10-7 M Ca2+ while concentrations of 6.2 × 10-8 or lower were ineffective. Rates of contraction were measured in time-lapse films which provide evidence that contractions and beading occur everywhere in the slimeway system. When beading occurs, the 6-nm filaments transform from an array of parallel single filaments into an interwoven meshwork.We have identified by pyroantimonate-OsO4 fixation, as possible Ca2+ reservoirs, deposits of Ca2+ in bothrosomes - structures through which cell secretions pass into the slimeways. The electron-dense deposits are located at the base of the bothrosome and disappear after incubation with EGTA. We propose that the translocation of cells as well as the movements of slimeways may be regulated by the cells through the local measured liberation of Ca2+ from the bothrosome where it is sequestered.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010103
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  • 5
    Electronic Resource
    Electronic Resource
    An analysis of spindle ultrastructure during anaphase of micronuclear division in Tetrahymena (1980)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1980), S. 41-61 
    Details
    ISSN: 0886-1544
    Keywords: mitosis ; mitotic spindle ; kinetochore ; microtubule ; micronucleus ; Tetrahymena ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Mitotic micronuclei were isolated from Tetrahymena thermophila and data on spindle ultrastructure were obtained from serial, transverse sections. Comparison of data from nuclei at meta- and early anaphase with data from nuclei at late anaphase showed that during anaphase, sister kinetochores move from the equator to the spindle poles, but kinetochore translocation occurs without any apparent change in either the number or length of kinetochore microtubules. This unprecedented result is ascribed significance with regard to the mechanism of kinetochore transport since there are only a limited number of ways that result could be achieved. The organization of the peripheral sheath changes during anaphase as evidenced by gaps in the sheath at late anaphase. Numerous kinetochore and non-kinetochore microtubules are located in polar regions of the spindle at late anaphase, whereas those regions contained only peripherally arranged microtubules at earlier stages. Tracking of individual kinetochore microtubules in late anaphase nuclei showed that some of them appeared to become incorporated into the peripheral sheath near the pole. At early and late anaphase, crossbridges connect adjacent microtubules throughout the spindle poleward to the kinetochores, as well as in the interzone.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010105
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  • 6
    Electronic Resource
    Electronic Resource
    Physarum myosin light chain binds calcium (1980)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1980), S. 63-71 
    Details
    ISSN: 0886-1544
    Keywords: Physarum polycephalum ; myosin light chains ; polyacrylamide gel electrophoresis ; calcium ; cytoplasmic streaming ; actomyosin ATPase regulation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Myosin from the slime mold Physarum polycephalum contains three sizes of polypeptides: a heavy chain and two light chains, LC-1 and LC-2. Using a simple qualitative test for calcium binding by comparing electrophoretic migration of the polypeptides in sodium dodecy1 sulfate (SDS) acrylamide gels in the presence and absence of calcium, we have found that Physarum myosin light chain LC-2 migrates with an apparent molecular weight of 16,900 daltons in the presence of the metal ion chelator ethylene glycol bis (B-aminoethyl ether) N,N′-tetraacetic acid (EGTA). However, if calcium chloride is added to the sample prior to electrophoresis, the apparent molecular weight decreases to 16,100. Lanthanide and cadmium ions, but not magnesium, can substitute for calcium. Because the ionic radii of Ca2+, La3+, and Cd2+ are almost identical, we conclude that Physarum myosin LC-2 possesses a very size-specific binding site for calcium. Physarum myosin LC-1 and the heavy chain give no evidence for binding calcium by this test. Since cytoplasmic streaming in the plasmodium of Physarum requires calcium, our evidence indicates that the calcium-binding property of Physarum myosin LC-2 may be important in regulating the production of force by actomyosin in the ectoplasm. Unexpectedly, the myosin light chain in Physarum capable of binding calcium, LC-2, is the essential light chain, while LC-1 is a member of the regulatory class of myosin light chains [V. T. Nachmias, personal communication]. Until now, essential myosin light chains have not been shown to have high affinity divalent cation binding sites. This means a new version of the myosin-based model for actomyosin regulation by calcium may be required to explain cytoplasmic movement in Physarum, and perhaps in other motile systems involving cytoplasmic myosins as well.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010106
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  • 7
    Electronic Resource
    Electronic Resource
    The role of the extracellular matrix in cell motility in fibroblast aggregates (1980)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1980), S. 99-112 
    Details
    ISSN: 0886-1544
    Keywords: cell motility ; extracellular matrix ; collagen ; glycosaminogly cans ; collagenase ; hyaluronidase ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The effect of specific components of the extracellular matrix on the motility of tissue cells was studied using organ-cultured aggregates of embryonic fibroblasts. Spherical aggregates of chick embryo heart and skin fibroblasts were fused with [3H]-thymidine-labeled aggregates of the identical cell type. The movement of labeled cells into the unlabeled partner aggregate served as an estimate of cell motility in the cultured tissue-like aggregates. Collagenase treatment decreased the collagen content of heart fibroblast aggregates and increased cell motility; ascorbic acid treatment increased the collagen content of skin fibroblast aggregates and decreased cell motility. Reduction of the glycosaminoglycan content with testicular hyaluronidase had no measurable effect on cell motility in heart fibroblast aggregates.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010108
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  • 8
    Electronic Resource
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    Identification of genetic elements associated with muscle structure in the nematode caenorhabditis elegans (1980)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1980), S. 73-97 
    Details
    ISSN: 0886-1544
    Keywords: nematodes ; muscle structure ; mutants ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A search for new mutants with altered body-wall muscle cell structure has been undertaken in the nematode C elegans. One-hundred seventeen mutants were isolated after mutagenesis with ethyl methanesulfonate or ultraviolet light, enrichment by a motility-requiring test, and screening by polarized light microscopy; 102 of these mutants were in ten previously established genes, whereas 15 mutants permitted the identification of seven new complementation groups in C elegans. Two of the new genes map on linkage group I (unc-94 and unc-95) and four genes are sex linked (unc-96, unc-97, unc-98, and unc-99). One complementation group (unc-100) could not be mapped because of the special characteristics of its cohort mutants. Representative mutants of the mapped genes were examined by polarized light and electron microscopy. All of the mutants exhibit disruptions of the normal A and I band organization of thick and thin filaments. Several of the mutants produce collections of thin filament-like structures. In one of these cases, HE177 demonstrated collections of somewhat wider, intermediate-sized filaments as well, and the HE195 mutant produces paracrystalline aggregates of thin filaments amidst looser arrangements of similar structures. The mutants in newly identified genes, as well as the new mutants in previously established genetic loci, have promise as tools in the study of myofibrillar assembly and function. Among the 22 complementation groups associated with body-wall structure in C elegans, it is likely that some genes code for regulatory and morphogenetic functions in addition to the well-studied structural, contractile, and calcium-associated proteins in muscle.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010107
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  • 9
    Electronic Resource
    Electronic Resource
    Tubulin content and synthesis in differentiating drosophila cells in culture (1980)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1980), S. 113-129 
    Details
    ISSN: 0886-1544
    Keywords: tubulin ; Drosophila ; β-ecdysterne ; differentiating ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Drosophila Kc cells exposed to physiological doses of the moulting hormone, β-ecdysone, elongate, become motile, and subsequently aggregate. This pattern of morphogenesis was found to require the assembly of a microtubular cytoskeleton. Tubulin content was significantly increased in hormone-treated cells when compared to controls, as measured by a 3H-colchicine-binding assay. However, determinations of rates of tubulin synthesis and breakdown revealed no difference between control and hormone-treated cells for either parameter. When tubulin content was assayed by methods that do not depend on colchicine-binding activity, no difference between hormone-treated and control cells was observed. These results are discussed in terms of a model in which β-ecdysone affects the distribution of tubulin in “assembly-active” and “assembly-inactive” pools.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010109
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  • 10
    Electronic Resource
    Electronic Resource
    Meeting report (1980)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1980), S. 159-162 
    Details
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010112
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  • 11
    Electronic Resource
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    The formation and elongation of filopodia during transformation of sea urchin coelomocytes (1980)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1980), S. 131-140 
    Details
    ISSN: 0886-1544
    Keywords: sea urchin coelomocytes ; motility ; filopodial formation and elongation ; ciné film analysis ; scanning electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Sea urchin coelomocytes were examined during their morphological transformation from petaloid to filopodial forms by scanning electron microscopy and ciné film analysis. Petaloid coelomocytes have a variable morphology but, in general, consist of numerous thin sheets of cytoplasm, the petals, arranged in three dimensions around a central nuclear region. The transition to the filopodial form can occur in either substrate-attached or suspended cells and begins with the formation of several microspikes at the edge of each petal. These become more apparent as the cytoplasm between each microspike/filopodium is retracted centripetally. Concomitantly, the diameter of the flattened cell is increased by as much as twofold as the filopodia actively lengthen at a uniform, average rate of 0.5 μm/minute. The transformation process requires ca 15 minutes and is complete when the cell diameter no longer increases. These filopodia are functionally distinct from the passively produced retraction fibers observed in cultured mammalian cells. The formation of filopodia is biphasic and includes both a cytoplasmic retraction phase and an active extension phase.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010110
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  • 12
    Electronic Resource
    Electronic Resource
    Invited review: Guidance cue patterns and cell migration in muiticeliuiar organisms (1980)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1980), S. 141-157 
    Details
    ISSN: 0886-1544
    Keywords: axon guidance ; chemotaxis ; haptotaxis substrate pathways ; development ; pattern biology ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In multicellular organisms, guidance cues are either diffusible molecules or cellular or extracellular surfaces that are found in reproducible locations and that orient migrating cells and cell processes. The pattern of the guidance cues usually determines the complex in vivo migration routes of motile cells and cell processes. Within organisms, guidance cues are found to be organized in two general patterns: (a) broad gradients - such as diffuse chemotactic gradients; (b) discrete routes (substrate pathways) - such as chemotactic gradients confined to long channels, and such as the axon surface which represents a long specific highway for migrating Schwann cells.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010111
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  • 13
    Electronic Resource
    Electronic Resource
    Announcement (1980)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1980), S. 163-163 
    Details
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010113
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  • 14
    Electronic Resource
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    Statement of purpose (1980)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1980), S. 167-167 
    Details
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010114
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  • 15
    Electronic Resource
    Electronic Resource
    The changes in sperm nuclei after penetrating fish oocytes matured without germinal vesicle material in their cytoplasm (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980), S. 121-132 
    Details
    ISSN: 0148-7280
    Keywords: sperm nucleus ; fish oocyte ; germinal vesicle (GV) ; nuclear formation ; chromosome ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The processes occurring from sperm penetration to chromosome formation in the cytoplasm of Oocytes matured in vitro, after removal of the germinal vesicle (GV) and before hormonal stimulation, were observed with electron microscope. The dechorionated oocytes, matured without the participation of the GV material, responded to sperm penetration by initiating a cortical reaction within 20 seconds after insemination. The pentrating sperm nuclei transformed to male pronuclei with vesiculation of the nuclear membrane, chromatin decondensation, and formation of a pronuclear membrane. Before cleavage, however, no chromosome formation was observed in these oocytes. Instead, the fully grown pronuclei change to a picnotic chromatin mass without or with an only fragmented nuclear membrane, then disappeared. On the contrary, sperm nuclei that penetrated into the cytoplasm of naked eggs containing GV material during maturation underwent pronuclear and chromosomal formation. Judging from these observation in Oryzias oocytes, the GV material seems to be unnecessary for the formation of pronucleus from the compact sperm nucleus, but is essential for the process of chromosomal formation.
    Additional Material: 9 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1120030204
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  • 16
    Electronic Resource
    Electronic Resource
    Sertoli-germ cell interrelations: A review (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980), S. 179-202 
    Details
    ISSN: 0148-7280
    Keywords: Sertoli cell ; spermatogenesis ; junction ; germ cell ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120030209
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  • 17
    Electronic Resource
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    Masthead (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980) 
    Details
    ISSN: 0148-7280
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120030301
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  • 18
    Electronic Resource
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    Actin filaments and mitochondrial movement in vertebrate spermiogenesis (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980), S. 203-209 
    Details
    ISSN: 0148-7280
    Keywords: actin ; mitochondrial movement ; spermiogenesis ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The presence of actin filaments around mitochondria during vertebrate spermiogenesis was demonstrated by immunofluorescence and immuno-electron microscopy and by heavy meromyosin decoration. The presence of actin is supposed to be related to mitochondrial rearrangements occurring in the spermatid stage.
    Additional Material: 9 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1120030302
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  • 19
    Electronic Resource
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    Role of cumulus cells for rat oocyte maturation and metabolism (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980), S. 133-140 
    Details
    ISSN: 0148-7280
    Keywords: rat oocytes ; maturation ; oxygen consumption ; cumulus cells ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Oocytes collected from immature PMSG-treated rats on the morning of proestrus were allowed to mature in culture either surrounded by their cumulus cells or after denudation. It was found that the time course of oocyte nuclear maturation was similar whether the cumulus cells were present or not. The oxygen consumption of noncultured oocytes was 0.12 nl/hr/oocyte and increased by 40% after four to eight hours in culture with intact cumulus. Respiration of oocytes cultured without cumulus remained constant throughout the culture, except for a transient decrease after four hours.It is concluted that the cumulus cells do not affect the spontaneous nuclear maturation in vitro, but that the metabolism in oocytes cultured with intact cumulus is different from that of cultured denuded oocytes. Furthermore, it appears that the rise in oocyte oxygen consumption is not a prerequisite for nucler maturation.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1120030205
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  • 20
    Electronic Resource
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    Immunocytochemical studies on the zona pellucida of cow blastocysts (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980), S. 141-148 
    Details
    ISSN: 0148-7280
    Keywords: cow blastocysts ; zona pellucida ; stability and location of antigenic material ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Labeling of the zona pellucida of cow blastocysts with zona-specific anti-serum shows that antigenicity is unaffected by abnormal cleavage, in vitro culture, or frozen storage. The uniform labeling in thin sections indicates that the zona pellucida is homogeneous antigenically. Heavier labeling of the inner and outer surfaces of the zona pellucida in thick sections appers to be due to greater porosity of these regions, in which the zona material becomes highly dispersed, or even partly solubilized, thereby permitting the formation of an antigen-antibody matrix.
