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  • 1970-1974  (5,954)
  • 1890-1899
  • 1972  (5,954)
  • Chemistry  (5,475)
  • Life and Medical Sciences  (479)
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  • 1970-1974  (5,954)
  • 1890-1899
Year
  • 101
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 11 (1972), S. 2179-2186 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The structural behavior of hydrochlorides of poly-L-lysine and tetraglycine depends on water vapor pressure. At low relative humidities, structural rearrangements are slow. Water molecules catalyze these structural rearrangements; thus, in tetraglycine 1 H2O molecule per 10 peptide residues. Some general aspects of the mechanism of the hydration mobility in peptide structures are discussed.
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  • 102
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Although native B-type starch loses its sharp X-ray pattern on strong drying, the wet Nägeli amylodextrin prepared from such starch gives a sharp B-pattern, that is only slightly reduced in sharpness by complete drying. Nägeli amylodextrin dried admixed with a noncrystalline “filler” (e.g., starch sirup) gives an X-ray pattern essentially identical to that of the wet amylodextrin, except that the 16-Å (No. 1) ring is greatly reduced in sharpness and intensity. Failure of the B-structure to collapse during drying indicates that water is not intercalated between turns of a helix or otherwise required to maintain the geometry and packing arrangement of the starch molecular chains. Rather, for native starch granules or amylose fibers, water relieves intercrystallite strains and consequent crystallite distortion induced by strong drying. For Nägeli amylodextrin, the small molecules of starch sirup can penetrate the interstices between crystallites and prevent strain build-up during drying. For native starch granules, the interstitial regions are gel-like in character and less permeable to starch sirup molecules. A model for B-starch is proposed, that employs intertwined (double) helices.
    Additional Material: 13 Ill.
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  • 103
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 11 (1972), S. 2309-2316 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The circular dichroism (CD) spectra of poly-L-proline and of poly-L-glutamic acid and poly-L-lysine in their charged states have been studied as a function of temperature. The variation of CD spectra with temperature is inconsistent with the assignment of the spectrum of such charged polypetides to an unordered chain conformation, but does support our earlier assignment to a locally ordered structure - what we have called the extended helix conformation. These results also strengthen our previous assignment of the CD spectrum of an unordered chain, and indicate that three conformational states (α-helix, extended helix, and unordered) should be incorporated in our thinking about conformational transitions in polypeptides.
    Additional Material: 5 Ill.
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  • 104
    Electronic Resource
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    New York : Wiley-Blackwell
    Biopolymers 11 (1972), S. 2349-2356 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The existing experimental data on prebiotic nonenzymic biopolymer synthesis is used to construct a model which shows autocatalysis and highly nonlinear behavior. It is shown that far from thermodynamic equilibrium such systems may exhibit multiple steady states favoring the enhancement of the polymer population in the medium. The role of step by step chain propagation and template directed autocatalysis are studied and contrasted.
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  • 105
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    New York : Wiley-Blackwell
    Biopolymers 11 (1972), S. 2357-2364 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Specific volumes at 25° of aqueous solutions of poly(N-methyl acrylamide) and poly-(ethylene oxide) have been measured, and the data obtained is compared with corresponding data on low-molecular-weight compounds. The results support the notion, that the volume changes following the interaction between aliphatic groups and water are positive. They are discussed with particular reference to pressure effects on protein conformations.
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  • 106
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    New York : Wiley-Blackwell
    Biopolymers 11 (1972), S. 2365-2379 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The conformational states of single-stranded calf thymus DNA were probed using the tmeperature-jump kinetic technique. A rapid decrease in transmission at 260 nm followed by a broad relaxation spectrum was observed for single-stranded DNA at 0.15M KCI, pH, 6.5 at 25°. The relaxation spectrum could also be detected as a hydrogen ion release. Sonicated samples of 103,000 daltons showed identical relaxation kinetics as unsonicated samples. The relaxation kinetics were studied as a function of temperature, pH, and salt concentration and could be interpreted as representing the melting of short, isolated folded segments. The rapid process that could not be kinetically resolved is interpreted as single-strand unstacking. Upon the addition of excess MgCl2 at pH 7.0, a hydrogen ion release from single-stranded DNA was observed that was 3.5 times greater than that observed for a comparable sample of native DNA. Evidence is presented which indicates that charge-pairs exist in folded segments that are A-T rich. There was no kinetic evidence of structures in single-stranded DNA other than single-stranded stacking and short isolated folded regions.
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  • 107
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    New York : Wiley-Blackwell
    Biopolymers 11 (1972), S. 2483-2491 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: For an ideal one-dimensional solid, the low-temperature specific heat, C, is proportional to temperature T1, for an ideal two-dimensional solid C is proportional to T2. We have observed such one- and two-dimensional behavior in alpha- and beta-poly(L-alanine) in the temperature range 1.5-20°K (also intermixed with a three-dimensional behavior). A specific heat anomaly has also been observed. These measurements are important in evaluating the effective elastic constants, including hydrogen bonding, of the biopolymers. They also provide essential information for vibrational theories of poly(L-alanine), which up until now have been based on high-energy data.
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  • 108
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    New York : Wiley-Blackwell
    Biopolymers 11 (1972), S. 2533-2536 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A method has been developed for labeling proteins by acetylation without appreciable loss in biological activity.
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  • 109
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    New York : Wiley-Blackwell
    Biopolymers 11 (1972), S. 2563-2575 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A dc conductivity study of native and denatured samples of sodium salts of calf thymus DNA in the solid state was performed at different temperatures and water content. From the results obtained it appears that the major carrier of conductivity is either electronic or ionic, depending upon the temperature of the sample, the water content, and the fact that the conductivity of native samples is higher than that of the denatured ones. These results have been confirmed by dc conductivity studies of poly U and poly A.
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  • 110
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    New York : Wiley-Blackwell
    Biopolymers 11 (1972), S. 2601-2624 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The rate of breakage of duplex DNA molecules by laminar flow through a capillary has been studied. For λb2b5c DNA (molecular wt., M = 25 × 106) the point at which breakage occurs is normally distributed around the center of the molecule with a standard deviation of 12.5% of the molecular length. At constant shear stress or shear rate, the breakage rate is independent of ionic strength. Thus, shear induced local denaturation is not a rate limiting, preliminary step in breakage. In experiments at constant temperature with varying solvent viscosity (controlled by added sucrose) the breakage rate is a function of shear rate, not of shear stress. The rate of opening of hydrogenbonded circles into linear molecules by hydrodynamic shear is also shown to be a function of shear rate and not of shear stress. The breakage rate at constant shear rate is not greatly dependent on temperature. The shear rate required to achieve breakage is inversely proportional to M1,2. The breakage rate constant, k varies as a very high power of the shear rate; at 25°C, d In k/d In Gm ∼ 15; at 10°C, d In k/d In Gm ∼ 26, where Gm is the maximum shear rate at the capillary wall. The unexpected result that breakage rate is mainly dependent on shear rate, not shear stress, supports a model in which the DNA molecule is distorted with a driving force which depends on the hydrodynamic shear stress, ηG, but the rate limiting step is segment diffusion into a highly extended configuration. The characteristic time to achieve this configuration is proportional to solvent viscosity, η, hence the breakage rate is dependent on ηG/η or G, the shear rate.
    Additional Material: 9 Ill.