    Additional Material: 12 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1120030206
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  • 21
    Electronic Resource
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    Identification and hormonal control of reproductive-tract-specific antigens present in rabbit oviductal fluid (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980), S. 169-177 
    Details
    ISSN: 0148-7280
    Keywords: oviduct ; oviductal fluid ; mucin ; steroids ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Utilizing the intra-abdominal flask technique to collect oviductal fluid, the presence of two or possibly three reproductive-tract-specific antigens have been observed in rabbit oviductal fluid. Two of these antigens may be accounted for by the two forms of uteroglobin. The other antigen has a molecular weight greater than 200,000 daltons and its concentration in oviductal fluid is under hormonal control. During pseudopregnancy (PSP), when progesterone concentrations are high, or upon progesterone administration, the concentration of this high molecular weight antigen doubles in oviductal fluid. This correlates well with the previously observed increase in release of secretory products from the oviductal epithelia.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1120030208
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  • 22
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    Ultrastructural studies of spermatogenesis in the anthocerotales. III. Gamete morphogenesis: From spermatogenous cell through midstage spermatid (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980), S. 149-167 
    Details
    ISSN: 0148-7280
    Keywords: Bryophyta ; Phaeoceros ; spermatid morphogenesis ; spermatogenesis ; ultrastructure ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: An ultrastructural examination of spermatogenesis in Phaeoceros has shown nucleoli to be present in spermatogenous cells and to persist until the centrioles become associated with nuclei of young spermatids. At the onset of multilayered structure (MLS) formation, well-defined aggregations of osmiophilic strands begin to form in the nuclei of young spermatids and disappear shortly after chromatin condensation starts in the midstage spermatids. When the centrioles in the young spermatids are orientated perpendicular to the nuclear envelope, the nucleoplasm immediately in front of them is densely stained. Where the spline tubules of the MLS extend over the nucleus, the nuclear envelope is devoid of pores, and the inner nuclear membrane is contacted internally by the local deposition of dense staining nucleoplasm. Chromatin condensation begins with strands extending perpendicularly from the dense staining nucleoplasm beneath the spline and continues with the nuclear beak becoming filled with condensed chromatin. As the MLS lamellae disappear acropetally, the rear portion of the anterior mitochondrion (AM) extends back under the nuclear beak which now narrows to a size that approximates the anterior end of the nucleus of a spermatozoid. By the end of the mid-spermatid stage, the nucleus has coiled approximately one gyre of a helix and the five or six central slpine tubules extend over the plastid which is now located beneath the front end of the AM. Several profiles of endoplasmic reticulum confluent with the nuclear envelope are present. Possible factors which might play a role in determining the morphology of the mid-spermatids are discussed.
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    A new procedure for rapidly scoring acrosome reactions of human sperm (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980), S. 211-216 
    Details
    ISSN: 0148-7280
    Keywords: acrosome ; human sperm ; lectin ; capacitation ; fertilization ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Because the acrosome of human sperm is too small to be directly visualized by phase-contrast microscopy, acrosome reactions (that is loss of the acrosome) are generally not evaluated in studies of human sperm capacitation and fertilization. Nevertheless, it would be useful in such studies to have a technique for easily identifying and quantitating acrosome-reacted sperm. In this paper, we describe a method for labeling the human sperm acrosome with fluorescein-conjugated Ricinus communis agglutinin-60 (FITC-RCA); we show that in sperm without acrosomal caps, FITC-RCA labeling occurs either not at all or only in the equatorial segment of the acrosome. To determine if the absence of FITC-RCA labeling in the acrosomal cap region gives a reliable estimate of acrosome reactions, washed sperm or sperm incubated in a capacitating medium (BWW) were divided into two groups, which were then fixed for FITC-RCA labeling or transmission electron microscopy. Counts of acrosome reactions made by each method were similar, and we observed an increase in the percentage of reactions following incubation in BWW. We conclude that the FITC-TCA labeling technique is a reliable method for accurately scoring the percentage of acrosome-reacted human sperm.
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    Masthead (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980) 
    Details
    ISSN: 0148-7280
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120030101
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    Effect of the inhibitors of ion movements, verapamil and tetraethylammonium, on fertilization of mouse eggs in vitro (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980), S. 1-7 
    Details
    ISSN: 0148-7280
    Keywords: mouse ; in vitro fertilization ; inhibitors of fertilization ; calcium ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Better than 75% fertilization of C57BL/6 mouse eggs with C57BL/6 sperm is obtained in vitro in a modified Kreb's-Ringer-bicarbonate medium containing 8 mM HEPES. No fertilization of obtained when Ca2+ is omitted from this medium. The drug verapamil, which interferes with Ca2+ channels and blocks the acrosome reaction [Schackmann et al, 1978] and fertilization in the sea urchin, also blocks fertilization of mouse eggs in vitro when included in complete medium at a concentration of 80 μg/ml. Tetraethylammonium, which inhibits delayed axonal potassium currents and prevents the acrosome reaction in sea urchin sperm, also completely inhibits fertilization of mouse eggs in vitro at a concentration of 5 mM. Tetramethylammonium, which does not inhibit potassium movements at the same concentration reduces fertilization by about 50%. The data are consistent with the hypothesis that ion movements are necessary for activation of the sperm and/or egg in mouse fertilization.
    Additional Material: 1 Ill.
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    Quantitation of avian spermatozoan motility: Neurochemical regulation (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980), S. 17-24 
    Details
    ISSN: 0148-7280
    Keywords: sperm ; motility ; neurochemical ; paraoxon ; acetylcholine ; cholinesterase ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The hypothesis that motility of avian sperm is regulated by acetylcholine was examined by treating rooster (Gallus domesticus) sperm with choline analogs and paraoxon, an inhibitor of colonesterases. Acetylcholine chloride (AChCl) was most effective, acetylthiocholine iodide and butyrylthiocholine iodide were less effective, and choline chloride was ineffective in stimulating sperm motility. Histochemical localization of cholinesterase activity with the electron microscope showed enzyme activity to be associated with membranes of the head and within fibrillar components of the tail. Increasing concentrations of paraoxon decreased cholinesterase activity and increased sperm motility. The data provide evidence that the motility of avian sperm, like that of mammal and sea urchins, may be regulated in part by a system with similarities to the cholinergic neurotransmitter system.
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    Artificial fertilization of gametes from the South African clawed frog, Xenopus laevis (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980), S. 45-57 
    Details
    ISSN: 0148-7280
    Keywords: clawed frog ; egg ; fertilization ; jelly coat ; motility ; sperm ; Xenopus laevis ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A reproducible and effective method for fertilization eggs of Xenopus laevis was developed based of systematic manipulation of environmental factors. The effects of varying concentrations of individual components of a fertilization medium were tested by measuring jelly swelling, sperm motility, and sperm longevity. Results were used to develop an improved medium for fertilization, consisting of 41.25 mM NaCl, 1.25 mM KCl, 0.25 mM CaCl2, 0.0625 mM MgCl2, 0.5 mM Na2HPO4, 2.5 mM HEPES, 1.9 mM NaOH, final pH(2°) 7.8.
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    Initiation, prolongation, and reactivation of the motility of salmonid spermatozoa (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980), S. 247-257 
    Details
    ISSN: 0148-7280
    Keywords: spermatozoa (salmonid) ; adenosine triphosphate (ATP) in sperm motility ; cyclic adenosine monophosphate (cAMP) in sperm motility ; reactivation of trout sperm motility ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The motility of salmonid spermatozoa initiated by dilution of the milt with ovarian fluid or isotonic saline is brief duration; it was believed that it can be activated only once in the life of the spermatozoon. Dilution of the milt with an equal volume of isotonic saline (0.12 M-NaCl) containing 5 mM-3-isobutyl-1-methylxanthine (MIX) prolonged and intensified sperm motiliy. When motility had stopped after initial mobilization with saline or ovarian fluid, it could be reactivated by addition of MIX; reactivated spermatozoa fertilized eggs. Dilution with saline containing K+ (24 mEq/liter) did not initiate sperm motility even in the presence of MIX. The spermatozoa were mobilized by subsequent with 0.12 M-NaCl. The concentration of adenosine triphosphate (ATP) in sperm suspensions dropped on dilution with saline and rose as motility ceased, but declined without subsequent recovery following dilution with MIX-saline. The concentration of cyclic adenosine monophosphate (cAMP) rose and fell sharply on initiation of motility and rose again after motility had declined. While salmonid spermatozoa can be mobilized by dilition with saline alone, the effectiveness of MIX in reactivating “spent” spermatozoa supports the assumption that cAMP plays a role in the initiation of sperm motility.
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    Ovoperoxidase activity in ionophore treated mouse eggs. II. Evidence for the enzyme's role in hardening the zona pellucida (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980), S. 279-290 
    Details
    ISSN: 0148-7280
    Keywords: ovoperoxidase ; zona hardening ; zona pellucida ; mouse eggs ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: One consequence of fertilization or parthenogenetic activation of mammalian eggs is an altaration in the solubility proprieties of the zona pellucida, known as zona hardening. Several lines of evidence indicate that an ovoperoxidase, which is activated and/or secreted from mouse eggs. Following parthenogenetic activation, corss-links tyrosine residues in the zona pellucida and results in hardening of the zona. First, zona hardening, as determined by decreased solubility of the zona in pronase, is inhibited by several compounds known to inhibit peroxidases. Inhibitors of hardening include phenylhydrazine, sodium sulfite, sodium azide, and glycine ethyl ester. Second, tyrosine analogs inhibit zona hardening, unless the phenolic hydroxyl group or ortho position is blocked. That is, O-methyltyrosine (methyl substitution of phenolic hydroxyl) does not inhibit hardening; o-methyltyrosine (methyl substitution of one ortho position) partially inhibits, whereas tyramine and N-acetyltyrosine (free hydroxyl and ortho positions) effectively block hardening. Finally, exogenous horseradish peroxidasepromotes limited hardening of the zona in unactivated eggs. These results are consistent with a peroxidase catalyzed cross-linking of tyrosines in the zona that results in hardening of the zona pellucida.
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    Fragmentation of condensed chromatin in nuclei of a plant sperm, pteridium aquilinum (L.) Kuhn (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980), S. 291-298 
    Details
    ISSN: 0148-7280
    Keywords: condensed chromatin ; sperm ; Pteridium ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Nuclei of pteridium sperm have been dispersed by turbulence in natural or slightly alkaline buffer after stripping off the cytoplasm with nonionic detergent. The nuclei tended to break up into fragments arranged in a linear order. These fragments fluoresced brightly with acridine orange as did intact nuclei. Grounds are given for identifying the smaller fragments with chromosomes. It is proposed that the sperm nucleus of British Pteridium, possibly an autotetrapolid, consists of a sequence of paired homologues.
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    Announcement (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980), S. 307-307 
    Details
    ISSN: 0148-7280
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120030315
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    The spermatozoon. Don W. Fawcet and J. Michael Bedford, eds. Urban and Schwarzenberg, Baltimore-Munich, 1979. 40 illustrted chapters. 441 pages. $49.00 (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980), S. 305-306 
    Details
    ISSN: 0148-7280
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120030314
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    Partial activation of sea-urchin eggs by bonellin (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980), S. 309-316 
    Details
    ISSN: 0148-7280
    Keywords: fertilization ; membrane potential ; bonellin ; amino acid incorporation into proteins ; DNA synthesis ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We here describe further studies on the action of bonellin on sea-urchin eggs. Bonellin brings about Some of the changes that are known to occur in the egg upon fertilization. In particular, it appears to cause the increased rate of incorporation of amino acids into proteins, the increase of the voltage noise, and the exocytosis of some of the cortical granules. A comparison with the effect of ammonia is discussed.
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    Ultracytochemical localization of 3β-hydroxy-steroid ferricyanide reductase activity in the fetal mouse ovary (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980), S. 323-328 
    Details
    ISSN: 0148-7280
    Keywords: female meiosis ; estrogen synthesis ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: It has been suggested that the production of estrogens by the fetal ovary may modulate the entry or progression of meiosis in the female mammalian fetus. In the present study the possibility that the site of this steroid synthesis is the rete ovarii system was explored in the fetal mouse of gestational ages 12.5 to 18 days. The method of ultracytochemical localization of 3β hydroxy-steroid ferricyanide was used. Reaction product was found in the cytoplasm of the rete ovarii (prefollicular) cells as early as day 14 with increasing amounts seen at later gestational ages. The presence of this essential enzyme system in cells closely applied to oogonia and oocytes during an active meiotic period must be considered in developing concepts of meiotic entry.
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    Decondensation of sperm nuclei of australian marsupials: Effects of air drying and of calcium and magnesium (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980), S. 351-367 
    Details
    ISSN: 0148-7280
    Keywords: marsupial ; spermatozoa ; nucleus ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Spermatozoa of six species of Australian marsupials have been studied. The nucleus is highly unstable when compared with those of eutherian mammals. When thin films of spermatozoa in buffered saline are air-dried on glass slides, the nucleus disintegrates and flattens, leaving the acrosome, midpiece, and tail intact. This spreading of the nucleus can be inhibited by seminal plasma proteins and by bovine serum albumin, but is potentiated by detergents. The nucleus also decondenses spontaneously in the presence of high concentrations (〉0.25M) of calcium and magnesium salts, leaving the head membranes, acrosome, midpiece, and tail intact. This is inhibited by EDTA. In some species, certain areas of the nucleus appear more resistant t o Ca++/Mg++ treatment, and the initial stages of decondensation are uneven. Ultrastructurally the Ca++/Mg++ dispersed chromatin shows a moderately fine, branching, fibrillar structure, interspersed with dense granules. Treatment with disulphide bond cleaving agents together with detergents results in rapid and complete dispersal of the chromatin and acrosome, and slow digestion of midpiece and tail structures. Treatment with HCl, NaCl, KCl, EDTA, detergents, and sucrose has no effect on nuclear integrity, but treatment with NaOH (0.9-1.0M) results in complete digestion of the whole sperm. These findings are discussed in the light of evolutionary differences between marsupial and eutherian mammals in terms of sperm structure and composition.
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    Comparative ultrastructure of the yolk material in preimplantation stages of the hamster, mouse, and rat embryos (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980), S. 369-377 
    Details
    ISSN: 0148-7280
    Keywords: yolk ; preimplantation embryo ; ultrastructure ; hamster ; mouse ; rat ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Yolk material of preimplanation stages of embryos of the hamster, mouse, and rat were examined by a standardized electron microscopical procedure. The material was encountered as fibrils, scattered more or less densely in the cytoplasm. In the hamster, the material was present in large masses and the fibrils had a chain-like appearance when cut longitudinally. The ultrastructure of the fibrils was compatible with a helical pattern. The fibrils had a width of about 40 nm and the pitch (the axial distance of the repeating unit) was about 30 nm. In the mouse, the yolk material was dispersed in the cytoplasm forming small plaque-like groups. Also, in this species the fibrils were chain-like but smaller than in the hamster. The fibrils were often closely situated, resulting in images with varying crystalline appearances. In the rat, the yolk appeared as light areas occupying a substantial part of the cytoplasm. The fibrils in the yolk plaques were sparse and diffusely outlined. They were thinner than the fibrils of the mouse-yolk material, did not display any helical pattern at the resolution used, but showed a periodicity.
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    Announcement (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980), S. 405-406 
    Details
    ISSN: 0148-7280
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120030411
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    Properties of the first and second factors released after hamster sperm make contact with the zona pellucida prior to fertilization in vitro (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980), S. 395-403 
    Details
    ISSN: 0148-7280
    Keywords: sperm-zona contact ; fertilization ; peptides ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: An investigation was made as to the nature of two of the factors, termed S1, released within the first 30 minutes after contact is made between capacitated hamster sperm and the zona pellucida in vitro. Previous studies showed that these S1 factors were detected two and 20 to 25 minutes after the gametes were combined and that, based on filtration studies, the former possessed a molecular weight of less than 5,000 daltons. The present results show that the quantity of the 20-25-minute S1 factor released into the supernatant increased linearly as a function of the sperm concentration. This factor passed unimpeded through a filter with a 5,000 molecular weight cutoff but only 42% of the activity traversed a filter with a cutoff of 2,000 daltons. The two-minute S1 factor, in the virtual total absence of cells, was stable for 10 to 15 minutes, but lost significant activity upon longer incubation. Under the same conditions, the 20-25-minute factor lost approximately 25% of its activity within 15 minutes, but remained stable at this level for at least 45 minutes of incubation. Both S1 factors were not affected by a mixture of glycosidases, but were inactivated by subtilisin, trypsin, and leucine aminopeptidase which was contaminated with endopeptidases. The activity of the two-minute S1 factor appeared more susceptible to the action of the proteases than that of the 20-25-minute S1 factor. In contrast to previous results obtained with the two-minute S1 factor, the release of the 20-25-minute S1 factor was not inhibited by the inclusion of soybean trypsin inhibitor a t concentrations which are known to inhibit penetration of the zona by the sperm. The results suggest that the two- and 20-25-minute S1 factors are peptides which are not identical.
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    Zur Selbstkondensation von (β-Alkoxycarbonylalkyliden)-ammoniumsalzen (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 394-402 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Self-condensation of (β-Alkoxycarbonylalkylidene)ammonium SaltsIminium chlorides or trifluoroacetates of type 2, formed by protonation of β-(alkoxycarbonyl)-enamines 1, have been proved to undergo condensation to give derivatives of 4-alkyl-2-amino-6-hydroxybenzoic acid 6 via elimination of ammonium salt and alcohol. The structures of 6 had been established by spectroscopic data as well as by further reactions. The range of application of this condensation reaction has been studied and the mechanism is discussed. In the primary step presumably a nucleophilic attack on the alkoxycarbonyl group of the iminium salt 2 takes place by the enamine 1 present in the equilibrium. Analogous reactions are also found for homologues of the enamine 1 (e.g. 11, 13 and 17) to give the condensation products 12, 14, 15, and 20.
    Notes: Durch Protonierung von β-(Alkoxycarbonyl)enaminen 1 gebildete Iminiumchloride oder -trifluoracetate 2 kondensieren unter Abspaltung von Ammoniumsalz und Alkohol zu Derivaten der 4-Alkyl-2-amino-6-hydroxybenzoesäure 6, deren Strukturen spektroskopisch und durch Umsetzungen gesichert werden. Die Anwendungsbreite der Reaktion wird ermittelt und ihr Mechanismus diskutiert. Vermutlich wird primär das Iminiumsalz 2 von dem mit ihm im Gleichgewicht vorliegenden Enamin 1 nucleophil an der Alkoxycarbonylgruppe angegriffen. Analog reagieren auch homologe Enamine von 1, beispielsweise 11, 13 und 17 zu den Kondensationsprodukten 12, 14, 15 und 20.
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    Thermolyse ortho-chlorsubstituierter 1,2-Diarylethylendiamine (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 409-415 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thermolysis of ortho-Chloro-Substituted 1,2-DiarylethylenediaminesOn heating bis(2,6-dichlorophenyl)ethylenediamines 1a - d give indoles and  -  in the case of the racemates 1b and d  -  tetrahydroindoloindoles. The d,1-form of the corresponding 2,4-dichloro compound 1f leads to a 2,4,5-triarylimidazolidine, the meso-form 1e to an aziridine, whose formation via a 2,cis-4,5-triarylimidazolidine appears likely from mechanistic considerations.
    Notes: Die Bis(2,6-dichlorphenyl)ethylendiamine 1a - d reagieren bei der Thermolyse zu Indolen und im Falle der Racemate 1b und d auch zu Tetrahydroindoloindolen. Die d,1-Form der entsprechenden 2,4-Dichlorverbindung 1f führt zu einem 2,4,5-Triarylimidazolidin, die meso-Form 1e zu einem Aziridin, dessen Bildung über ein 2,cis-4,5-Triarylimidazolidin durch mechanistische Betrachtungen wahrscheinlich gemacht werden konnte.
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    Ligandstruktur und Komplexierung, LIII. Nichtcyclische Neutralliganden mit zwei zentralen Pyridin-Einheiten und starren Donorendgruppen (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 512-517 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Ligand Structure and Complexation, LIII1).  -  Non-cyclic Neutral Ligands with Two Central Pyridine Units and Rigid Donor End GroupsThe synthesis and properties of the title compounds, which are rendered comparatively rigid by the two pyridine rings, are described. Their complexation with alkali, alkaline earth and transition metal ions is examined. The crystalline complexes often contain stoichiometric amounts of water. 1H-NMR spectra show that helical ligand conformations are present in solutions of the complexes.  -  Neutral molecules like urea and thiourea are also shown to form stoichiometric complexes with the new ligands.
    Notes: Synthese und Eigenschaften der durch zwei Pyridinringe versteiften Titelverbindungen werden beschrieben. Ihre Komplexierung mit Alkali-, Erdalkali- und übergangsmetallionen wird unter-sucht. Die kristallinen Komplexe enthalten häufig stöchiometrische Mengen Wasser. Die 1H-NMR-Spektren zeigen, daß in Lösungen der Komplexe helikal gewundene Ligandkonformationen vorliegen.  -  Mit Neutralmolekülen wie Harnstoff und Thioharnstoff wurden gleichfalls stöchiometrische Komplexe isoliert.
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    Biologisch aktive Glykoside aus Asteroidea, I. Strukturen eines neuen Cerebrosidgemischs und von Nucleosiden aus dem Seestern Acanthaster planci (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 653-668 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Biologically Active Glycosides from Asteroidea, I1).  -  Structures of a New Cerebroside Mixture and of Two Nucleosides from the Starfish Acanthaster planciFrom the starfish Acanthaster planci the new cerebroside mixture 1 (11.7 mg per individual of average weight 150 g) and the two nucleosides 2 (2.4 mg per individual) and 3 (1.1 mg per individual) have been isolated. Acid catalyzed methanolysis of 1 afforded the methyl esters of four α-hydroxy fatty acids [tetracosanoate (major component), tricosanoate, docosanoate, and nonadecanoate], two 2-amino-1,3,4-alkanetriols [heptadecanetriol (major component) and octadecanetriol], and methyl glucoside. The nucleosides 2 and 3 have been identified as thymine deoxyribonucleoside and uracil deoxyribonucleoside, respectively. Apart from conventional analytical methods, field desorption mass spectrometry (FD-MS) was successfully used for the first time for the determination and confirmation of the structures of naturally occurring glycolipids and nucleosides.
    Notes: Aus dem Seestern Acanthaster planci wurden das neue Cerebrosidgemisch 1 (11.7 mg pro Individuum bei einem mittleren Körpergewicht von 150 g) sowie die beiden Nucleoside 2 (2.4 mg pro Individuum) und 3 (1.1 mg pro Individuum) isoliert. Die säurekatalysierte Methanolyse von 1 ergab die Methylester von vier α-Hydroxyfettsäuren [Tetracosanoat (Hauptbestandteil), Tricosanoat, Docosanoat und Nonadecanoat] zwei 2-Amino-1,3,4-alkantriole [Heptadecantriol (Hauptbestandteil) und Octadecantriol] sowie Methylglucosid. Die Nucleoside 2 und 3 wurden als Thymindesoxyribonucleosid bzw. Uracildesoxyribonucleosid identifiziert. Neben den konventionellen analytischen Methoden wurde erstmals die Felddesorption-Massenspektrometrie (FD-MS) für die Bestimmung und Absicherung der Struktur natürlich vorkommender Glykolipide und Nucleoside erfolgreich eingesetzt.
    Additional Material: 8 Ill.
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    Cycloadditionen von α-Chloralkylidenamin-oxiden an Hetero-ene, I; Carbonylverbindungen (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 686-692 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cycloaddition Reactions of α-Chloroalkylideneamine Oxides with Hetero-enes, I; Carbonyl CompoundsCycloaddition reaction of N-(2-chloroethylidene)cyclohexylamine oxide (2) with the hetero-enes 1a - 1f at 10°C in the presence of AgBF4 in 1,2-dichloroethane as solvent furnishes the reactive, dipolar intermediate iminium salts 3a - 3f. Subsequent reduction of 3a - 3f in water by NaBH4 yields the substituted 1,3-dioxa-4-azacyclohexanes 4a - 4f. From the bicyclic “hetero-ene” camphor (5) and from cholestanone (8) the spirocyclic compounds 7 and 9 have been obtained in an analogous way.  -  On the other hand, reaction of the hetero-enes 1c, 1e, 1f, and cyclododecanone (11) with 2 in the presence of AgBF4 give the iminium salts 3c, 3e, 3f and 12 which, in aquous 10% KCN solution, yield the nitriles 10a - 10c and 13 as mixtures of their isomers.
    Notes: Durch Cycloaddition des aus N-(2-Chlorethyliden)cyclohexylamin-oxid (2) in Gegenwart von AgBF4 in 1,2-Dichlorethan bei -10°C entstehenden reaktiven dipolaren Zwischenprodukts an die Hetero-ene 1a - 1f sowie anschließende reduktive Behandlung der Iminiumsalze 3a - 3f mit NaBH4 in Wasser entstehen die substituierten 1,3-Dioxa-4-azacyclohexane 4a - 4f; aus dem bi-cyclischen “Hetero-en” Campher (5) und aus Cholestanon (8) werden in analoger Weise die spiro-cyclischen Verbindungen 7 bzw. 9 erhalten.  -  Andererseits werden aus 1c, 1e, 1f sowie aus Cyclododecanon (11) mit 2 in Gegenwart von AgBF4 und anschließender Reaktion der Iminiumsalze 3c, 3e, 3f bzw. 12 mit 10proz. wäßriger KCN-Lösung die Nitrile 10a - 10c sowie 13 als Isomerengemische synthetisiert.
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    Synthese heteroaromatisch substituierter Harnstoffe und Chlorformamidine (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 693-698 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of Heteroaromatic Substituted Ureas and ChloroformamidinesCurtius degradation of heteroaromatic carbonyl azides leads to isocyanates, which react with amines to give the trisubstituted ureas 1. Some of these can be converted into the corresponding chloroformamidines 2 by chlorination with CCl4/(C6H5)3P.
    Notes: Der Curtius-Abbau heteroaromatischer Carbonsäureazide führt zu Isocyanaten, die mit sekundären Aminen zu den trisubstituierten Harnstoffen 1 reagieren. Einige dieser Harnstoffe können durch Chlorierung mit CCl4/(C6H5)3P in die entsprechenden Chlorformamidine 2 übergeführt werden.
    Additional Material: 2 Tab.
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  • 45
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    Herstellung bi- und tricyclischer Pyrrol-SystemeHerrn Prof. Dr. Dr. h. c. R. Huisgen in freundschaftlicher Verbundenheit zum 60. Geburtstag gewidmet. (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 703-714 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation of Bi- and Tricyclic PyrrolesHerrn Prof. Dr. Dr. h. c. R. Huisgen in freundschaftlicher Verbundenheit zum 60. Geburtstag gewidmet.Phthalimidoalkane-1,4-diones smoothly react with aromatic and aliphatic amines to give the substituted (phthalimidoalkyl)pyrroles 1 - 16. Hydrazinolysis of these compounds yields tricyclic 4H-pyrrolo[1,2-a][1,4]benzodiazepines 17 - 23 and bicyclic pyrrolo[1,2-c]imidazoles 24, 25, pyrrolo[1,2-c]pyrimidines 26, 27, pyrrolo[1,2-a]pyrazines 28 - 30, and pyrrolo[2,1-d][1,4]diazepines 31, 32, respectively.
    Notes: Phthalimidoalkan-1,4-dione lassen sich leicht mit aromatischen und aliphatischen Aminen zu substituierten (Phthalimidoalkyl)pyrrolen 1 - 16 umsetzen; die anschließende Hydrazinolyse der Produkte liefert die tricyclischen 4H-Pyrrolo[1,2-a][1,4]benzodiazepine 17 - 23 bzw. die bicyclischen Pyrrolo[1,2-c]imidazole 24, 25, Pyrrolo[1,2-c]pyrimidine 26, 27, Pyrrolo[1,2-a]pyrazine 28 - 30 und Pyrrolo[2,1-d][1,4]diazepine 31, 32.
    Additional Material: 3 Tab.
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  • 46
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    Additionen von Organozink verbindungen an C = C-Bindungen, III. Anlagerung von Bis(2-methylallyl)zink an para - an meta substituierte Styrole (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 736-743 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Addition of Organozinc Compounds to C = C-Bonds, III1).  -  Addition of Bis(2-methylallyl)zinc to para- and meta-Substituted StyrenesA Hammett correlation between the ratio of M → Cprim/M → Csec addition and the substituent constants s̰+ has been found for the addition of bis(2-methylallyl)zinc (1) to p- and m-substituted styrenes 2 - 8. Electron donating substituents favour M → Cprim addition, electron withdrawing substituents M → Csec addition.
    Notes: Für die Addition von Bis(2-methylallyl)zink (1) an p- und m-substituierte Styrole 2 - 8 wurde eine Hammett-Beziehung zwischen dem Verhältnis von M → Cprim/M → Csek-Addition und den Substituentenkonstanten s̰+ gefunden. Elektronenabgebende Substituenten begünstigen die M → Cprim-Addition, elektronenanziehende Substituenten die M → Csek-Addition.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/jlac.198019800513
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  • 47
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    Reaktionen von Nickelocen mit Organomagnesiumverbindungen und Bildung von η3-Allyl-η5-cyclopentadienylnickel-Komplexen (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 744-753 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Nickelocene with Organomagnesium Halides and Preparation of η3-Allyl-η5-cyclopentadienylnickel ComplexesNickelocene (1) reacts in ether/THF (ca. 5:1) with the 2-alkenylmagnesium compounds 2 - 5 and 11 in a molar ratio Ni/Mg - R = 1 to give the η3-allyl-η5-cyclopentadienylnickel complexes 6 - 9 and 12. Analogous compounds 14 - 19 are formed by the reaction of isopropyl- or isobutylmagnesium halide and 1,3-dienes with 1. Mixtures of isomeric allyl complexes are formed in the reaction of unsymmetrically substituted 1,3-dienes. The mixtures of syn-anti isomers equilibrate at 90°C. At 120°C an equilibration between the allylic isomers occurs.
    Notes: Nickelocen (1) reagiert in Ether/THF (ca. 5:1) mit den 2-Alkenylmagnesiumverbindungen 2 - 5 und 11 im Molverhältnis Ni/Mg - R = 1 glatt zu den η3-Allyl-η5-cyclopentadienylnickel-Komplexen 6 - 9 und 12. Analoge Verbindungen 14 - 19 entstehen bei gleichzeitiger Einwirkung von Isopropyl- oder Isobutylmagnesiumhalogeniden und 1,3-Dien auf 1. Mit unsymmetrisch substituierten 1,3-Dienen entstehen Mischungen isomerer Allylkomplexe, die beim Erhitzen auf 90°C in Gleichgewichtsgemische der syn-anti-Isomeren und bei 120°C in solche der Allyl-Isomeren übergehen.
    Additional Material: 7 Tab.
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  • 48
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    1,2-Naphthochinon-Derivate aus Kulturen des Mycosymbionten der Flechte Trypethelium eluteriae (Trypetheliaceae) (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 779-785 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 1,2-Naphthochinon-Derivate from Cultures of the Mycosymbiont from the Lichen Trypethelium eluteriae (Trypetheliaceae)From cultures of the mycosymbiont of the tropical cortical lichen Trypethelium eluteriae Sprengel the antibiotically active 1,2-naphthoquinones trypethelone (2), trypethelone methyl ether (3), 8-methoxytrypethelone methyl ether (5), and 4′-hydroxy-8-methoxytrypethelone methyl ether (6) have been isolated. The substitution pattern of these new derivatives of (+)-dunnione (1) is in accord with a polyketide biogenesis of the quinone system.