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  • 111
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The dichroic ratio spectra of TMV and four of its mutants (YTAMV, GTAMV, HR, and CV4) were determined from 320 to 240 nm. Measurements were also made on particles of ATMV (TMV protein reconstituted with polyadenylic acid) and rods of repolymerized TMV, YTAMV and GTAMV protein, respectively. These cylindrical molecules were oriented in a flow gradient with their degree of orientation being determined from anisotropic light scattering measurements. Taking length distributions into account, the dichroic ratios were then extrapolated to values characteristic of perfect particle alignment.Due to the large number of overlapping absorbing bands in the whole viruses, it is very difficult to separate out specific contributions to the total spectra. Since, however, the spectra for the whole viruses were similar, this would suggest an overall likeness in structure for all the virus particles studied. Because the repolymerized proteins did not have the four RNA chromophoric groups present, their spectra would be more sensitive to protein contributions to the total spectrum. Repolymerized rods of YTAMVP yielded results similar to those for TMVP, while the spectrum for repolymerized rods of GTAMVP was significantly different from that obtained for TMVP.Dichroic ratio spectra of the nucleic acids, as they exist within the whole particles, were also calculated by subtracting protein absorptivities from their respective viral absorptivities. The spectra indicates similar results for the various nucleic acids in all the particles studied.
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  • 112
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    New York : Wiley-Blackwell
    Biopolymers 11 (1972), S. 2439-2459 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In order to obtain information on the binding forces involved in the formation of the complex proflavine-DNA by the stronger process I, the stability of the complexes was investigated in the presence of various organic solvents, methanol, ethanol, n-propanol, isopropanol, formamide, dimethyl sulfoxide, p-dioxane, glycerol, and ethylene glycol. Quantitative data on binding in terms of K/n and r were obtained by means of absorption and fluorescence spectra, as well as by a thermal denaturation technique.All organic solvents used decrease the binding ability of the dye. The effectiveness of the solvents increases with their hydrocarbon content, but can hardly be related to their dielectric constant. The complex formation is effectively suppressed by organic solvent concentrations, in which DNA still preserves its double-helical conformation. These results demonstrate the importance of hydrophobic forces in the formation of the complex proflavine-DNA in aqueous solution.The similarity in spectroscopic properties of proflavine bound to DNA by process I and the same dye dissolved in an organic solvent make it possible to interpret the observed red shift of the long-wavelength absorption peak as being due to the interaction of the dye molecules with the less polar environment.The same behavior was found for other dyes capable of intercalation like purified trypaflavine, phenosafranine and ethidium bromide. However, intercalation is not a necessary condition, as it was shown in the case of pinacyanol, which binds only at the surface of DNA.
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  • 113
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    Biopolymers 11 (1972), S. 2521-2532 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Enthalpy changes [as determined by differential scanning calorimetry (DSC)] and optical rotation changes over the helix → coil transition were measured for various gelatin solutions and films. From these studies it has been concluded that: (1) a linear correlation between ΔH and Δ[α] exists for gelatin solutions, independent of the temperature at which gelation occurred; (2) the amount of triple helical structure regained when a melted gelatin solution is quenched can be calculated from DSC data, but the values obtained will be dependent on assumptions about the number and strength of hydrogen bonds; (3) the anomalously high levorotation values found for cold-dried films of gelatin do not reflect the presence of an extraordinarily large amount of triple helical structure; rather, the large rotations appear to be the result of orientation of helices in the plane of the film.
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  • 114
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    Biopolymers 11 (1972), S. 2577-2589 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The adsorption of single-stranded polynucleotides and double-helical DNA on the dropping mercury electrode has been studied with the aid of Breyer's alternating current (a.c.) polarography. Our results indicate that all three constituents of polynucleotides (residues of bases, sugar, and phosphoric acid) are involved in the adsorption. At neutral pH their participation in adsorption depends on the ionic strength, the potential of the electrode, and the conformation of the polynucleotide in the solution.At an ionic strength of about 0.1, double-helical DNA is adsorbed electrostatically on a positively charged electrode surface by inadequately masked negative charges of the phosphate groups. At a higher ionic srength (about 0.5), this electrostatic adsorption is no longer detectable by using a.c. polarography; under these conditions it is probable that native DNA is adsorbed around the potential of the electrocapillary maximum with the aid of sugar residues and a few bases. Single-stranded polynucleotides, on the other hand, are primarily adsorbed by means of the bases.Desorption of double-helical DNA occurs around a potential of -1.2 V against SCE. At this potential, the helical regions of single-stranded polynucleotides are also desorbed. Desorption of the disordered regions of single-stranded polynucleotides occurs at more negative potentials. Adsorption and desorption of a small number of bases released from double-helical DNA was evident in the a.c. polarograms only at elevated temperature, or at room temperature after degradation of DNA by sonication.
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  • 115
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    New York : Wiley-Blackwell
    Biopolymers 11 (1972), S. 2625-2631 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 116
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    Biopolymers 11 (1972) 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 117
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The virtual bond scheme set forth in preceding papers for treating the average properties of polyriboadenylic acid (poly rA) is here applied to the calculation of the unperturbed mean-square end-to-end distance of polydeoxyriboadenylic acid (poly dA). The modifications in structure and in charge distribution resulting from the replacement of the hydroxyl group at C2′ in the ribose residue by hydrogen in deoxyribose produce only minor modifications in the conformational energies associated with the poly dA chain as compared to those found for poly rA. The main difference is manifested in the energy associated with rotations about the C3′-O3′ bond of the deoxyribose residue in the C2′-endo conformation; accessible rotations are confined to the range between 0° and 30° relative to the trans conformation, whereas in the ribose unit the accessible regions comprise two ranges centered at approximately 35° and 85°. The characteristic ratio 〈r2〉0/nl2 calculated on the basis of the conformational energy estimates is ≈9 for the poly dA chain with all deoxyribose residues in the C3′-endo conformation and ≈21 with all residues in the C2′-endo form. Satisfactory agreement is achieved between the theoretical values and experimental results on apurinic acid by treating the poly dA chain as a random copolymer of C3′-endo and C2′-endo conformational isomers present in a ratio of ∼1 to 9.
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  • 118
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    Biopolymers 11 (1972), S. 137-144 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The potentiometric titration curves of carboxymethylcellulose, which has a relatively stiff backbone, and also of poly(D-glutamic acid) in the helical region are compared with the theoretical curves calculated assuming that the polyions are rods and have smeared charges on their surfaces. For carboxymethylcellulose good agreement is observed when its charge density is high, whereas as the charge density decreases the calculated curves deviate from the observed ones. The main reason for the disagreement at low charge densities may be attributed to the flexibility of the polymer backbone. For helical poly(D-glutamic acid) satisfactory agreement between calculated and observed curves is found if a radius thicker than the realistic radius is employed. The reason for the excessively large radius may be attributed to the inapplicability of the smeared charge model.