    Notes: Aus Kulturen des Mycosymbionten der tropischen Rindenflechte Trypethelium eluteriae Sprengel wurden die antibiotisch aktiven 1,2-Naphthochinone Trypethelon (2), Trypethelon-methylether (3), 8-Methoxytrypethelon-methylether (5) und 4′-Hydroxy-8-methoxytrypethelon-methylether (6) isoliert. Es handelt sich um Derivate des (+)-Dunnions (1), deren Substituentenanordnung mit einer Polyketidbiogenese des Chinonsystems im Einklang ist.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/jlac.198019800517
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  • 49
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    Synthesis of Isomeric N-Benzyl Derivatives of 1,2-Propanediamine (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 786-790 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthese isomerer N-Benzylderivate des 1,2-PropandiaminsBenzaldehyd reagiert mit der 1-Aminogruppe des 1,2-Propandiamins viel leichter zur Schiffschen Base als mit der 2-Aminofunktion. Dieser Unterschied ermöglicht die Synthese aller isomeren Mono-sowie Dibenzylderivate von racemischem und chiralem 1,2-Propandiamin (Schema 1, Tabelle 1).
    Notes: Benzaldehyde reacts with the 1-amino group of 1,2-propanediamine (1) to give a Schiff base much more readily than with the 2-amino group. This difference permits synthesis of all the isomeric mono- and dibenzyl derivatives of racemic and chiral 1,2-propanediamine (Table 1, Scheme 1).
    Additional Material: 1 Ill.
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    Oxidative Umlagerung von α-Benzylidenketonen mit Thallium(III)-nitrat in Methanol (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1283-1295 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Oxidative Rearrangement of α-Benzylideneketones with Thallium(III) Nitrate in MethanolSterically unhindered arylidene- and diarylideneacetones 1 or 2 having electron releasing aryl groups yielded with thallium(III) nitrate in methanol β-ketoacetals 3, 4 and 5, respectively. Electronegatively substituted 1f and sterically hindered 1g and 1h gave the 4-arylcrotonic esters 7 and by-products, while 1,3-dibenzylidenacetone (2a) yielded besides the expected products also the branched acetal esters 13a and 13b. Formation of the anomalous products 7 and 13 can be rationalized assuming a common cyclopropanone type intermediate.
    Notes: Sterisch unbehinderte Aryliden- und Diarylidenacetone 1 bzw. 2 mit elektronenspendenden Aryl-gruppen liefern mit Thallium(III)-nitrat in Methanol die β-Ketoacetale 3, 4 bzw. 5. Das elektronegativ substituierte 1f sowie die sterisch gehinderten Acetonderivate 1g und 1h ergeben die 4-Arylcrotonsäureester 7 und Nebenprodukte, während aus 1,3-Dibenzylidenaceton (2a) neben den erwarteten Produkten auch die verzweigten Acetalester 13a und 13b entstehen. Für die Bildung der anomalen Produkte 7 und 13 wird als gemeinsames Zwischenprodukt ein Cyclopropanonderivat vorgeschlagen.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/jlac.198019800812
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    Masthead (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980) 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198019800901
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    Dimere Naphthochinone, IV. Synthese von Biramentaceon, Mamegakinon und Rotundichinon (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1321-1347 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Dimeric Naphthoquinones, IV1).  -  Synthesis of Biramentaceone, Mamegakinone and RotundiquinoneMamegakinone (8a), biramentaceone (12a), 3,3′-bijuglone (8b), 2,2′-bijuglone (12b) and their methyl ethers were prepared by oxidative coupling of substituted 4-methoxy-1-naphthols; indigoids like 24 are intermediates. Cooxidation of the isomeric dimethoxy-1-naphthols 4a, 9a and 4b, 9b yields rotundiquinone dimethyl ether (29c) and 2,3-bijuglone dimethyl ether (29d) in the same manner.  -  Characters and spectra of the compounds are discussed.
    Notes: Mamegakinon (8a), Biramentaceon (12a), 3,3′-Bijuglon (8b) und 2,2′-Bijuglon (12b) sowie deren Methylether wurden durch Phenoloxidation geeignet substituierter 4-Methoxy-1-naphthole über indigoide Zwischenstufen vom Typ 24 synthetisiert. Die Cooxidation der isomeren Dimethoxy-1-naphthole 4a, 9a bzw. 4b, 9b lieferte analog Rotundichinon-dimethylether (29c) und 2,3-Bijuglon-dimethylether (29d).  -  Eigenschaften und Spektren der Verbindungen werden diskutiert.
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    (Cycloalkylmethyl)bis(η5-cyclopentadienyl)titan(III)-Komplexe (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1361-1370 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: (Cycloalkylmethyl)bis(η5-cyclopentadienyl)titanium(III) ComplexesReaction of bis(cyclopentadienyl)titanium dichloride (1) and isopropylmagnesium bromide (2) with the methylenecycloalkanes 3-8 (cyclopropane), 35 (cyclobutane), and 37 (cyclopentane) leads to the (cycloalkylmethyl)bis(cyclopentadienyl)titanium(III) compounds 9-14, 36, and 38. The cyclopropylmethyl complexes 12-14, which have at least two geminal methyl substituents, are stable. Compounds 9-11, 36, and 38, in which appropriate substituents are lacking, rearrange by ring opening followed by C = C bond isomerization to give the (η3-allyl)bis(η5-cyclopentadienyl)titanium complexes 23-26 and 40.
    Notes: Bei der Reaktion von Bis(cyclopentadienyl)titandichlorid (1) und Isopropylmagnesiumbromid (2) mit den Methylencycloalkanen 3-8 (Cyclopropan), 35 (Cyclobutan) und 37 (Cyclopentan) entstehen die (Cycloalkylmethyl)bis(cyclopentadienyl)titan(III)-Verbindungen 9-14, 36 und 38. Bei mindestens einer geminalen Dimethylsubstitution sind die Cyclopropylmethyl-Komplexe 12-14 stabil. Bei fehlender oder ungeeigneter Substitution lagern sich die Verbindungen 9-11, 36 und 38 durch Ringöffnung und anschließende C = C-Bindungsisomerisierung in die (η3-Allyl)bis(η5-cyclopentadienyl)titan-Komplexe 23-26 und 40 um.
    Additional Material: 2 Tab.
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    Synthesen mit α-metallierten Isocyaniden, XLIII.Versuche mit lithiierten α,ω-Alkylendiisocyaniden (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 28-36 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses with α-Metalated Isocyanides, XLIII1).  -  Experiments with Lithiated α,ω-Alkylene Diisocyanides1,2-Ethylene diisocyanide (4a) reacts with two equivalents of butyllithium (- 100°C) to give 1,1-dilithio-1,2-ethylene diisocyanide (7) which with ketones yields the oxazines 11. - 1,3-Propylene diisocyanide (4b) reacts with one equivalent butyllithium (- 70°C) to furnish 1-lithio-1,3-propylene diisocyanide (12) which cyclizes to afford 3-lithio-1-pyrrolin-3-yl isocyanide (14). With ketones, chlorotrimethylsilane, and epoxides 14 furnishes the compounds 17-19 and 21. -1,4-Butylene diisocyanide (4c) reacts (- 100°C) with one equivalent butyllithium to give 1-lithio-1,4-butylene diisocyanide (23), and with two equivalents to give 1,4-dilithio-1, 4-butylene diisocyanide (28). Both compounds are thermolabile, but can be trapped by electrophils which react below -60°C.
    Notes: 1,2-Ethylendiisocyanid (4a) reagiert mit zwei Äquivalenten Butyllithium (-100°C) zum 1,1-Dilithio-1,2-ethylendiisocyanid (7), das mit zwei Äquivalenten eines Ketons die Oxazine 11 liefert.  -  1,3-Propylendiisocyanid (4b) liefert mit einem Äquivalent Butyllithium ( - 70°C) 1-Lithio-1,3-propylendiisocyanid (12), das zum 3-Lithio-1-pyrrolin-3-ylisocyanid (14) cyclisiert, welches mit Ketonen, Chlortrimethylsilan und Epoxiden die Verbindungen 17-19 und 21 liefert.  -  1,4-Butylendiisocyanid (4c) ergibt mit einem Äquivalent Butyllithium 1-Lithio-1,4-butylendiisocyanid (23), mit zwei Åquivalenten 1,4-Dilithio-1,4-butylendiisocyanid (28) (- 100°C). Beide Lithiumverbindungen sind thermolabil, können aber mit solchen Elektrophilen abgefangen werden, die bereits unterhalb -60°C reagieren.
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    Nucleotide, XI. Synthese und Eigenschaften von Dinucleosidmonophosphaten mit Thymidin und 1-(2′-Desoxy-β-D-ribofuranosyl)lumazinen als BausteineHerrn Prof. Dr. H. Bredereck in Verehrung zum 75. Geburtstag gewidmet. (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 50-64 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Nucleotides, XI1).  -  Synthesis and Properties of Dinucleoside Monophosphates with Thymidine and 1-(2′-Deoxy-β-D-ribofuranosyl)lumazines as Building BlocksHerrn Prof. Dr. H. Bredereck in Verehrung zum 75. Geburtstag gewidmet.The synthesis of various dinucleoside monophosphates (6a-e) with thymidine (3a) and 1-(2′-deoxy-β-D-ribofuranosyl)lumazines (3b-d) as building blocks via the phosphotriester approach is described. The completely protected phosphotriesters (4a -e) as well as the partially deblocked intermediates (5a-e) have been isolated and characterized by physical methods. Intramolecular interactions in the free dinucleoside monophosphates 6a-e have been detected by the determination of the hypochromicities and measurement of CD spectra, revealing a small base-stacking effect. Enzymatic hydrolysis of the dinucleoside monophosphates with snake venom and spleen phospodiesterase strongly depends on various structural features and is greatly retarded in presence of the 6,7-diphenyllumazine moiety as an aglycone.
    Notes: Die Synthese verschiedener Dinucleosidmonophosphate (6a-e) mit Thymidin (3a) und 1-(2′-Desoxy-β-D-ribofuranosyl)lumazinen (3b-d) als Bausteine wird mit Hilfe der Phosphotriester-Methode realisiert. Die voll- (4a - e) und partiell-geschützten Phosphotriester (5a - e) werden isoliert und durch physikalische Daten charakterisiert. Intramolekulare Wechselwirkungen in den freien Dinucleosidmonophosphaten 6a-e werden durch Bestimmung der Hypochromizitäten und Aufnahme von CD-Spektren nachgewiesen und deuten auf eine schwache Basen-Stapelung hin. Enzymatische Hydrolysen dieser Dinucleosidmonophosphate mit Milz- und Schlangengift-Phosphodiesterase zeigen eine starke Strukturabhängigkeit und sind bei Gegenwart des 6,7-Diphenyllumazins als Aglykon stark verlangsamt.
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    Synthesen mit Isoxazolinen, 4. Baseninduzierte Ringöffnung von 2-Isoxazolinen; Synthese von α-Enoximen und -Enonen aus Alkenen (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 80-100 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses via Isoxazolines, 41).  -  Base-initiated Ring Opening of 2-Isoxazolines; Synthesis of α-Enoximes and -Enones from Alkenes2,3)The 2-Isoxazolines 2a - e and 5 undergo ring cleavage on treatment with lithium diisopropylamide (LDA) at -78 → 0°C to afford sterically homogeneous α-enoximes 3a-e and 6. 1H- and 13C-NMR data establish that these compounds have retained the C = N-configuration of the starting isoxazoline. Subsequent deoximation by acidic TiCl3 solution in DMF yields the α-enones 4a-e and the tetrahydropyran 7, respectively. This constitutes a new, regioselective sequence (1 → 4) for the acylation of alkenes, which avoids cationic intermediates. Studies to determine the mechanistic course and the scope of the ring cleavage reaction show that endo and/or exo anions are formed first, depending on the substitution pattern. The former may isomerize (≥ -78°C) to produce enoximates; both offer the possibility to prepare new 4- or 3α-substituted isoxazolines by the reaction with electrophiles as demonstrated by two examples (2f, 2h).
    Notes: Die 2-Isoxazoline 2a -e und 5 erleiden unter der Einwirkung von Lithiumdiisopropylamid (LDA) bei - 78 → 0°C Ringöffnung zu den sterisch einheitlichen α-Enoximen 3a - e bzw. 6. Diese weisen nach 1H- und 13C-NMR-Daten die im Edukt vorgegebene C = N-Konfiguration auf. Die anschließende Desoximierung mittels saurer TiCl3-Lösung in DMF liefert die α-Enone 4a-e bzw. das Tetrahydropyran 7. Es liegt somit eine neue regioselektive Alken-Acylierungsfolge (1 → 4) vor, die unter Vermeidung kationischer Zwischenstufen verläuft. Untersuchungen zum Mechanismus und Anwendungsbereich der Ringöffnung zeigen, daß je nach Substitutionsmuster endo-und/oder exo-Isoxazolin-Anionen 10 bzw. 11 gebildet werden. Erstere können zu Enoximaten isomerisieren (≥ -78°C); beide bieten durch Umsetzung mit Elektrophilen die Möglichkeit, neue 4- oder 3α-substituierte Isoxazoline herzustellen, was an zwei Beispielen (2f, 2h) gezeigt wird.
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    Dimere Naphthochinone, II. Einfache und regioselektive Synthese von Naphthohydrochinon-monoalkylethern über 2,3-Dihydronaphthochinone (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 140-157 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Dimeric Naphthoquinones, II1) - Simple and Regioselective Synthesis of Naphthoquinol Monoalkyl Ethers via 2,3-DihydronaphthoquinonesOn catalysis of hydrogen chloride or thionyl chloride, 1,4-naphthalenediole (2 a) reacts with primary or secundary alcohols via the tautomeric 2,3-dihydronaphthoquinone (9) to give naphthoquinol monoalkyl ethers 2b - n in high yields. The influence of the substitution pattern on the regioselectivity of the reaction has been investigated.
    Notes: Naphthohydrochinon (2a) reagiert unter Katalyse von Chlorwasserstoff oder Thionylchlorid über das tautomere 2,3-Dihydronaphthochinon (9) mit primären und sekundären Alkoholen in hoher Ausbeute zu den Naphthohydrochinon-monoalkylethern 2b-n. Der Einfluß von Substituenten auf die Regioselektivität der Reaktion wird untersucht.
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    Synthesen mit Isoxazolinen, 6. Asymmetrische Induktion bei der Reduktion von 2-Isoxazolinen zu γ-Aminoalkoholen mit zwei und drei benachbarten Stereozentren2,3) (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 122-139 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses via Isoxazolines, 61). - Asymmetric Induction in the Reduction of 2-Isoxazolines to Yield γ-Amino Alcohols with Two or Three Vicinal Stereocentres2,3)The substituted 3-aminopropanols 3 and 5 with two or three adjacent chiral centres are prepared from alkenes and nitrile oxides via LiAlH4 reduction of intermediate isoxazolines 2 and 4, respectively, in a regio- and stereoselective mode. 4-Alkyl groups give rise to β-3 in ca. 40-70% stereo-selectivity. cis-4,5-Disubstitution leads to an excess of 80 - 90% of β-5, in the case of the trans-compound 4b to an excess of 45% of β-5. 1,3-Asymmetric induction here exceeds 1,2-induction, which points to Li…O complexation during the hydride-transferring step. LiAlH4 reduction of 4,5-dimethylisoxazolines 4a and 4b shows approximate additivity of substituent effects (ΔΔG
    Notes: Die substituierten 3-Aminopropanole 3 und 5 mit zwei oder drei benachbarten Chiralitätszentren werden regio- und stereoselektiv aus Alkenen und Nitriloxiden durch LiAlH4-Reduktion der Isoxazolin-Zwischenprodukte 2 bzw. 4 erhalten. 4-Alkylgruppen bewirken bei der Reduktion zu β-3 ca. 40- bis 70proz. Stereoselektivität, bei cis-4,5-Disubstitution wird ein überschuß von 80-90%, bei trans-Stellung (4b) ein solcher von ca. 45% an β-5 erhalten. Die 1,3-asymmetrische Induktion übertrifft dabei die 1,2-Induktion, was mit Li…O-Komplexierung beim Hydrid-Additionsschritt gedeutet wird. Bei der LiAlH4-Reduktion der 4,5-Dimethylisoxazoline 4a und 4b wird näherungsweise Additivität der Substituenteneffekte (ΔΔG
    Additional Material: 2 Tab.