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  • 119
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The sum E of the packing and conformation energies of the crystals of DL-acetylleucine N-methylamide (ALNMA) and DL-acetyl-α-amino-n-butyric acid N-methylamide (ABAMA) is calculated as a function of the crystallographic parameters and the conformational angles. The intermolecular energy is assumed to be the pairwise sum of nonbonded and electrostatic atomic interactions, while both these terms and intrinsic terms describing barriers of internal rotation contribute to the intramolecular energy. For ALNMA E is minimized with respect to 18 parameters: the minimum found when starting from the experimental structure agrees with this within 0.07 Å and 3°, except for one angle which deviates by 6° the average deviations of the atomic coordinates are \documentclass{article}\pagestyle{empty}\begin{document}$ |\overline {\Delta x|} = 0.02,|\overline {\Delta y|} = 0.07,|\overline {\Delta z|} = 0.08 $\end{document} Å. Another minimum with about the same energy shows slightly worse agreement. A comparison between different sets of nonbonded functions is made. The prediction of conformation and intermolecular packing of ABAMA is attempted on the basis of the knowledge of the unit cell and the space group. In agreement with available experimental data it is found that only one-di-mensional arrays of molecules linked by pairs of hydrogen bonds are compatible with the unit cell. The more stable of two possible conformations of the main chain agrees approximately with the experimental conformation. The calculation is not conclusive with regard to the side-chain conformation and the packing of non-hydrogen-bonded molecules.
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  • 120
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    Biopolymers 11 (1972), S. 185-196 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Several β,N-alkyl L-asparagines were prepared from the phthalyl and benzyloxycarbonyl derivatives. High-molecular-weight poly-β,N-benzyl L-asparagine and poly-β,N-(1)-phenethyl L-asparagine were prepared from the corresponding N-carboxyanhy-drides. From the results obtained by a study of the infrared absorption spectra and the optical rotatory dispersion, poly-β-N-benzyl L-asparagine was found to be a random coil structure in dichloroacetic acid and the optical rotatory dispersion curves gradually changed into the left-handed α-helix structure when chloroform was added to the solution. The coil-to-helix transition was observed in the vicinity of 20% dichloroacetic acid in a dichloroacetic acid-chloroform mixture. Poly-β,N-(d), (l), and (d + l, 1:1)(d + l, 1:1): mixed polymer containing the same weighed poly-β,N-(d) and (l)-(1)-phenethyl L-asparagines.-(1)-phenethyl L-asparagines showed a nearly constant specific rotation in the dichloroacetic acidchloroform solvent system. Poly-β,N-(dl)-(1)-phenethyl L-asparagine caused a gradual folding of the helix at dichloroacetic acid content of less than 20%.
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  • 121
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    Biopolymers 11 (1972), S. 235-250 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Temperature melting profiles of adenylyladenosine and cytidylylcytidine were examined by ultraviolet absorption, circular dichroism, and optical rotatory dispersion. They showed the following characteristics: profiles for different absorption wavelengths are identical as defined by least-squares computed optical and thermodynamic parameters; melting curves obtained by the three spectroscopic methods are likewise in all cases identical by a series of criteria; in terms of the operational equilibrium constant for base-stacking all van't Hoff plots are linear; absorption spectra and circular dichroism curves at a series of temperatures for both dinucleoside phosphates give excellent isosbestic points; a matrix-rank analysis of the family of complete spectra at different temperatures gives a value of two for the numbers of components in both cases. Four criteria are thus fulfilled of a two-state system for the stacking equilibrium. The results are not compatible with a multi-state scheme in which the substates are optically distinguishable. There is no measurable effect of ionic strength up to 1.0. In a presence of high concentrations of lithium chloride the criteria for two-state behavior are no longer fulfilled, and examination of infrared spectra gives evidence of complex formation by this salt, though not by sodium chloride. A destacking profile, similar to that observed on heating, is obtained by progressive addition of ethylene glycol to the solution. It is suggested that in dimers, though not in higher oligomers or polymers, the stacking equilibrium can be operationally regarded as a two-state system, and that the meaningful thermodynamic parameters can be extracted by analytical treatment, of the type here developed, of the melting profiles.
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  • 122
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    Biopolymers 11 (1972) 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 123
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    Biopolymers 11 (1972), S. 361-374 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Proflavine binding experiments were carried out with yeast rRNA, native and “unfolded” ribosomes; the binding constants and the number of binding sites were calculated by a spectroscopic method. The study of the intercalation complexes by fluorescence and electric dichroism shows the intercalation binding sites to involve two subtypes of sites, which could be related to different nucleotide composition and secondary structure of the rRNA regions, i.e., binding sites located in the (A + U)-rich single strands and binding sites located in the (G + C)-rich double-helical strands (fluorescence quenching sites). Electric dichroism of complexed proflavine is interpreted in terms of rRNA conformation within the ribosomes. The conclusions are in agreement with the ribosomal model of Cox and Bonanou and show that, according to this model, the base planes of the nucleotides are not all parallel in the native ribsome, but rather radiate around the folding axis of the ribonucleoprotein sheet.
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  • 124
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    Biopolymers 11 (1972), S. 1235-1258 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: We present CD spectra of four trinucleoside diphosphates, UpUpG, GpUpG, ApUpA, and ApUpG, of four single-stranded polymers, poly AC, poly GU, poly AU, and poly AdU, and of five double-stranded polymers, poly A:U, poly G:C, poly AU:AU, poly AdU:AdU, and poly GC:GC. The measured spectra are compared with empirical firstneighbor calculations. Our results, taken together with data from the literature, suggest that UpA and UpG sequences are relatively unstacked in a single-stranded RNA compared with these isolated dimers in solution. These sequences may influence the structure and function of natural RNAs. Our results on double-stranded RNAs indicate that the spectral changes which occur upon formation of a double helix are unique to the type of base pair involved and are relatively independent of sequence.
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  • 125
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    Biopolymers 11 (1972), S. 1289-1294 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 126
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    Biopolymers 11 (1972), S. 1311-1316 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 127
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    Biopolymers 11 (1972), S. 1357-1363 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Spectrophotometric measurements were made on the extent of binding of formaldehyde to polyuridylic acid under conditions of varying temperature and formaldehyde concentration. The data is interpreted in terms of a temperature-dependent stacking of the bases in poly U at 20°, but not at 40°C. A theory of cooperative stacking is developed which considers the base residues to be either non-bonded, non-bonded and methylolated, or stacked. The results indicate essentially non-cooperative base stacking under these conditions with an equilibrium constant for base stacking of 0.92 at 20°C.
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    Chemie in unserer Zeit 6 (1972), S. 66-68 
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    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 129
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    Chemie in unserer Zeit 6 (1972), S. 33-33 
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    Keywords: Chemistry ; Chemistry
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    Topics: Chemistry and Pharmacology
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  • 130
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    Chemie in unserer Zeit 6 (1972) 
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    Keywords: Chemistry ; Chemistry
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  • 131
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  • 132
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    Chemie in unserer Zeit 6 (1972) 
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    Keywords: Chemistry ; Chemistry
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  • 133
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    Chemie in unserer Zeit 6 (1972), S. 45-51 
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    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 6 Ill.
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  • 134
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    Chemie in unserer Zeit 6 (1972) 
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    Keywords: Chemistry ; Chemistry
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  • 135
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    Chemie in unserer Zeit 6 (1972), S. 147-153 
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    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 7 Ill.
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  • 136
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    Chemie in unserer Zeit 6 (1972), S. 65-65 
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    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 137
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  • 138
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    Chemie in unserer Zeit 6 (1972) 
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    Keywords: Chemistry ; Chemistry
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  • 139
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    Chemie in unserer Zeit 6 (1972), S. 1-16 
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 7 Ill.
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  • 140
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    Chemie in unserer Zeit 6 (1972), S. 17-26 
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 16 Ill.
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  • 141
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 474-480 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation of new Thiazyltrifluoride Derivatives by Si-N Bond Cleavage Reactions. Preparation of N.N'-Bis(difluorophosphoryl)sulfur Difluoride DiimideBy Si-N bond cleavage reactions with thiazyltrifluoride NSF2-N(CH3)2 (3) and NSF2-N(C2H5)2 (4) were prepared. (CH3)3Si-N=SF2=N-Si(CH3)3 (1) react with SF4 to yield NSF2-N=SF2 (5), with P2O3F4 to give O=PF2-N=SF2=N-PF2=O (6) and small amounts of (CH3)3Si-N=SF2=N-PF2=O (7). By reaction of 1 with dimethylamine and piperidine [CH3)3Si-N=]2S[N(CH3)2]2 (8) and [(CH3)3Si-N=]2S(NC5H10)2 (9) are formed.
    Notes: Durch Si-N-Spaltungsreaktionen mit Thiazyltrifluorid wurden NSF2—N(CH3)2 (3) und NSF2—N(C2H5)2 (4) dargestellt. Aus (CH3)3Si—N=SF2=N—Si(CH3)3 1) entsteht mit SF4 NSF2—N=SF2 (5), mit P2O3F4 O=PF2-N=SF2=N-PF2=O (6) neben geringen Mengen (CH3)3Si—N=SF2=N—PF2—O(7). Die Reaktionen von 1 mit Dimethylamin und mit Piperidin führt zu [(CH3)3Si-N=]2S[N(CH3)2]2 (8) bzw. zu [(CH3)3Si-N=]2S(NC5H10)2 (9).
    Additional Material: 2 Tab.
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  • 142
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 1-7 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Olefine Gold Complexes, VII. Hexamethyl Dewarbenzene and Gold(III)-chloride; Carbonium Ions as Intermediates in the Chlorination of Olefines with Gold(III)-chlorideCristalline exo(CH3)-6-chloro-1.2.3.4.5.6-hexamethylbicyclo[2.1.1]hexenyl-tetrachloroaurate (1) is formed as a stable compound up to about -20°, as well as the gold(I) complex 2 of hexamethyl dewarbenzene (HMDB) by the reaction of HMDB with gold(III)-chloride at low temperature. Under the same conditions tetrachloro-auric acid forms with HMDB cristalline 1.2.3.4.5.6-hexamethylbicyclo[2.1.1]hexenyl-tetrachloroaurate 4a/b as a (CH3)endo/exo mixture, which as well is stable up to about -20°.
    Notes: Bei der Reaktion von Hexamethyl-Dewarbenzol (HMDB) mit Gold(III)-chlorid bei tiefer Temperatur bildet sich exo(CH3)-6-Chlor-1.2.3.4.5.6-hexamethyl-bicyclo[2.1,1]hexenyl-tetrachloroaurat (1) als kristallisierbare, bis etwa -20° haltbare Substanz, sowie der Gold(I)-chlorid-Komplex des HMDB (2). Mit Tetrachlorogoldsäure entsteht aus HMDB unter den gleichen Bedingungen kristallines 1.2.3.4.5.6-Hexamethyl-bicyclo[2.1.1]hexenyl-tetrachloroaurat 4a/b als (CH3)endo/exo-Gemisch, welches ebenso bis etwa -20° beständig ist.
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  • 143
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 82-87 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reaction of 1-Methyl-3.4-dihydroisoquinoline with Aryl IsocyanatesDepending upon the reaction conditions, treatment of 1-methyl-3.4-dihydroisoquinoline (4) with aryl isocyanates produces several structurally different products: 2-Arylcarbamoyl-1-methylene-1.2.3.4-tetrahydroisoquinolines (6), 1-(arylcarbamoyl-methylene)-1.2.3.4-tetrahydroisoquinolines (8) and 1-[bis(arylcarbamoyl)methylene]-1.2.3.4-tetrahydroisoquinolines (9). The reaction mechanism is discussed.
    Notes: Bei der Einwirkung von Arylisocyanaten auf 1-Methyl-3.4-dihydro-isochinolin (4) entstehen in Abhängigkeit von den Reaktionsbedingungen strukturell verschiedene Produkte: 1-Methylen-2-arylcarbamoyl-1.2.3.4-tetrahydro-isochinoline (6), 1-Arylcarbamoylmethylen-1.2.3.4-tetrahydro-isochinoline (8) und 1-[Bis-arylcarbamoyl-methylen]-1.2.3.4-tetrahydro-isochinoline (9). Der Mechanismus der Reaktionen wird diskutiert.
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  • 144
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 67-81 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Crystal and Molecular Structure of Pentacarbonyl[dimethylamino(ethoxy)carbene]-chromium(0)Pentacarbonyl[dimethylamino(ethoxy)carbene]chromium(0) (1) crystallizes in space group P&1macr; with a = 11.84 ± 0.01, b = 9.05 ± 0.01, c = 6.49 ± 0.008 Å, α = 95.73 ± 0.08°, β = 105.21 ± 0.08°, γ = 89.84 ± 0.08°, Z = 2. The structure has been solved by the heavy atom method. Least squares refinement led to an agreement factor of R = 0.054 for 2329 independent nonzero observations. The metal atom is approximately octahedrally coordinated by five carbonyl groups and the carbene moiety. All atoms of the carbene ligand are approximately coplanar; this plane is nearly vertical to the plane defined by the equatorial carbonyl groups. The π-character is higher for the carbene carbon-nitrogen bond (1.328 ± 0.005 Å) than for the Ccarbene-oxygen linkage (1.346 ± 0.005 Å). The distance Ccarbene-chromium is 2.133 ± 0.004 Å; the axial Cr-CCO bond is considerably shortened (1.847 ± 0.005 Å) with respect to the distances found for the equatorial Cr-CCO bonds (average: 1.89 Å).
    Notes: Pentacarbonyl-[dimethylamino(äthoxy)carben]-chrom(0) (1) kristallisiert in der Raumgruppe P&1macr; mit a = 11.84 ± 0.01, b = 9.05 ± 0.01, c = 6.49 ± 0.008 Å, α = 95.73 ± 0.08°, β = 105.21 ± 0.08°, γ = 89.84 ± 0.08°, Z = 2. Die Struktur wurde nach der Schweratom-Methode ermittelt und nach der Methode der kleinsten Quadrate verfeinert. Der Übereinstimmungsfaktor beträgt für die 2329 unabhängigen, von Null verschiedenen Strukturfaktoren R = 0.054. Das Metallatom ist annähernd oktaedrisch von fünf Carbonylgruppen und dem Carbenrest umgeben. Alle Atome des Carbenliganden liegen annähernd in einer Ebene, die nahezu senkrecht auf der Ebene der äquatorialen Carbonylgruppen steht. Die Bindung des Carbenkohlenstoffatoms zum Stickstoffatom zeigt mit 1.328 ± 0.005 Å einen stärkeren π-Bindungsanteil als die Carbenkohlenstoff-Sauerstoff-Bindung (1.346 ± 0.005 Å). Der Abstand CCarben-Chrom beträgt 2.133 ± 0.004 Å, die axiale Cr-CCO-Bindung (1.847 ± 0.005 Å) ist gegenüber den Abständen der äquatorialen Cr-CCO-Bindungen (Mittelwert: 1.89 Å) wesentlich verkürzt.