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    Beiträge zur Kenntnis des chromophoren Systems der Corrine, VI. Notiz über die partielle ozonolytische Ringöffnung am Dicyano-10-bromcobinamid (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 165-167 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Knowledge of the Corrin Chromophore, VIi).  -  Note on the Partial Ozonolytic Ring Cleavage of Dicyano-10-bromocobinamideReaction of dicyano-10-bromocobinamide (1) with 1.2 equivalents of ozone at - 60°C in methanol followed by reductive work-up yields the 5,6-monoseco derivative 2.
    Notes: Die Umsetzung von Dicbano-10-bromcobinamid (1) mit 1.2 Åquivalenten Ozon bei -60°C in Methanol führt nach reduktiver Aufarbeitung zum 5,6-Monoseco-Derivat 2.
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    Notiz über positionsspezifische übergangsmetallbedingte Hydridabstraktion aus Carbanionen (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 171-173 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Hydride Eliminations, VIII1).  -  Note on Site-Specific Hydride Abstraction from CarbanionsReaction of lithium and magnesium alkyl compounds at - 20 to 0°C with ethylene in the presence of nickel chloride leads under β-hydride abstraction to completely site-specific olefin formation. In stereochemically relevant cases the formation of the thermodynamically less stable Hofmann product is slightly preferred.
    Notes: Lithium- und Magnesiumalkylverbindungen reagieren bei - 20 bis 0°C mit Ethylen in Gegenwart von Nickelchlorid unter β-Hydridabstraktion in streng positionsspezifischer Bildung zu Olefinen. In stereochemisch relevanten Füllen wird die Bildung des thermodynamisch weniger stabilen Hofmann-Produkts geringfügig bevorzugt.
    Additional Material: 1 Tab.
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    Beiträge zur Kenntnis des chromophoren Systems der Corrine, VII. Notiz über die Reaktion von Diazoessigsäure-methylester mit Lactamen; eine Modellreaktion zur Cyclisierung von 5,6-Dioxo-monosecocorrinenKorrespondenz bitte an H. H. Inhoffen, Institut für Organische Chemie der Techn. Univ., Schleinitzstraße, D-3300 Braunschweig, richten. (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 168-170 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Knowledge of the Corrin Chromophore, VII1).  -  Note on the Reaction of Methyl Diazoacetate with Lactams; a Model Reaction for the Cyclisation of 5,6-DioxomonosecocorrinsThe copper-catalyzed reaction of methyl diazoacetate with the lactam 1 or the thiolactams 3 and 4 yields the O and S-alkylated products. In the case of lactam 2 the N-alkyl compound 10 is obtained.
    Notes: Die Umsetzung von Diazoessigsäure-methylester mit dem Lactam 1 oder den Thiolactamen 3 und 4 führt unter Kupferkatalyse zu O- bzw. S-alkylierten Produkten, im Falle des Lactams 2 zur N-Alkylverbindung 10.
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    Synthese natürlich vorkommender p-Hydroxyacetophenon-Derivate, IIIHerrn Prof. Dr. M. Seefelder zum 60. Geburtstag gewidmet. (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 185-191 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of Naturally Occurring p-Hydroxyacetophenone Derivatives, III Synthese natürlich vorkommender p-Hydroxyacetophenon-Derivate, IIIHerrn Prof. Dr. M. Seefelder zum 60. Geburtstag gewidmet.Starting with different p-hydroxyacetophenone derivatives ten naturally occurring compounds have been synthesized. The synthesis of the vinyl chromene 18 gave unexpected difficulties as the dehydration of the corresponding alcohol was not successful. However, the tosylhydrazone 17 afforded the desired vinyl compound.
    Notes: Ausgehend von p-Hydrogxyacetophenon-Derivaten wurden zehn natürlich vorkommende Verbindungen dargestellt. Die Synthese des Vinylchromens 18 machte unerwartete Schwierigkeiten, da die Wasserabspaltung bei dem entsprechenden Alkohol nicht gelang. Jedoch liefert das Tosylhydrazon 17 die gewünschte Vinylverbindung.
    Type of Medium: Electronic Resource
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    Studien zur β-Lactam-Synthese, VI. Austausch der Tritylthio- und der Methylthio-Gruppe in N-geschützten 2-(trans-4-Alkylthio-3-amino-2-oxo-1-azetidinyl)-acrylsäure-alkylestern2) (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1527-1539 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Studies on β-Lactam Synthesis, VI.  -  Exchange of Tritylthio and Methylthio Groups in N-Protected Alkyl 2-(trans-4-Alkylthio-3-amino-2-oxo-1-azetidinyl)acrylatesReaction of trans-3-azido- and trans-3-phthalimido-4-tritylthio-2-azetidinones 5a and 5b with silver nitrate in methanol according to the method of Lattrell yielded the silver thiolates 6a and 6b, respectively, whereas the trans-4-acylamino derivative 9a was solvolyzed to give trans-4-methyl ether 10a [presumably via oxazolineazetidinone (azetooxazolone) 30a].  -  Oxidative detritylation of 11 with iodine provided the azetidinone-4-disulfide 14. A one pot reaction of iodine/sodium p-toluenesulfinate with trityl thioethers 11 and 9a afforded the trans-4-(p-toluenesulfonylthio)-2-azetidinones 13 and 18.  -  Cleavage of methyl thioethers 20 and 27 by sulfuryl chloride and of sulfoxides 21 and 28 by thionyl chloride yielded predominantly trans-chlorides 23 and 29. The trans-3-acylamino-4-chloro-2-azetidinones 29 were cyclized to give cis-fused 4-oxa-2,6-diazabicyclo[3.2.0]hept-2-en-7-ones (azeto[3,2-d]oxazolones) 30, which react with methanol (catalyzed by tin(II) chloride) to yield trans-3-acylamino-4-methoxy-2-azetidinones 10.
    Notes: Die trans-3-Azido- und trans-3-Phthalimido-4-tritylthio-2-azetidinone 5a und 5b ergaben nach der Methode von Lattrell mit Silbernitrat in Methanol die Silberthiolate 6a und 6b, während das trans-3-Acylamino-Derivat 9a [vermutlich über das Oxazolinazetidinon (Acetooxazolon) 30a] zum trans-4-Methylether 10a solvolysierte.  -  Die oxidative Detritylierung von 11 mit Iod führte zum Azetidinon-4-disulfid 14. Mit Iod/Natrium-p-toluolsulfinat erhielt man aus den Tritylthioethern 11 und 9a im “Eintopf”-Verfahren die trans-4-(p-Toluolsulfonylthio)-2-azetidinone 13 und 18.  -  Die Spaltung der Methylthioether 20 und 27 mit Sulfurylchlorid oder der Sulfoxide 21 und 28 mit Thionylchlorid ergab überwiegend die trans-Chloride 23 bzw. 29. Die trans-3-Acyl-amino-4-chlor-2-azetidinone 29 wurden zu den cis-verknüpften 4-Oxa-2,6-diazabicyclo[3.2.0]-hept-2-en-7-onen (Azeto[3,2-d]oxazolonen) 30 cyclisiert und mit Methanol unter Zinn(II)-chlorid-Katalyse zu den trans-4-Methoxy-2-azetidinonen 10 geöffnet.
    Additional Material: 1 Tab.
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    Über Cyanoelpasolithe AI2BIMIII(CN)6 mit AI = Tetramethyl-ammonium und das Fluorid [N(CH3)4]2CsFeF6Professor Karl Dimroth zum 70. Geburtstage am 18. August 1980 gewidmet. (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1549-1556 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cyano Elpasolites AI2BIMIII(CN)6 with AI = Tetramethylammonium and the Fluoride [N(CH3)4]2CsFeF6Professor Karl Dimroth zum 70. Geburtstage am 18. August 1980 gewidmet.The cubic compounds [N(CH3)4]2CsM(CN)6 (MIII = Cr, Fe, Co) and the tetragonal product of fluorination, [N(CH3)4]2CsFeF6, are characterized by their X-ray powder and IR-spectroscopic data.
    Notes: Die kubischen Verbindungen [N(CH3)4]2CsM(CN)6 (MIII = Cr, Fe, Co) und das tetragonale Fluorierungsprodukt [N(CH3)4]2CsFeF6 werden röntgenographisch und IR-spektroskopisch charakterisiert.
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    Siebengliedrige Ringe durch 1,5-Cycloadditionen, VI. 7-Aminoperhydro-1,4-oxazepine und -diazepine (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1573-1582 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Seven-Membered Rings by 1,5-Cycloadditions, VI1). - 7-Aminoperhydro-1,4-oxazepines and -diazepines3-Alkyl-1,3-oxazolidines 2 react with enamines 1 in the presence of trifluoroacetic acid to give 7-dialkylaminoperhydro-1,4-oxazepines 3. 1,3-Dimethyl-1,3-imidazolidine (2d) reacts with 4-(2-methyl-1-propenyl)morpholine (1a) to give 1,4,6,6-tetramethyl-7-morpholino-2,3,4,5,6,7-hexa-hydro-1 H-1,4-diazepine (3m)
    Notes: 3-Alkyl-1,3-oxazolidine 2 geben mit den Enaminen 1 in Gegenwart von Trifluoressigsäure die 7-Dialkylaminoperhydro-1,4-oxazepine 3. 1,3-Dimethyl-1,3-imidazolidin (2d) reagiert mit 4-(2-Methyl-1-propenyl)morpholin (1a) zum 1,4,6,6-Tetramethyl-7-morpholino-2,3,4,5,6,7-hexahydro-1 H-1,4-diazepin (3m).
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    3H-Selenolo[2,3-d]-1,2-thiol-3-on und 8H-Diselenolo-[3,2-b:2′,3′-e]thiopyran-8-on, zwei neue Ringsysteme (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1620-1622 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 3H-Selenolo[2,3-d]-1,2-thiol-3-one and 8H-Diselenolo[3,2-b: 2′,3′-e]thiopyran-8-one, Two New Ring SystemsThe two title compounds 1 and 3a are described. They each contain a new heterocyclic ring system. The thiopyran 3a is obtained by refluxing 1 with copper powder in xylene.
    Notes: Die Titelverbindungen 1 und 3a werden beschrieben. Sie enthalten beide ein bisher unbekanntes heterocyclisches Ringsystem. Das Thiopyran 3a entsteht durch Kochen von 1 mit Kupferpulver in Xylol.
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    Notiz zur Reaktion von Oxepin mit Nitrosoverbindungen (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1630-1631 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Note on the Reaction of Oxepin with Nitroso CompoundsOxepin (2) and p-chloronitrosobenzene (1) react to give the nitrone 3.
    Notes: Oxepin (2) gibt mit p-Chlornitrosobenzol (1) das Nitron 3.
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    Masthead (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980) 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198019801101
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    Synthese und NMR-Spektren von Diazadiphosphetidinen, II (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1651-1658 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and NMR Spectra of Diazadiphosphetidines, II1,3,2λ5,4λ5-Diazadiphosphetidines are synthesized from PCl5 and aniline derivatives. They are partially or fully dissociated in solution to give substituted (phenylimido)phosphoric trichlorides. The dependence of the dissociation on the solvent, the temperature, and the concentration has been investigated. The reaction products of anilines and C6H5PCl4 or (C6H5)2PCl3 are exclusively monomers, i. e. they are substituted phenyl(phenylimido)phosphonic dichlorides 3 or diphenyl-(phenylimido)phosphinic chlorides 4, respectively.
    Notes: 1,3,2λ5,4λ5-Diazadiphosphetidine 1 werden aus PCl5 und Anilinderivaten synthetisiert. Sie liegen in Lösung teilweise oder ganz dissoziiert als substituierte (Phenylimido)phosphorsäuretrichloride 2 vor. Es wurde die Abhängigkeit der Dissoziation vom Lösungsmittel, der Temperatur und der Konzentration untersucht. Die Reaktionsprodukte aus Anilinen und C6H5PCl4 oder (C6H5)2PCl3 sind ausschließlich monomer, d. h. es handelt sich um substituierte Phenyl(phenylimido)phosphonsäuredichloride 3 bzw. Diphenyl(phenylimido)phosphinsäurechloride 4.
    Additional Material: 5 Tab.
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    Reaktionen von Chlorboranen mit bifunktionellen Basen (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1659-1664 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Chloroboranes with Bifunctional BasesReaction of trichloroborane with 2-(trimethylsilylamino)pyridine (1b) and 2-(trimethylsilyloxy)-pyridine (2b) yields the dimeric dichloro(2-pyridylamino)borane 4 and the dimeric dichloro-(2-pyridyloxy)borane 5, respectively. In a 1:2 molar ratio tetrachlorodiborane(4) and 2b react to form the bicyclus 6, while equimolar amounts react in a complex way.
    Notes: Aus Trichlorboran erhält man mit 2-(Trimethylsilylamino)pyridin (1b) und 2-(Trimethylsilyloxy)-pyridin (2b) das dimere Dichlor(2-pyridylamino)boran 4 bzw. das dimere Dichlor(2-pyridyloxy)-boran 5. Tetrachlordiboran(4) und 2b setzen sich bei einem Molverhältnis von 1:2 zum Bicyclus 6 um, während äquimolare Mengen unübersichtlich reagieren.
    Type of Medium: Electronic Resource
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    Nucleophile Substitution an Tricyclo[4.4.1.01,6]undec-3-en-11-diazonium-Ionen (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1689-1698 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Nucleophilic Substitution at Tricyclo[4.4.1.01,6]undec-3-ene-11-diazonium IonsThe nitrous acid deamination of tricyclo[4.4.1.01,6]undec-3-en-11-ylamines 14 and 16 in the presence of sodium bromide afforded the tricyclic bromides 18 and 19 with 〉 99% retention. Configurations were assigned by chemical correlation via the carboxylic acids 13 and 15. Deuterium incorporation in D2O indicated some epimerization of the diazonium ions at higher concentrations of sodium bromide, leading to a decrease in stereospecificity. The retention of configuration observed in this study is attributed to the intervention of partially opened cyclopropyl cations.
    Notes: Die Desaminierung der Tricyclo[4.4.1.01,6]undec-3-en-11-ylamine 14 und 16 mit salpetriger Säure in Gegenwart von Natriumbromid ergab die tricyclischen Bromide 18 und 19 mit 〉 99% Konfigurationserhaltung. Die Konfigurationszuordnung erfolgte durch chemische Korrelation über die Carbonsäuren 13 und 15. Deuterium-Einbau in D2O zeigte eine geringe Epimerisierung der Diazonium-Ionen bei höheren Natriumbromid-Konzentrationen an, die zu verminderter Stereospezifität führt. Die beobachtete Konfigurationserhaltung wird mit dem Auftreten teilgeöffneter Cyclopropylkationen erklärt.
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    Zur Struktur rhodiumhaltiger Corrinoide (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1699-1710 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Structure of Rhodium Containing CorrinoidsReaction of hydrogenobyrinic acid a,c-diamide (1) with [Rh(CO)2Cl]2 in glacial acetic acid/ethanol (1:1; vol.: vol.) yields rhodibyrinic acid a,c-diamide 2 as the main product. The structure of 2 is confirmed by X-ray analysis. Esterification of 2 with methanol/sulfuric acid leads to rhodibyrinic acid pentamethyl ester a,c-diamide 3a and to small amounts of its 8- and 13-epimers. Their configurations are established by CD, 1H- and 13C-NMR spectroscopy.
    Notes: Durch Umsetzung von Hydrogenobyrinsäure-a,c-diamid (1) mit [Rh(CO)2Cl]2 in Eisessig/Ethanol (1:1; Vol.: Vol.) erhält man als Hauptprodukt Rhodibyrinsäure-a,c-diamid 2. Die Identität von 2 wird durch Röntgenstrukturanalyse bestätigt. Veresterung von 2 mit Methanol/Schwefelsäure führt neben Rhodibyrinsäure-pentamethylester-a,c-diamid 3a zu den entsprechenden 8- und 13-Epimeren. Deren Konfiguration wird durch CD, 1H- und 13C-NMR-Spektroskopie gesichert.
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    Reaktionsfähigkeit von Trimethylsilylierungsreagentien (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1718-1721 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactivity of Trimethylsilylation ReagentsThe reactivity of various trimethylsilylation reagents 1 on cyclopentanone (2a) and diisopropyl ketone (2b) has been investigated. Silylation potentials of the reagents 1 are reported.
    Notes: Es wird die Reaktionsfähigkeit einiger Trimethylsilylierungsreagentien 1 gegenüber Cyclopentanon (2a) und Diisopropylketon (2b) untersucht. Silylierungspotentiale der Reagentien 1 werden angegeben.
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    Konfiguration von 2-Amino-4-hydroxy-4-(5-hydroxy-2-pyridyl)-3-methylbuttersäure, der N-terminalen Aminosäure der Nikkomycine (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1728-1735 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Configuration of 2-Amino-4-hydroxy-4-(5-hydroxy-2-pyridyl)-3-methylbutyric Acid, the N-Terminal Amino Acid of the NikkomycinsThe N-ethylthio(thiocarbonyl)derivative 2 of the N-terminal amino acid 1 of the nikkomycin antibiotics shows a positive Cotton effect in its circular dichroism spectrum and therefore 1 is assigned to the L-series. The relative configuration of the C atoms 3 and 4 was ascertained by 1H-NMR investigations and crystal structure analysis. Accordingly, 1 is assigned the configuration 2S,3S,4S.
    Notes: Das N-Ethylthio(thiocarbonyl)derivat 2 der N-terminalen Aminosäure 1 der Nikkomycin-Antibiotika weist Circulardichroismus mit positivem Cottoneffekt auf und 1 ist daher der L-Reihe zu-zuordnen. Die relative Konfiguration an den C-Atomen 3 und 4 wurde durch 1H-NMR- und Kristallstrukturuntersuchungen bestimmt. Danach hat 1 die Konfiguration 2S,3S,4S.
    Additional Material: 3 Ill.
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    Eine neue Synthese von 3-Benzoylmethylen-2,3-dihydrofuranen1) (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1744-1750 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A New Synthesis of 3-Benzoylmethylene-2,3-dihydrofuransThe unknown 3-benzoylmethylene-2,3-dihydrofurans 2 has been synthesized by isomerization of ditertiary diacetylenediols 1 in the presence of mercury salts. Sometimes carbocyanine type dyes 5 are formed as by-products.
    Notes: Die bisher unbekannten 3-Benzoylmethylen-2,3-dihydrofurane 2 wurden durch Isomerisierung von ditertiären Diacetylendiolen 1 in Gegenwart von Quecksilbersalzen erhalten. Als Nebenprodukte können gelegentlich Verbindungen vom Typ der Cyaninfarbstoffe 5 gebildet werden.
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    URL: http://dx.doi.org/10.1002/jlac.198019801114
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    Metallierte Stickstoffderivate der Kohlensäure, in der organischen Synthese, XV. 2-Azaallylanionen aus N-(Benzyl)imidodithiokohlensäure-, N-(Benzyl)imidomonothiokohlensäure- und N-(Benzyl)imidokohlensäure-dialkylestern als Benzylaminanion-Äquivalente (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1751-1764 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Metalated Nitrogen Derivatives of Carbonic Acid in Organic Synthesis, XV. - 2-Azaallyl Anions from Dialkyl N-(Benzyl)imidodithiocarbonates, -monothiocarbonates, and -carbonates as α-Benzylamine Anion Equivalents2,3)S,S′-Dimethyl N-(benzyl)imidodithiocarbonate (4a) was deprotonated by means of potassium tert-butoxide in THF or butyllithium in THF/HMPTA/hexane to give the 2-azaallyl anion 7a Its alkylation yields mixtures of the α- and γ-substitution products 11a and 14a. In contrast, anion 7b, obtained from the S.S′-diethyl derivative 4b, is trapped by electrophiles predominantly in α-position, yielding 11b with high regioselectivity. Thus 4b constitutes a synthetic equivalent for α-metalated benzylamine 1. The less acidic O,O′- and O,S-dialkyl derivatives 5 or 6 were also deprotonated and alkylated to give only α-adducts 12 or 13 via anions 8 or 9. - Lithium diisopropylamide under kinetic control predominantly abstracts a proton from an S-methyl group of 4a. The intermediate lithium compound 21 was trapped as silane 23 (besides 14aa). - Some further deprotonation experiments were also performed with the imino compounds 11aa, 11ab, 32a, and 32b in order to explore the scope of the metalation reaction.
    Notes: N-(Benzyl)imidodithiokohlensäure-S,S′-dimethylester (4a) wurde mit Kalium-tert-butoxid (in THF) oder mit Butyllithium (in THF/HMPTA/Hexan) zum 2-Azaallylanion 7a deprotoniert. Die Alkylierung von 7a ergibt Mischungen der α- und γ-Substitutionsprodukte 11a und 14a. Das Anion 7b (erhalten aus dem S,S′-Diethylester 4b) hingegen wird durch Elektrophile mit hoher Regioselektivität in α-Stellung zu lib substituiert und ist daher als Syntheseäquivalent für ein α-Benzylaminanion 1 nutzbar. Die schwächer aciden O,O′- und O,S-Dialkylderivate 5 und 6 ließen sich ebenfalls zu 2-Azaallylanionen 8 und 9 deprotonieren. Sie werden ausschließlich zu 12 und 13 alkyliert und silyliert. - Lithiumdiisopropylamid abstrahiert in 4a unter kinetischer Kontrolle bevorzugt ein Proton aus den S-Methylgruppen; das intermediäre Lithiumchelat 21 wurde als Silan 23 (im Gemisch mit 14aa) abgefangen. - Einige weitere Metallierungsexperimente wurden mit den Iminen 11aa, 11ab, 32a und 32b ausgeführt, um die Anwendungsbreite der Reaktion abzugrenzen.
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    Ligandstruktur und Komplexierung, LI. Vielzähnige Neutralliganden mit variablen Hohlräumen und Pseudohohlräumen (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 425-440 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Ligand Structure and Complexation, LI1).  -  Multidentate Neutral Ligands with Variable Cavities and Pseudo CavitiesNew cyclic and non-cyclic neutral ligand systems have been synthesized. They contain repeating oligoethylene glycol ethers and carboxamide functions, which allow attractive interactions between single chain segments and with terminal groups. Crystalline complexes with alkali and alkaline earth metal ions have been isolated. The complexation of Na⊕ and competing cations has been studied with the aid of 23Na-NMR spectroscopy: The sodium cation can also be displaced by neutral molecules such as urea. Chiral open-chain ligands and their complexation with alkali and alkaline earth metal salts are described.
    Notes: Neue cyclische und offenkettige Neutralligandsysteme wurden dargestellt. Sie enthalten sich wiederholende Oligoethylenglykolether- und Carbonsäureamidfunktionen, die anziehende Wechselwirkungen einzelner Kettensegmente und zwischen endständigen Gruppen gestatten. Kristalline Komplexe mit Alkali- und Erdalkalimetallionen wurden dargestellt. Mit Hilfe der 23Na-NMR-Spektroskopie wurde die Komplexierung mit Na⊕ und konkurrierenden Ionen studiert: Das Natriumkation kann auch durch Neutralmoleküle wie Harnstoff verdrängt werden. Chirale offenkettige Liganden und ihre Komplexierung mit Alkali- und Erdalkalimetallsalzen werden beschrieben.
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    Reactionen mesoionischer Fünfringheterocyclen mit O-chinoiden Verbindungen, II. Ein Beitrag zum Problem der Ketentautomerie bei mesoionischen 1,3-Oxazolium-5-olaten (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1836-1849 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Mesoionic Five-membered Heterocycles with o-Quinonoid Compounds, II1).  -  A Contribution to the Problem of Ketene Tautomers of 1,3-Oxazolium-5-olates1,3-Oxazolium-5-olates acylated at C-4 react with tetrachloro-o-benzoquinone (9) to give 2,3-dihydro-1,4-benzodioxin-2-ones 10 which can formally be derived from the valence tautomeric ketenes 2. There is evidence for the assumption that ketenes are not involved in these reactions as intermediates. Furthermore, the products 15a, b which probably result from [4 + 4] cycloadducts formed primarily, have been isolated. Oxazolo[3,2-a]pyridinium-2-olates 8 acylated at C-3 react with 9 to give 1:2 adducts 20.
    Notes: C-4-acylierte 1,3-Oxazolium-5-olate reagieren mit Tetrachlor-o-benzochinon (9) unter Bildung von 2,3-Dihydro-1,4-benzodioxin-2-onen 10, die sich formal von den valenztautomeren Ketenen 2 ableiten. Es wird ein Hinweis darauf erhalten, daß Ketene bei diesen Umsetzungen nicht ais Zwischenprodukte auftreten. Weiterhin werden die Produkte 15a, b isoliert, die möglicherweise aus primär gebildeten [4 + 4]-Cycloaddukten entstehen. C-3-acylierte Oxazolo[3,2-a]pyridinium-2-olate 8 liefern mit 9 die 1:2-Addukte 20.
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    Cyclisierungen zu 9,11-disubstituierten Acronycin-DerivatenHerrn Prof. Dr. M. Seefelder zum 60. Geburtstag gewidmet. (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 503-511 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cyclizations to 9,11-Substituted Acronycine DerivativesHerrn Prof. Dr. M. Seefelder zum 60. Geburtstag gewidmet.The following methods for the cyclization of olefinic precursors of acronycine, which give rise to derivatives of this alkaloid 4a substituted in positions 9 and 11, are reported: Lewis acid catalysed olefin aldehyde cyclization and subsequent oxidation converts 1b into 11-hydroxynoracronycine 4e, while 1f and 7a give 9-bromonoracronycine 4c. Base catalyzed cyclization of the oxoester 2 affords the 9,11-dihydroxy derivative 10, while the corresponding oxoaldehyde, obtainable by reduction of the enol lactone 3, gives the 9-hydroxyacridone 12.
    Notes: Es wird über folgende Methoden der Cyclisierung olefinischer Acronycinvorstufen zu 9- und 11-substituierten Derivaten dieses Alkaloids1) 4a berichtet: Lewissäuren-katalysierte Olefin-Aldehyd-Cylisierung führt, ausgehend von 1b, nach Oxidation zu 11-Hydroxynoracronycin 4e; aus 1f und 7a wird 9-Bromnoracronycin 4c erhalten. Basenkatalysierte Cylisierung des Oxoesters 2 ergibt das 9,11-Dihydroxyderivat 10, der durch Readuktion des Enollactons 3 gewinnbare kor-respondierende Oxoaldehyd das 9-Hydroxyacridon 12.
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    Desaminierung von β- und γ-Aminoalkoholen (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 518-532 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Deamination of β- and γ-Amino AlcoholsNitrous acid deaminations of the β-amino alcohols 2 and 12 afford 1,2-diols as well as ketones by pinacolic rearrangement. Both types of products arise with predominant inversion of configuration. Stereochemical studies and isotopic labeling reveal that formation of the diols involves an oxygen shift, presumably via oxirane intermediates. Deamination of the γ-amino alcohol 37 induces, in part, sequential rearrangements to give products also obtained from 12, but in different proportions and enantiomeric purities. Conformational control provides a reasonable explanation of our results.
    Notes: Die Desaminierung der β-Aminoalkohole 2 und 12 mit salpetriger Säure ergibt 1,2-Diole und durch Pinakolumlagerung Ketone. Beide Produkte werden mit überwiegender Konfigurationsumkehrung gebildet. Stereochemische Untersuchungen und Isotopenmarkierungen zeigen, daß die 1,2-Diole unter Sauerstoffverschiebung entstehen, wahrscheinlich über Oxiran-Zwischen-stufen. Desaminierung des γ-Aminoalkohols 37 führt zum Teil zu Mehrfachumlagerungen, aus denen die gleichen Produkte wie aus 12 hervorgehen, jedoch in unterschiedlicher Menge und enantiomerer Reinheit. Unsere Ergebnisse lassen sich durch konformative Kontrolle plausibel deuten.
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    Anellierungsreaktionen von N-Heterocyclen zu kondensierten Pyridonen mit Stickstoffbrückenatom (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 542-556 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Annelation Reactions of N-Heterocycles to Condensed Pyridones with Bridgehead NitrogenThe Horner-Wittig reaction of aromatic and heteroaromatic aldehydes with phosphono succinates gives the methylenesuccinates 2a - m and 4a - k in satisfactory yields. The compounds obtained have the E-configuration, as shown by 1H-NMR-spectroscopic and by chemical investigations. When heterocyclic aldehydes 3a - m having a formyl function in the α-position to a nitrogen atom are used in this reaction, pyridones 5a - m with bridgehead nitrogen can be obtained directly or via the methylene succinates.
    Notes: Die Horner-Wittig-Reaktion von aromatischen und heteroaromatischen Aldehyden mit Phosphonobernsteinsäureestern führt zu den Methylenbernsteinsäureestern 2a - m und 4a - k in befriedigenden Ausbeuten. Wie durch 1H-NMR-spektroskopische und chemische Untersuchungen gezeigt wird, haben diese Verbindungen E-Konfiguration. Setzt man die heterocyclischen Aldehyde 3a - m mit Formylgruppe in α-Stellung zu einem Stickstoffatom um, so können  -  direkt oder über die Methylenbernsteinsäureester  -  die kondensierten Pyridone 5a - m erhalten werden.
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    Biphenyl(tricarbonylchrom)-Komplexe, V. Optisch aktive Tricarbonylchrom-Komplexe der Diphensäure und ihrer Derivate  -  Enantiomerenreinheit, Circulardichroismus und absolute Konfiguration (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1877-1888 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stereochemistry of Metallocenes, XLVI1).  -  Biphenyl(tricarbonylchromium) Complexes, V1).  -  Optically Active Tricarbonylchromium Complexes of Diphenic Acid and its Derivatives  -  Enantiomeric Purity, Circular Dichroism and Absolute ConfigurationOptically active mono and bis(tricarbonylchromium) complexes of diphenic acid and its monomethyl ester (cf. 7 and 8) were prepared by resolution via their cinchonidinium salts with enantiomeric purities up to 8%. Kinetic resolution of the corresponding aldehyde 12 via reduction with a chiral lithium aluminium hydride was more successful. In this case either ( + )-12 and the alcohol (-)-10 or the lactone (-)-16 were obtained. The maximum rotations [α]20D (in acetone) were determined by application of a chiral shift reagent to (-)-10 being 516°, 832° and 1094° for 10, 12 and 16; the optical yield of the asymmetric reduction was 33%. Because of the preferred configurations and conformations of the biscomplexes and after comparing the CD spectra with those of benchrotrenes of known absolute configuration the chirality (5)M-(R)A-(S)M is proposed for (-)-10 and related biphenyl complexes (-)-12 and (-)-16.