    Additional Material: 4 Ill.
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  • 145
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 108-114 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses with Heterocyclic Amines, IX. Condensed Isoquinolines, IX. Syntheses of Pyrimido[2.1-a]isoquinolines2-Oxo-2H-pyrimido[2.1-a]isoquinolines 3 are formed by treatment of 1-aminoisoquinoline (1) with α,β-unsaturated carboxylic esters. The 4-phenyl derivative 3a is oxidized by potassium permanganate to 2-(o-carboxyphenyl)-4-oxo-6-phenyl-3.4-dihydropyrimidine (8). The reaction of acetoacetic ester with 1 affords the methyl derivative 5b of the isomeric 4-oxo-4H-pyrimido[2.1-a]isoquinolines. The dihydro derivative 6, which is prepared from 1 and acrylic ester, is cleaved by hydrogenation to give N-(2-carbamoylethyl)-1.2.3.4-tetrahydroisoquinoline (7). Malonic ester condenses with 1 to give 2.4-dioxo-3.4-dihydro-2H-pyrimido[2.1-a]isoquinoline (10), and 1-chloroisoquinoline reacts with anthranilic acid to form a benzo derivative 11 of pyrimido-isoquinoline, which is oxidized with potassium permanganate to the 2-(o-carboxyphenyl)-4-quinazolone (12).
    Notes: Bei der Umsetzung von 1-Amino-isochinolin (1) mit α.β-ungesättigten Carbonsäureestern entstehen 2-Oxo-2H-pyrimido[2.1-a]isochinoline 3. Das 4-Phenyl-Derivat 3a wird mit Kaliumpermanganat zum 4-Oxo-6-phenyl-2-[o-carboxy-phenyl]-3.4-dihydro-pyrimidin (8) oxydiert. Acetessigester liefert mit 1 das Methyl-Derivat 5b des isomeren 4-Oxo-4H-pyrimido[2.1-a]isochinolins. Das aus 1 und Acrylsäureester bereitete Dihydro-Derivat 6 wird hydrierend gespalten, wobei N-[2-Carbamoyl-äthyl]-1.2.3.4-tetrahydro-isochinolin (7) entsteht. Malonsäureester kondensiert mit 1 zum 2.4-Dioxo-3.4-dihydro-2H-pyrimido[2.1-a]isochinolin (10) und 1-Chlor-isochinolin liefert mit Anthranilsäure ein Benzo-Derivat 11 der Pyrimido-isochinoline, das mit Kaliumpermanganat zum 2-[o-Carboxy-phenyl]-chinazolon-(4) (12) oxydiert wird.
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  • 146
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    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of Glucuronides in the Flavonoid-Series, IV. Synthesis of Chrysin-7-β-D-glucopyranuronide, -7-β-D-neohesperidoside and -7-β-D-rutinosideCoupling of chrysin with methyl(tri-O-acetyl-α-D-glucopyranosyl bromide)uronate, followed by total acetylation and subsequent removal of the protecting groups yielded chrysin-7-β-D-glucopyranuronide (2). Chrysin-7-β-D-neohesperidoside (5), starting material to get chrysin, was prepared by dehydrogenation of 5.7-dihydroxyflavanone-7-β-D-neohesperidoside heptaacetate with iodine and potassium acetate and subsequent deacetylation. Condensation of chrysin with α-acetobromorutinose, followed by deacetylation of the product resulted in the formation of chrysin-7-β-D-rutinoside (7).
    Notes: Durch Kupplung von Chrysin mit α-Acetobromglucuronsäure-methylester und Verseifen des dargestellten Vollacetats wurde 5.7-Dihydroxy-flavon-7-β-D-glucopyranosiduronsäure (Chrysin-7-β-D-glucopyranuronid) (2) synthetisiert. Chrysin-7-β-D-neohesperidosid (5), die unmittelbare Ausgangsverbindung für die Chrysinherstellung, wurde durch Dehydrierung von 5.7-Dihydroxy-flavanon-7-β-D-neohesperidosid-heptaacetat mit Jod und Kaliumacetat und anschließende Entacetylierung dargestellt. Glykosidierung von Chrysin mit α-Acetobromrutinose und anschließende Verseifung des Teilacetats ergab Chrysin-7-β-D-rutinosid (7).
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  • 147
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 301-311 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Transition Metal Complexes of Cyclic π-Ligands, III. Crystal and Molecular Structure of Tricarbonyl(N-methylpyrrole)chromium(0)Tricarbonyl(N-methylpyrrole)chromium(0) (1) crystallizes in space group P 21/c with a = 7.797 ± 0.008, b = 11.31 ± 0.01, c = 11.90 ± 0.01 Å, β = 124.96 ± 0.08°, Z = 4. The structure of the compo9und has been solved by three-dimensional single crystal X-ray diffraction analysis (R = 0.0529 for 1501 independent nonzero observations). The structure of the molecule is typically that of a tricarbonyl(arene)metal-complex. The three Cr-CCO-bonds are approximately mutually orthogonal. On the side opposite to the carbonyl groups the pyrrole ligand is bonded to the metal with the ring plane nearly parallel to the plane formed by the carbon atoms of the carbonyl groups. The five atoms of the ring are coplanar to within 0.006 Å. In contrast ot the planar free N-methylpyrrole the methyl group is bent out of the ring plane by 8.9° in the direction opposite to the chromium atom in the complex. The bond distances in the ligand are not significantly longer than in uncomplexed pyrrole. This may be taken as indicative of an only weak interaction between the ligand and the metal atom.
    Notes: Tricarbonyl(N-methyl-pyrrol)chrom(0) (1) kristallisiert in der Raumgruppe P 21/c mit a = 7.797 ± 0.008, b = 11.31 ± 0.01, c = 11.90 ± 0.01 Å, β = 124.96 ± 0.08°, Z = 4. Die Struktur der Verbindung wurde mit Hilfe einer dreidimensionalen Einkristall-Röntgenbeugungsanalyse gelöst (R = 0.0529 für 1501 unabhängige, von Null verschiedene Meßwerte). Das Molekül besitzt den für Tricarbonyl(aromat)metall-Komplexe typischen Bau. Die drei Cr-CCO-Bindungen bilden nahezu rechte Winkel miteinander. Annähernd parallel zu der durch die Kohlenstoffatome der Carbonylgruppen gebildeten Ebene liegt auf der anderen Seite des Chromatoms der Pyrrolring. Die fünf Atome des Rings liegen innerhalb von 0.006 Å in einer Ebene. Anders als im freien N-Methyl-pyrrol, das eben gebaut ist, ist im Komplexe die Methylgruppe um 8.9° aus der Ringebene heraus vom Chrom weg abgewinkelt. Die Bindungsabstände im Ring sind gegenüber den Abständen im unkomplexierten Pyrrol nicht signifikant aufgeweitet. Dies spricht für eine nur schwache Wechselwirkung zwischen dem Liganden und dem Metallatom.
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    Berichte der deutschen chemischen Gesellschaft 105 (1972) 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 149
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 337-352 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Cyclobutenediones, XXV. On the Treatment of 2-Hydroxy-1-phenyl-1-cyclobuten-3.4-dione with Aromatic Diamines2-Hydroxy-1-phenyl-1-cyclobuten-3.4-dione (PCB-OH, 1) reacts under ring-opening with o-phenylenediamine to form 3-hydroxy-2-phenyl-1 H-pyrrolo[1.2-a]benzimidazol-1-one (2), its functional groups are proved by chemical reactions. On the alkaline and the acid hydrolysis of 2 2-(phenylacetyl)benzimidazole (8) is received. PCB-OH (1) changes with 1.8. diaminonaphthaline into 3-hydroxy-2-phenyl-1 H-pyrrolo[1.2-a]perimidin-1-one (15). There is no more ring-opening with 2.2'-diaminobiphenyl, the varied conditions afford the cyclobutenediylium-diolate 18. The behaviour of N-monosubstituted o-phenylenediamines is different against PCB-OH (1) - under preservation of the cyclobutene system -N-acetyl-o-phenylenediamine first condenses intramolecular and reacts with 1 to form the ammonium salt 21, N-methyl-respectively N-phenyl-o-phenylenediamine react with 1 to form the spiro-[benzimidazolium-2.1'-cyclobutene]olates 22 and 23.
    Notes: 2-Hydroxy-1-phenyl-cyclobuten-(1)-dion-(3.4) (PCB-OH, 1) reagiert mit o-Phenylendiamin unter Ringöffnung zum 3-Hydroxy-2-phenyl-1 H-pyrrolo[1.2-a]benzimidazol-on-(1) (2), dessen funktionelle Gruppen durch chemische Reaktionen nachgewiesen werden. Bei der alkalischen und der sauren Hydrolyse von 2 wird das 2-Phenylacetyl-benzimidazol (8) erhalten. PCB-OH (1) setzt sich mit 1.8-Diamino-naphthalin zum 3-Hydroxy-2-phenyl-1 H-pyrrolo-[1.2-a]perimidin-on-(1) (15) um. Mit 2.2'-Diamino-biphenyl ist keine Ringöffnung mehr möglich, unter veränderten Reaktionsbedingungen entsteht das Cyclobutendiylium-diolat 18. N-Monosubstituierte o-Phenylendiamine verhalten sich gegenüber PCB-OH (1) - unter Erhaltung des Vierrings - unterschiedlich: N-Acetyl-o-phenylendiamin kondensiert zunächst intramolekular und bildet mit 1 das Ammoniumsalz 21, N-Methyl- bzw. N-Phenyl-o-phenylendiamin ergeben mit 1 die Spiro[benzimidazolium-2.1'-cyclobuten]-olate 22 und 23-
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 358-361 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 151
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 363-367 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Organic Peroxides, XIII. On the Mechanism of the Hunsdiecker ReactionIn the Hunsdiecker reactions of polycyclic bridgehead carboxylic acids in CCl4 alkyl chlorides are formed besides alkyl bromides. When these reactions are conducted under standardized conditions a linear relation is observed between the relative yields RBr/RCl and the known competition constants r for halogen transfer from BrCCl3 and CCl4 to the corresponding free radicals. Free radicals are therefore exclusively responsible for the products in these Hunsdiecker reactions.
    Notes: In den Hunsdiecker-Reaktionen polycyclischer Brückenkopfcarbonsäuren in CCl4 entstehen neben Alkylbromiden auch Alkylchloride. Arbeitet man unter standardisierten Bedingungen, so steht das Ausbeuteverhältnis RBr/RCl in linearer Beziehung zu den Konkurrenzkonstanten r der Halogenübertragung von BrCCl3 und CCl4 auf die entsprechenden Radikale. Dies zeigt, daß die Hunsdiecker-Reaktionen dieser Carbonsäuren ausschließlich über freie Radikale ablaufen.
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 377-387 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Studies on Anthraquinones and their Reduction Products, IV. Studies on the Reaction of Anthrahydroquinones with FormaldehydeMeasurements by direct current polarography showed, that substituted anthrahydroquinones can react with formaldehyde to 10-hydroxy-1-0(hydroxymethyl)-9-anthrones in a reversible reaction. Some of these instable compounds have been isolated and their structures have been determined.
    Notes: Gleichstrompolarographische Messungen zeigten, daß substituierte Anthrahydrochinone mit Formaldehyd in wäßrigem Äthanol im pH-Bereich 7-14 in einer reversiblen Gleichgewichtsreaktion zu 10-Hydroxy-10-hydroxymethyl-anthronen-(9) reagieren können In einzelnen Fällen konnten diese sehr labilen Verbindungen isoliert und ihre Struktur bestimmt werden.
    Additional Material: 2 Ill.
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  • 153
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Derivatives of Methylenedioxybenzene, 35. A Novel Synthesis of 3.6-Dihydroxy-2-ethyl-1.4-benzoquinone, Embelin, Vilangin, Rapanone, Dihydromaesaquinone, Bhogatin, Spinulosin and OosporeinThe title compounds are prepared in a new synthesis using 1-alkyl- or 1.4-dialkyl-5.6-dimethoxy-2.3-methylenedioxybenzenes 1 as starting materials.
    Notes: Die Titelverbindungen werden auf einem neuen Weg unter Verwendung von 1-Alkyl- bzw. 1.4-Dialkyl-5.6-dimethoxy-2.3-methylendioxy-benzolen 1 hergestellt.
    Additional Material: 2 Tab.
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  • 154
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Studies in the Synthesis of the Antibiotics Gliotoxin, Sporidesmin, Aranotin, and Chaetocin, III. Introduction of Alkyl Groups and Sulfur Functions into the -3 and 6-Positions of 2.5-Dioxo-piperazines by Electrophilic SubstitutionsL-Prolyl-L-proline anhydride (4a) has been metalated to form the monoanion 5, the reprotonation of which leads back to 4a without loss of optical activity. Alkylation of 5 produces optically active 3-ethyl-L-prolyl-L-proline anhydride (6). Further metalation and alkylation of 6 leads to inactive 3.6-diethyl-prolyl-proline anhydride (7). The anion 5 reacts with sulfur and ethyl bromide to form optically active 3-ethylthio-L-prolyl-L-proline anhydride (11a). The (inactive) trans-3.6-bis(ethylthio)-prolyl-proline anhydride (13) has been obtained from the mercaptide 10 by metalation followed by reaction with sulfur and subsequent alkylation of the intermediate 3.6-dimercaptide 12.
    Notes: L-Prolyl-L-prolinanhydrid (4a) wurde zum Monoanion 5 metalliert, dessen Reprotonierung unter nur geringem Verlust an optischer Drehung wieder 4a ergab. Auch die Alkylierung des Anions 5 lieferte optisch aktives -3Äthyl-L-prolyl-L-prolinanhydrid (6). Weitere Metallierung und Alkylierung von 6 führte zum inaktiven trans-3.6-Diäthyl-prolyl-prolinanhydrid (7). Das Anion 5 reagierte mit Schwefel und Äthylbromid zum optisch aktiven -3Äthylmercapto-L-prolyl-L-prolinanhydrid (11a). Inaktives trans-3.6-Bis-äthylmercapto-prolyl-prolinanhydrid (13) entstand durch erneute Metallierung des Mercaptids 10, Umsetzung mit Schwefel zum Dimercaptid 12 und dessen Dialkylierung.