    Notes: Optisch aktive Mono- und Bis(tricarbonylchrom)-Komplexe der Diphensäure und ihres Monomethylesters (vergleiche 7 und 8) wurden durch Racematspaltung über die Cinchonidiniumsalze mit enantiomeren Reinheiten bis zu 8% erhalten. Bessere Ergebnisse lieferte die kinetische Racematspaltung durch Reduktion des entsprechenden Aldehyds 12 mit einem chiralen Lithiumaluminiumhydrid, wobei entweder ( + )-12 und der Alkohol (-)-10 oder das Lacton (-)-16 entstanden. Die maximalen [α]20D-Werte (in Aceton) wurden durch Anwendung eines chiralen Verschiebungsreagenzes auf (-)-10 ermittelt. Sie betragen für 10, 12 und 16 516°, 832° und 1094°. Für die optische Ausbeute der asymmetrischen Reduktion wurde 33% ermittelt. Aufgrund der bevorzugten Konfiguration und Konformation der Bis-Komplexe wird nach Vergleich der CD-Spektren mit jenen von Benchrotrenen bekannter Absolutkonfiguration für (-)-10 und die damit korrelierten Biphenylkomplexe (-)-12 und (-)-16 die Chiralität (5)M-(R)A-(S)M vorgeschlagen.
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    Notiz über das ungewöhnliche Verhalten von 2,3,4,5-Tetrahydro-1,5-benzothiazepin-4-onen bei der Arylierung (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1913-1916 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Note on Unusual Behaviour of 2,3,4,5-Tetrahydro-1,5-benzothiazepin-4-ones During ArylationThe 5-aryl-2,3,4,5-tetrahydro-1,5-benzothiazepines 3a-c habe been synthesized by arylation of the corresponding 2,3,4,5-tetrahydro-1,5-benzothiazepin-4-ones 1. However, in some of these reactions the diaryl sulfides 4a, b and 5 were formed.
    Notes: Die 5-Aryl-2,3,4,5-tetrahydro-1,5-benzothiazepin-4-one 3a-c wurden durch Arylierung der entsprechenden 2,3,4,5-Tetrahydro-1,5-benzothiazepin-4-one 1 hergestellt. Bei einigen dieser Umsetzungen wurden jedoch die Diarylsulfide 4a, b und 5 erhalten.
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    Umsetzungen α-metallierter Isocyanide mit einigen 1,3-Dipolen (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 600-610 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses with α-Metalated Isocyanides, XLV1).  -  Reactions of α-Metalated Isocyanides with Some 1,3-DipolesReaction of α-metalated isocyanides 1a - c, f with alkylideneamine oxides (nitrones) 4 affords the 2-imidazolidinones 8. The 6-metalated 2,3-dihydro-4-H-1,2,5-oxadiazine of type 5 is postulated as decisive intermediate.  -  Benzonitrile oxide (17) reacts analogously with 1a and 1b to give 4-imidazolin-2-ones 18 and with 1e to give the 3-imidazolin-2-one 19.  -  Phenyl azide (20) reacts with two moles of 1b to give 5-(benzylideneamino)-4H,5H-1,2,3-triazoline 24. The reaction course is discussed.
    Notes: Die α-metallierten Isocyanide 1a - c, f reagieren mit den Alkylidenaminoxiden (Nitronen) 4 zu 2-Imidazolidinonen des Typs 8. Als entscheidende Zwischenstufe wird ein 6-metalliertes 2,3-Dihydro-4H-1,2,5-oxadiazin vom Typ 5 postuliert.  -  Benzonitriloxid (17) ergibt mit 1a und 1b analog die 4-Imidazolin-2-one 18, mit 1e das 3-Imidazolin-2-on 19.  -  Phenylazid (20) setzt sich mit zwei Äquivalenten 1b zum 5-Benzylidenamino-4H,5H-1,2,3-triazolin 24 um. Der Reaktions-verlauf wird diskutiert.
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    Zur Chemie der Schwefeldiimide, 8. En-Reaktionen mit Schwefeldiimiden  -  Struktur der En-Komponente und Reaktivität bei der Umsetzung mit Ditosylschwefeldiimid (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 629-649 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Chemistry of Sulfur Diimides, 81).  -  Ene Reactions with Sulfur Diimides  -  Structure of the Ene Components and Reactivity in the Reaction with Ditosyl Sulfur DiimideN,N)′-Ditosyl sulfur diimide (1) is an exceptionally reactive enophilic compound. Its reactions with many allylic derivatives give sulfinamidines 3 or  -  by sigmatropic rearrangements of 3  -  diamino sulfane derivatives 4, respectively, in good yields. Conclusions concerning relative reactivities of the ene compounds and the regio- and stereoselectivity of the reaction sequence are drawn from the results of the NMR spectrometric investigation of the reactions.
    Notes: N,N)′-Ditosylschwefeldiimid (1) ist ein außerordentlich reaktives Enophil, dessen Umsetzung mit einer großen Anzahl von Propenderivaten 2 in guter Ausbeute die Sulfinamidine 3 oder durch deren sigmatrope Umlagerung die Diaminosulfanderivate 4 liefert. Die 1H-NMR-spektrometrischen Untersuchungen dieser Umsetzungen erlauben Aussagen über die relativen Reaktivitäten der En-Komponenten und die Regio- und Stereoselektivität der Reaktionsfolge.
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    Ergebnisse nichtbindender Wechselwirkungen, II. Notiz zur Umlagerung der isomeren Tetracyclo[6.2.1.13,6.02,7]dodecane (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 650-652 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Results of Nonbonded Interactions, II1).  -  Note on the Rearrangement of Isomeric Tetracyclo-[6.2.1.13,6.02,7]dodecanesThe endo-endo-chloride 1b can be rearranged to the endo-exo-chloride 2b with AlCl3 in CCl4. endo-exo-Chloride 2c is converted into 97% chloride 3b and 3% 2c.
    Notes: Das endo-endo-Chlorid 1b läßt sich mit AlCl3 in CCl4 quantitativ in 2b umlagern; das exo-endo-Chlorid 2c ergibt unter diesen Bedingungen eine Mischung von 97% Umlagerungsprodukt 3b und 3% 2c.
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  • 87
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    Pyrane, 84. Hexahydrobenzotripyrane (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 2021-2030 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Pyrans, 84.  -  HexahydrobenzotripyransCatalytic hydrogenation of the benzotripyranone 3 yields the hexahydrobenzotripyrans 5 und 6, while ring closure reactions of the 1,2,4-benzenetriyltris(3-oxypropionic acid) 16c and catalytic hydrogenation lead to the less symmetric isomers 21 und 12.
    Notes: Die Hexahydrobenzotripyrane 5 und 6 lassen sich durch katalytisches Hydrieren des Benzotripyranons 3 gewinnen, die weniger symmetrischen Isomere 21 und 12 aus der 1,2,4-Benzoltriyltris(3-oxypropionsäure) 16c durch Ringschlußreaktionen sowie katalytisches Hydrieren.
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  • 88
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    Reationen mit Phosphinalkylenen, XXXIX. Neue Aufbaumöglichkeiten für 1-Bromacetylene und aromatische sowie konjugierte EnineProf. Dr. M. Seefelder zum 60. Geburtstag. (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 2061-2071 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions with Phosphinealkylenes, XXXIX.  -  New Methods for the Preparation of 1-Bromoacetylenes and EnynesProf. Dr. M. Seefelder zum 60. Geburtstag.1,1-Dibromoolefins 4 are obtained in good yield from the reaction of aldehydes 1 with triphenyl-phosphane (2) and carbon tetrabromide (3). Reaction of 4 with three moles of methylene(triphenyl)phosphorane (8) leads to the propargylidene(triphenyl)phosphoranes 11 which react with aldehydes to give the enynes 13. The ylides 11 can also be prepared via the reaction of bromo-acetylenes 7, which can be obtained from 4, with two moles of 8. This reaction sequence allows the synthesis of new retinoids with enyne structures from retinal.
    Notes: Aus Aldehyden 1, Triphenylphosphan 2 und Tetrabrommethan 3 erhält man in guten Ausbeuten 1,1-Dibromolefine 4. Ihre Reaktion mit 3 Mol Methylen(triphenyl)phosphoran 8 führt zu den Propargyliden(triphenyl)phosphoranen 11, die sich mit Aldehyden zu den Eninen 13 umsetzen. 13 ist auch durch Reaktion der aus 4 erhältlichen Bromacetylene 7 mit 2 Mol 8 zugänglich. Die Reaktionsfolge ermöglicht den Aufbau neuer Retinoide mit Eninstruktur ausgehend von Retinal.
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    Darstellung und Eigenschaften von β-Phospha-trimethincyanin-Farbstoffen mit Indolin-EndgruppenHerrn Prof. Dr. Karl Dimroth zum 70. Geburtstag gewidmet. (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 2072-2094 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Properties of β-Phospha-trimethinecyanine Dyes with Indoline End GroupsHerrn Prof. Dr. Karl Dimroth zum 70. Geburtstag gewidmet.Reaction of 1,3,3-trialkyl-2-methyleneindolines 4 and 5 with phosphorus(III) halides yields, by a twofold nucleophilic substitution, the halogeno-phosphanes 6a - c, which in turn react with tri-methyloxonium tetrafluoroborate to give the β-phospha-trimethinecyanine dyes 3a, b. These β-phospha-cyanines 3a, b are the first higher-methinylogous representatives of the phospha-monomethinecyanine dyes 1, synthesized in 1964 by Dimroth and Hoffmann as the first compounds containing phosphorus in the oxidation state + 3 and with coordination number 2.  -  The 1H-, 13C-, 31P-NMR- as well as the UV/VIS spectra of these β-phospha-cyanines 3a, b and of the analogous β-“carba”-, β-aza- and β-arsa-trimethinecyanines are discussed with respect to their constitution, configuration, and π-electron-density distribution.
    Notes: Durch Umsetzung der 1,3,3-Trialkyl-2-methylenindoline 4 und 5 mit Phosphor(III)-halogeniden werden durch zweifache nucleophile Substitution die Halogenphosphane 6a - c erhalten, die beim Umsatz mit Trimethyloxonium-tetrafluoroborat die β-Phospha-trimethincyanin-Farbstoffe 3a, b ergeben. Diese β-Phospha-cyanine 3a, b sind die ersten höher-methinylogen Vertreter der 1964 von Dimroth und Hoffmann dargestellten Phospha-monomethincyanine  -  den ersten Verbindungen mit Phosphor in der Oxidationsstufe + 3 und mit der Koordinatonszahl 2.  -  Die 1H-, 13C-, 31P-NMR- und die UV/VIS-Spektren der β-Phospha-cyanine 3a, b und der analogen β-,„Carba“-, β-Aza- und β-Arsa-trimethincyanine werden in bezug auf Konstitution, Konfiguration und π-Elektronendichte-Verteilung diskutiert.
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  • 90
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    Zum Mechanismus der reduktiven Eliminierung substituierter Biphenyle aus cis-Bis(aryl)bis(triphenylphosphan)platin(II)-Verbindungen (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 928-937 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Mechanism of the Reductive Elimination of Substituted Biphenyls from cis-Bis(aryl)bis(triphenylphosphane)platinum(II)-CompoundsThe compounds cis-[Pt(PPh3)2(4-CH3O-C6H4)2], cis-{Pt(PPh3)2[4-(CH3)2N-C6H4]2, cis-{Pt(PPh3)2[4-(CH3)2N - C6H4](4-CH3O-C6H4)}, cis-{Pt(PPh3)2[4-(CH3)2N - C6H4](C6H5)} and cis-[Pt(PPh3)2(4-CH3O - C6H4)(C6H5)] were synthesized and the temperatures of reductive elimination of substituted biphenyls measured by differential calorimetry. Linkage between the two phenyl rings to form the biphenyl system occurs exclusively at the carbon atoms bonded directly to platinum.
    Notes: Die Verbindungen cis-[Pt(PPh3)2(4-CH3O-C6H4)2], cis-{Pt(PPh3)2[4-(CH3)2N-C6H4]2, cis-{Pt(PPh3)2[4-(CH3)2N - C6H4](4-CH3O-C6H4)}, cis-{Pt(PPh3)2[4-(CH3)2N - C6H4](C6H5)} und cis-[Pt(PPh3)2(4-CH3O - C6H4)(C6H5)] wurden synthetisiert und ihre Zersetzungs-Temperaturen der reduktiven Eliminierung substituierter Biphenyle differential-kalorimetrisch gemessen. Die Verknüpfung zum Biphenyl-System erfolgt ausschließlich zwischen den unmittelbar an das Platin gebundenen Kohlenstoff-Atomen beider Phenyl-Ringe.
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    Einstufensynthese von 2,4-Bis(sec-alkylamino) -6-halogen-3-pyridincarbonitrilenHerrn Prof. Dr. W. Lüttke zum 60. Geburtstag gewidmet. (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 946-953 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A One-step Synthesis of 2,4-Bis(secalkylamino)-6-halo-3-pyridinecarbonitrilesThe title compounds, e. g. 2a-c or 7, are obtained by reaction of malononitrile (1) with sec-alkyl halides/aluminium chloride (except the alkyl fluorides) at room temperature. From these the corresponding 2,4-bis(sec-alkylamino) pyridines may be conveniently prepared. With hydrogen bromide, 1 or its “dimer” 10 (R = H) 2,4-diamino-6-bromo-5-pyridinecarbonitrile (17) is formed.
    Notes: Malonsäuredinitril (1) liefert mit sec-Alkylhalogniden/Aluminiumchlorid (mit Ausnahme der Alkylfluoride) bei Raumtemperatur die Titelverbindungen (z. B. 2a-c Oder 7. Diese lassen sich glatt in die entsprechenden 2,4-Bis(sec-alkylamino)pyridine überführen. 1 oder das aus 2 Molekülen 1 gebildete 10b mit R = H geben mit Bromwasserstoff 2,4-Diamino-6-brom-5-pyridincarbonitril (17).
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    Masthead (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980) 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198019800701
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    Tetra- und pentacyclische Tricyclo[4.1.0.02,7]hept-3-en-Derivate; Abfangprodukte des Tricyclo [4.1.0.0.2,7]hepta-3,4-diensHerrn Professor Dr. Rolf Huisgen zum 60. Geburtstag gewidmet. (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 980-996 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Tetra- and Pentacyclic Tricyclo[4.1.0.02,7]hept-3-ene Derivatives; Trapping Products of Tricyclo[4.1.0.02,7]hepta-3,4-dieneHerrn Professor Dr. Rolf Huisgen zum 60. Geburtstag gewidmet.Reaction of 7,7-dibromotetracyclo[4.1.0.02,4.03,5]heptane (4) with methyllithium generates tricyclo[4.1.0.02,7]hepta-3,4-diene (7) as a reactive intermediate having diradical character, which either polymerizes or is trapped by suitable reagents such as styrene, 1,1-diphenylethene, butadiene, cyclopentadiene, furan, 1,3-cyclohexadiene, and cycloheptatriene. The products are the tetra- or pentacyclic compounds 8-10 and 12-14, 17, respectively, and contain the tricyclo[4.1.0.02,7]hept-3-ene system. Unequivocal evidence concerning the structure of these products follows from the 13C-NMR spectra. While butadiene and 7 form a 1,2-adduct, the vinyl cyclobutane derivative 10, cyclic 1,3-dienes provide 1,4-adducts, which presumably do not ensue from a one step process, but are the result of the collapse of a diradical intermediate. - The double bonds of 8 and 13 can be hydrogenated by means of diimine. Dibromcarbene adds to the double bond of 8 to give the spiro[2,3]hexane derivative 25.