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  • 155
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 658-672 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Microbiological Hydroxylation of 5α.6α-Epoxy-3β-hydroxy-5α-pregnane-20-ones with further TransformationsThe fungus Curvularia lunata transforms in prolongated incubation time 5α.6α; 16α.17α-diepoxy-3β-hydroxy-5α-pregnane-20-one (1) to the 5β-H-6-ketone 3 and 4 through the primarily formed 11β-hydroxy-structure 2. 5α.6α-Epoxy-3β-hydroxy-5α-pregnane-20-one (6) is oxidized to 14α- or 17α-hydroxy-11-ketones (8-10, 12). During this reaction a change of the substitution pattern of the rings A and B is sometimes observed. The corresponding 16α-methyl-substituted substrate 14 is transformed through some intermediates to the stable product 5α.6α-epoxy-3β.15β-dihydroxy-16α-methyl-5α-pregnane-11.20-dione (18). The constitutions of the isolated compounds were elucidated by n.m.r., i.r., mass spectroscopic, and c.d. investigations.
    Notes: Der Pilz Curvularia lunata wandelt 3β-Hydroxy-5α.6α; 16α.17α-diepoxy-5α-pregnanon-(20) (1) bei verlängerter Inkubationszeit über die primär entstehende 11β-Hydroxystruktur 2 in die 5β-H-6-Ketone 3 und 4 um. 3β-Hydroxy-5α.6α-epoxy-5α-pregnanon-(20) (6) wird zu 14α-oder 17α-Hydroxy-11-ketonen (8-10, 12) oxydiert, wobei gleichzeitig noch eine Änderung des Substitutionsmusters am A- und B-Ring eintreten kann, während die entsprechende 16α-Methylverbindung 14 über verschiedene Zwischenstufen zum stabilen Endprodukt 3β.15β-Di-hydroxy-5α.6α-epoxy-16α-methyl-5α-pregnandion-(11.20) (18) transformiert wird. Die Konstitutionen der isolierten Verbindungen wurden durch NMR-, IR-, MS- und CD-Untersuchungen gesichert.
    Additional Material: 1 Tab.
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  • 156
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    Berichte der deutschen chemischen Gesellschaft 105 (1972) 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 157
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 753-756 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Heterocyclic β-Enaminoesters, IX The Synthesis of Furo[2.3-e]-1.4-diazepines and their N.M.R. Analysis by Means of the Tris(dipivalo-methanato)europium Complex2-Amino-3-ethoxycarbonyl-4.5-dihydrofurans 1a-d react with ethylene diamine under substitution of the 2-amino group to yield furo[2.3-e]-1.4-diazepin-5-ones 2a-d. With the aid of tris(dipivalo-methanato)europium complex, Eu(DPM)3, the n.m.r. spectra can be considered as such of the 1st order.
    Notes: Die 2-Amino-3-äthoxycarbonyl-4.5-dihydro-furane 1a-d reagieren mit Äthylendiamin unter Substitution der 2-Aminogruppe zu Furo[2.3-e]-1.4-diazepinonen-(5) 2a-d. Mit dem Tris-(dipivalo-methanato)-europium-Komplex, Eu(DPM)3, lassen sich die NMR-Spektren als solche 1. Ordnung interpretieren.
    Additional Material: 2 Tab.
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  • 158
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 673-685 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of 2.-3(Carboxymethylene)- and 2.-3(2-Hydroxyethylidene)-2.3-dideoxy-D-mannose  -  Monosaccharides with a Cyclopropane RingThe anhydro derivative 1 yielded the cyclopropane carboxylic ester 2 in a PO-activated olefination reaction. Under mild conditions 2 could be hydrolised to the free carboxylic acid 5. By reduction the cyclopropyl carbinol 13 and the cyclopropane carbaldehyde 21 were formed. The latter could be rearranged to the cyclobutene derivative 25. Attempts to synthesize a cyclopropanol were unsuccessful.
    Notes: Durch PO-aktivierte Olefinierung entstand aus der Anhydro-Verbindung 1 der Cyclopropancarbonsäureester 2, der unter milden Bedingungen zur freien Carbonsäure 5 hydrolysiert werden konnte. Reduktion lieferte das Cyclopropylcarbinol 13 und den Cyclopropan-carbaldehyd 21, der zum Cyclobutenderivat 25 umgelagert wurde. Die Synthese eines Cyclopropanols gelang nicht.
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  • 159
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    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Conformational Analysis, I. Dependency of syn-1.3-Diaxial Interaction on the Kind of Substituents and on the Solvent Studies on the Conformational Equilibria of D-Idopyranose DerivativesThe syn-1.3-diaxial interaction of two OAc-groups is very small compared to that of two OMe-groups. syn-1.3-Diaxial interaction of two OMe-groups and anomeric effect are maximal in unpolar solvents. In chloroform hydrogen bridge linkages with the anomeric OMe-group are formed which weaken the anomeric effect and in the α-series the syn-1.3-diaxial interaction. The site of conformational equilibria which is determined by the variable influence of syn-1.3-diaxial interaction, anomeric effect, and solvent is discussed for differently substituted D-idopyranose derivatives of the α- and β-series.
    Notes: Die syn-1.3-diaxiale Wechselwirkung zweier OAc-Gruppen ist verschwindend klein gegenüber der von zwei OCH3-Gruppen. In unpolaren Lösungsmitteln sind syn-1.3-diaxiale Wechselwirkung zweier OCH3-Gruppen und der anomere Effekt am größten. In Chloroform treten Wasserstoffbrückenbeziehungen zur anomeren OCH3-Gruppe auf, die den anomeren Effekt und in der α-Reihe die 1.3-diaxiale Wechselwirkung schwächen. Das die Lage der Konformeren-Gleichgewichte bestimmende Wechselspiel von syn-1.3-diaxialer Wechselwirkung, anomerem Effekt und Einfluß des Lösungsmittels wird an verschieden substituierten D-Idopyranose-Derivaten der α- und β-Reihe diskutiert.
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  • 160
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 735-739 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Compounds with Urotropin Structure, IL. Preparation and Fragmentation of 5.7-Dibromoadamantane-2-carboxylic AcidA new, productive synthesis of adamantane-2-carboxylic acid (5) starting with adamantanone (1) is described. Catalytic bromination of the acid in liquid bromine leads to 5.7-dibromo-adamatane-2-carboxylic acid (6). The proof of the substitution in the -5 and 7-positions is successfully furnished by alkaline fragmentation of 6 to 3-methylene-7-oxobicyclo[3.3.1]-nonane-9-carboxylic acid (7) and subsequent ozonolysis to 3.7-dioxobicyclo[3.3.1]nonane-9-carboxylic acid (8). The fragmentation product 7 serves as starting material for ring closures to 1.3.6-trisubstituted adamantane derivatives (11-13).
    Notes: Es wird eine neue, ergiebige Synthese der Adamantan-carbonsäure-(2) (5), ausgehend von Adamantanon (1), beschrieben. Durch katalytische Bromierung der Säure in flüssigem Brom erhält man die 5.7-Dibrom-adamantan-carbonsäure-(2) (6). Der Beweis für die Substitution in der -5 und 7-Stellung gelingt durch alkalische Fragmentierung von 6 zur 7-Oxo-3-methylen-bicyclo[3.3.1]nonan-carbonsäure-(9) (7) und anschließende Ozonolyse zur 3.7-Dioxo-bicyclo-[3.3.1]nonan-carbonsäure-(9) (8). Das Fragmentierungsprodukt 7 dient als Ausgangssubstanz für Ringschlüsse zu 1.3.6-trisubstituierten Adamantanderivaten (11-13).