    Notes: Die Umsetzung von 7,7-Dibromtetracyclo[4.1.0.02,4.03,5]heptan (4) mit Methyllithium erzeugt Tricyclo[4.1.0.02,7]hepta-3,4-dien (7) als reaktive Zwischenstufe mit Diradikalcharakter, die entweder polymerisiert oder durch Styrol, 1,1-Diphenylethen, Butadien, Cyclopentadien, Furan, 1,3-Cyclohexadien und Cycloheptatrien abgefangen wird. Daraus resultieren die tetra- und penta-cyclischen Verbindungen 8-10 bzw. 12-14, 17, die das Tricyclo[4.1.0.02,7]hept-3-en-System enthalten. Eindeutige Strukturmerkmale dieser Produkte spiegeln sich in ihren 13C-NMR-Spektren. Während Butadien mit 7 ein 1,2-Addukt, das Vinylcyclobutan 10, hervorbringt, liefern cyclische 1,3-Diene 1,4-Addukte, die wahrscheinlich nicht auf einstufigem Weg entstehen, sondern über ein intermediäres Diradikal. - Mit Hilfe von Diimin lassen sich die Doppelbindungen in 8 und 13 absättigen. Dibromcarben lagert sich an die Doppelbindung in 8, wobei das Spiro[2,3]hexan-Derivat 25 ensteht.
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    Umlagerung von Bis(amino)sulfoniumsalzen (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1046-1054 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Rearrangement of Bis(amino)sulfonium SaltsOn reaction with tertiary amines the amino(succinimido)sulfonium salts 4a  -  f rearrange with migration only of the succinimido moiety. Different amounts of the products 6 (from a 1,2-migration) and 7 (from a 2,3-migration) are formed depending on the amino group of the sulfonium salt 4.
    Notes: Die Amino(succinimido)sulfoniumsalze 4a  -  f lagern sich bei der Einwirkung von tertiären Aminen um. Dabei wandert ausschließlich der Succinimidrest. In Abhängigkeit von der Aminogruppe entstehen verschiedene Mengen der Produkte 6 aus einer 1,2- und 7 aus einer 2,3-Umlagerung.
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    Cyclisierung von 1-Phosphoryl-substituierten 2-Vinylcyclopropanen durch Elektrophile (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1028-1045 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cyclisation of 1-Phosphoryl-substituted 2-Vinylcyclopropanes by ElectrophilesUnder the influence of bromine or hydrogen bromide, the 2-isopropenylcyclopropylphosphonates and -phosphinates (Z)-1a  -  c undergo cyclisation to the 3,2λ5-oxaphosphabicyclo[3.1.0]-hexan-2-ones 6 and 7a  -  c, respectively. The analogous reactions of the phosphine oxide (Z)-1d end at the stage of the bicyclic phosphonium salts 6d and 7d. The structure of 6d was proved by X-ray structure analysis. The isomeric isopropenylcyclopropanes (Z)-1a  -  c do not possess the steric requirements for cyclisation, so their only reaction with hydrogen bromide is the slow saponification of the ester group, whilst the oxaphosphetane 14 is the sole identifiable product of the bromine addition to (E)-1a.  -  The 2-vinylcyclopropylphosphonates (E)- and (Z)-16 only add Br2 and HBr in the usual manner at the double bond.
    Notes: Unter dem Einfluß von Brom und Bromwasserstoff cyclisieren die 2-Isopropenylcyclopropyl-phosphonate und -phosphinate (Z)-1a  -  c zu den 3,2λ5-Oxaphosphabicyclo[3.1.0]hexan-2-onen 6 bzw. 7a  -  c. Die analogen Reaktionen des Phosphinoxides (Z)-1 d bleiben auf der Stufe der bicyclischen Phosphoniumsalze 6d bzw. 7d stehen. Für 6d wurde eine Röntgenstrukturanalyse durchgeführt. Die isomeren Isopropenylcyclopropane (E)-1 a  -  c, denen die sterischen Voraussetzungen zur Cyclisierung fehlen, reagieren dagegen mit Bromwasserstoff nur unter langsamer Verseifung der Esterfunktion, während aus (E)-1 a mit Brom das Oxaphosphetan 14 als einziges identifizierbares Produkt erhalten wird.  -  Die 2-Vinylcyclopropylphosphonate (E)- und (Z)-16 addieren Brom oder Bromwasserstoff nur in üblicher Weise an der Doppelbindung.
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    Eine einfache Synthese für (Acylphenylamino)sulfoniumsalze, ein Weg zu o-(Methylthiomethyl)aniliden (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1064-1074 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A Facile Synthesis of (Acylphenylamino)sulfonium Salts, an Entry to o-(Methylthiomethyl)anilidesNitrilium salts 1 and dimethyl sulfoxide (2) react even at low temperatures to give (acylamino)sulfonium salts 5. The intermediate  -  detected spectroscopically  -  is assigned the structure of an iminooxysulfonium salt 3. Besides 5 the phenylsulfonium salts 10 are also formed from 3. Methylthiomethylated anilides 9 are obtained from 5 by a 2,3-rearrangement.
    Notes: Bereits bei tiefen Temperaturen reagieren Nitriliumsalze 1 und Dimethylsulfoxid (2) zu (Acylamino)sulfoniumsalzen 5. Der spektroskopisch nachweisbaren Zwischenstufe wird die Konstitution eine Iminooxysulfoniumsalzes 3 zugeordnet. Neben 5 werden aus 3 teilweise auch Phenylsulfoniumsalze 10 gebildet. Aus 5 sind durch 2,3-Umlagerung methylthiomethylierte Anilide 9 zugänglich.
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    Zur Chemie des meso-Tetramethylporphins, II. Über Kondensationsprodukte von Carbonylverbindungen und Alkoholen mit Nickel(II)-meso-tetramethylporphin (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1082-1107 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Chemistry of meso-Tetramethylporphine, II1)  -  Condensation Products of Carbonyl Compounds and Alcohols with Nickel(II)-meso-tetramethylporphineThe condensation products of nickel(II)-meso-tetramethylporphine (Ni-TMP, 1 a) with aldehydes or their acetals are described. In this simple way the diporphinylmethanes 2 a  -  d covalently linked at their β,β'-position have been obtained together with trimers and polymers (3 and 4). Reaction of 1 a with benzyl alcohol or diphenylmethanol produces the porphine derivatives 5 a and 5 b, which are analogs of diphenyl- and triphenylmethane, and the disubstituted derivatives 6 a and 6 b as by-products. Reaction of 1 a with lauraldehyde affords the polymer 7. In this way it is possible to synthesize porphine derivatives which are suitable for the construction of systems with monomolecular layers. The porphine derivatives, which are analogous to diphenyl- and triphenyl-methane are characterized by spectroscopy and their conformation in solution, which resembles the spatial structure of the porphyrine units in a bacteriochlorophyll a-protein complex is discussed.
    Notes: Es werden die Kondensationsprodukte von Nickel(II)-meso-tetramethylporphin (Ni-TMP, 1 a) mit Aldehyden oder deren Acetalen beschrieben. Auf einfache Weise werden so die β,β'-verknüpften Diporphinylmethanderivate 2a  -  d neben Tri- und Polymeren (3 und 4) erhalten. Die Umsetzung von 1 a mit Benzylalkohol und Diphenylmethanol führt zu den Diphenyl- und Triphenylmethan-analogen Porphinderivaten 5 a und 5 b. Als Nebenprodukte erhält man die disubstituierten Derivate 6 a und 6 b. Setzt man 1 a mit Laurinaldehyd um, so ergibt sich das Polymere 7. Diese Reaktion eröffnet den Weg zur Synthese von Porphinderivaten, die für den Aufbau von Systemen aus monomolekularen Schichten geeignet sein sollten. An Hand der Spektren wird die Konstitution der Diphenyl- und Triphenylmethan-analogen Porphine abgeleitet und deren Konformation in Lösung diskutiert, die der Anordnung der Porphyrineinheiten in einem Bacteriochlorophyll-a-Protein-Komplex ähnelt.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198019800709
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    Zur Stereochemie der Carbonsäuredianion-Aldehyd-Addition unter kinetisch und thermodynamisch kontrollierten Bedingungen  -  Reindarstellung und Konfigurationszuordnung von 2,3-disubstituierten threo- und erythro-3-Hydroxycarbonsäuren (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1108-1134 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stereochemistry of the Addition of Carboxylic Acid Dianions to Aldehydes under Kinetic and Thermodynamic Control  -  Synthesis and Configurational Assignment of 2,3-Disubstituted threo- and erythro-3-Hydroxycarboxylic AcidsUnder kinetically controlled conditions ( - 50°C, 10 min) the carboxylic dianions 2 add to aldehydes 3 to give the threo/erythro-adducts 4/5 (Scheme 1); the threo-selectivity markedly increases with the bulkiness of the substituents of 2 or 3 and decreases with the charge/radius ratio of the counter-ions of 2. From these results a syn-transition state with a HOMO-LUMO interaction between 2 and 3 is derived (Scheme 3). For appropriate substituents a far higher threo-selectivity is observed under thermodynamically (22  -  50°C, 1  -  3 days) than under kinetically controlled conditions. We describe the isolation of the hydroxy acids 6 and 7, which are formed from 4 and 5 on acidic hydrolysis, and show how their configurations can be unambiguously assigned on the basis of 1H-NMR data.
    Notes: Unter kinetisch kontrollierten Bedingungen ( - 50°C, 10 min) vereinigten sich die Carbonsäuredianionen 2 mit Aldehyden 3 zu den threo/erythro-Addukten 4/5 (Schema 1), wobei der threo-Anteil mit der Raumerfüllung der Substituenten an 2 oder 3 stark ansteigt und mit dem Ladung/Radius-Verhältnis der zu 2 gehörigen Gegenionen ebenso deutlich abfällt. Daraus wird auf einen syn-Übergangszustand mit cycloadditionsähnlicher HOMO-LUMO-Wechselwirkung zwischen 2 und 3 geschlossen (Schema 3). Unter thermodynamischer Kontrolle (22 - 50°C, 1  -  3 Tage) erhöht sich bei geeigneter Substitution die threo-Selektivität gegenüber der kinetischen Kontrolle beträchtlich. Es wird die Reindarstellung der aus 4 und 5 durch saure Hydrolyse entstehenden Hydroxysäuren 6 und 7 beschrieben, deren Konfiguration auf Grund von 1H-NMR-Daten zweifelsfrei zugeordnet werden kann.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198019800710
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    Konformation und Rotation bei Diphenylallyl-Verbindungen (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1135-1171 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Conformations and Rotational Barriers of 1,3-Diphenylallyllithium CompoundsThe phenyl substituents of the 1,3-diphenylallyl anions 10 (gegenion lithium, solvent tetra-hydrofuran) can exist in the exo,exo-, endo,exo- and/or endo,endo-conformations. We have investigated the influence of substituents R at C2 on the equilibria of these solvent separated ion pairs. While 10 a (R = H) is the only one to exist predominantly in the exo,exo-conformation, and in 10 b and c (R = CH3 and CN, respectively) the endo,exo-conformers predominate, in 10 d, e and f (R = C2H5, C6H5 and iPr, respectively) there is increasing preference for the endo,endo-conformation, which in 10 g (R = tBu) is the dominant (≥ 95%) conformation. A vast congestion in the endo,endo-conformation is avoided by a rotation of the phenyl rings out of the plane of the allyl carbon atoms, and an expansion of the sp2 angles in the allyl moiety. The rotational barriers around the allyl anion bonds decrease from 19.1 kcal · mol-1 (10 a) to 12.5 kcal · mol-1 (10 f). Since this trend parallels to the above mentioned shift of the equilibria, it is due to ground state
    Notes: Bei den 1,3-Diphenylallyl-Anionen 10 (Gegenion Lithium, Lösungsmittel Tetrahydrofuran) können die beiden Phenylsubstituenten in der exo,exo-, endo,exo- und/oder endo,endo-Konformation vorliegen. Wir untersuchten den Einfluß von Substituenten R an C2 auf das Konformeren-Gleichgewicht dieser solvens-getrennten Ionenpaare. Während 10 a (R = H) als einziges die exo,exo-Konformation bevorzugt und bei 10 b (R = CH3) und 10 c (R = CN) das endo,exo-Konformere überwiegt, gewinnt bei 10 d, e und f (R = C2C5, C6H5 und iPr) die endo,endo-Konformation ständig an Bedeutung, um bei 10 g (R = tBu) ausschließlich (≥ 95%) vorzuliegen. Die in dieser Konformation zu erwartende sterische Hinderung wird dadurch vermieden, daß die Phenylringe aus der Ebene der Allyl-C-Atome herausgedreht und die Winkel im Allylteil aufgeweitet sind. Mit der Gleichgewichtsverlagerung nehmen die Rotationsbarrieren um die Allyl-Anion-Bindungen von ΔG±273°C = 19.1 kcal · mol-1 bei 10 a auf 12.5 kcal · mol-1 bei 10 f ab, so daß die Destabilisierung des Grundzustandes für diesen Trend verantwortlich ist. Gegenioneffekte beeinflussen die Rotationsbarrieren nur unwesentlich (10 a, b), bzw. gar nicht  -  ganz im Gegensatz zum unsubstituierten Allyl-“Anion”. Damit eignen sich die in dieser Arbeit ermittelten Werte erstens für einen Vergleich mit den topologisch identischen Kationen und Radikalen. Zum zweiten läßt sich eine untere Grenze für die Rotationsbarriere im unsubstituierten, freien Allyl-Anion angeben (ΔG±273°C = 19.1 kcal · mol-1), sowie abschätzen, daß diese Barriere sehr nahe bei Werten um 26 kcal · mol-1 liegen muß. Solche Werte werden auch mit Hilfe von STO-3G- und 4-31-G-MO-Rechnungen erhalten.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198019800711
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    Zur Bildung und Reaktivität di-tert-alkylsubstituierter Phenylalkene (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1207-1215 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Formation and Reactivity of Di-tert-alkyl Substituted PhenylalkenesMolecular rearrangements occur during the attempted syntheses of α-bromo-β,β-di-tert-alkylstyrenes; the resulting structures are elucidated. A hydrocarbon dimer with allenic structure accompanies the formation of the Grignard reagent from an α-bromostyrene with bulky substituents.
    Notes: Bei Versuchen zur Synthese von α-Brom-β,β-di-tert-alkylstyrolen laufen molekulare Umlagerungen ab; die Strukturen der Reaktionsprodukte wurden aufgeklärt. Bei einem sperrig substituierten α-Bromstyrol ist die Bildung der Grignardverbindung von der eines dimeren Kohlenwasserstoffs mit Allenstruktur begleitet.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198019800805
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