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  • 161
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 757-769 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 1.2.4-Benzothia(IV)diazines and 1.2.5-Benzothia(IV)diazepines, Ring Enlargement of Some Chloromethyl-1.2.4-benzothia(IV)diazine 1-oxidesDiarylsulfoxides 4 react with hydrazoic acid in the presence of sulfuric acid to form 1.2.4-benzothia(IV)diazine 1-oxides 7. On treatment of 3-chloromethyl-1-aryl-1.2.4-benzothia(IV)-diazine 1-oxides 7a-d with sodium hydroxide a novel rearrangement occurs affording 1-aryl-4-oxo-4.5-dihydro-3H-1.2.5-benzothia(IV)diazepine 1-oxides 9. Reaction of 7a-d with primary amines in alcoholic solution proceeds without rearrangement.
    Notes: Diarylsulfoxide 4 reagieren mit Stickstoffwasserstoffsäure in Gegenwart von Schwefelsäure zu 1.2.4-Benzothia(IV)diazin-1-oxiden 7. 3-Chlormethyl-1-aryl-1.2.4-benzothia(IV)diazin-1-oxide 7a-d erfahren unter dem Einfluß von Hydroxidionen eine Ringerweiterung zu 1-Aryl-4-oxo-4.5-dihydro-3H-1.2.5-benzothia(IV)diazepin-1-oxiden 9, einem neuen heterocyclischen Ringsystem. Reaktion von 7a-d mit primären Aminen in alkoholischer Lösung führt zu normaler Substitution.
    Additional Material: 3 Tab.
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  • 162
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 1388-1391 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 1.3-Migration Tendency of Silyl Groups in SilyltriazenesSilyl groups in silyl-1.3-dimethyltriazenes MeN = N-NMe(SiR3) migrate between positions 1 and 3 of the triazene chain. From the rate of the 1.3-migration of the silyl groups, measured by 1H n.m.r. spectroscopy, it follows that the migration tendency of the silyl groups SiR3 increases in the following order of the ligands bound to silicon: R = Et 〈 Me 〈 OMe 〈 Cl.
    Notes: Silygruppen in Silyl-1.3-dimethyl-triazenen MeN = N-NMe(SiR3) fluktuieren zwischen den Positionen 1 und 3 der Triazenkette. Aus der Geschwindigkeit der 1.3-Silylgruppenwanderung, die sich 1H-NMR-spektroskopisch bestimmen läßt, folgt zunehmende Wandertendenz der Silylgruppen SiR3 in der Reihenfolge der Liganden R = Ät 〈 Me 〈 OMe 〈 Cl.
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  • 163
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 1439-1445 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Linear and Cyclic ChlorophosphazenesThe preparation of linear chlorophosphazenes (2-5) with siliconorganic substitutents is described. On the basis of 1H- and 31P n.m.r. spectra their structures are discussed. The siliconorganic derivatives react with phosphorus pentachloride to give covalent polychlorophosphazenes. SPCl2NPCl2NPCl2NCH3Si(CH3)3 (3) is decomposed under evolution of (CH3)3SiCl and formation of a new cyclic phosphazene (6). Analytical data, i.r. and mass spectra support the structures of the new compounds.
    Notes: Über die Darstellung linearer Chlorphosphazene (2-5) mit siliciumorganischen Substituenten wird berichtet. Aufgrund von 1H- und 31P-NMR-Spektren werden ihre Strukturen diskutiert. Die siliciumorganischen Derivate reagieren mit Phosphorpentachlorid zu kovalenten Polychlorphosphazenen. SPCl2NPCl2NPCl2NCH3Si(CH3)3 (3) kann thermisch unter (CH3)3SiCl-Abspaltung zu einem neuen cyclischen Phosphazen (6) abgebaut werden. Analysen, IR- und Massenspektren stützen die Strukturen der neuen Verbindungen.
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  • 164
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 1465-1470 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Vinyl Cations, V. Kinetics and Solvolysis of Nonafluorobutanesulfonates („Nonaflates“)The preparation and the properties of nonafluorobutanesulfonates (“nonaflates”) 1a-6a are described. The solvolysis of the cyclic vinyl nonaflates 1a-3a, like that of the already described trifluoromethanesulfonates, leads exclusively to the corresponding ketones. The nonafluorobutanesulfonates solvolyse 1.5-2 times faster than the trifluoromethanesulfonates. Therefore the nonafluorobutanesulfonate anion is the best leaving group in solvolysis reactions hitherto reported.
    Notes: Die Darstellung und die Eigenschaften der Nonafluorbutansulfonate (“Nonaflate”) 1a-6a werden beschrieben. Die Solvolyse der cyclischen Vinyl-nonaflate 1a-3a führt wie bei den entsprechenden Trifluormethansulfonaten nur zu den Ketonen, erfolgt aber 1.5-2 mal schneller als bei den Trifluormethansulfonaten. Das Nonafluorbutansulfonat-Anion stellt damit die zur Zeit beste Abgangsgruppe bei Solvolysereaktionen dar.
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  • 165
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 1510-1514 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Reaction of N.N′-Bis(trichlorophosphoranylidene)sulfamideSO2(NPCl3)2 reacts with silylamines (CH3)3SiNHR (R = C2H5, C3H7, C4H9) in a molar ratio of 1 : 2 to give 1, 2 and 3, with (CH3)3SiNHCH3 in a molar ratio of 1 : 1 to give the cyclic compound 41,2). From SO2(NPCl3)2 and disilylamines the compounds 5 and 6 can be obtained. The reaction of SO2[NPCl2N(C2H5)2]22) with [(CH3)3Si]2NCH3yields the heterocyclic compound 7. - The i.r., mass, 1H and 31P n.m.r. spectra of these compounds are reported.
    Notes: SO2(NPCl3)2 reagiert mit Silylaminen (CH3)3SiNHR (R = C2H5, C3H7, C4H9) im Molverhältnis 1 : 2 zu 1, 2 und 3, mit (CH3)3SiNHCH3 im Molverhältnis 1 : 1 zu der cyclischen Verbindung 41,2). Aus SO2(NPCl3)2 und Disilyaminen konnten die Verbindungen 5 und 6 gewonnen werden. Schließlich ist aus SO2[NPCl2N(C2H5)2]22) und [(CH3)3Si]2NCH3 die cyclische Verbindung 7 zugänglich. - Die IR-, Massen- und 1H- bzw. 31P-NMR-Spektren dieser Verbindungen werden mitgeteilt.
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  • 166
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 1553-1561 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Chemistry of Carbinol Bases of 3-Azabicyclo[3.2.2]nonanesMercuric acetate oxidation of some tertiary 3-azabicyclo[3.2.2]nonanes (1a-c) representing a bridged bicyclic 6/7-ring system has been investigated. The results are compared with the different ones obtained from the oxidation of bridged 6/6-ring systems.
    Notes: N-Alkylierte 3-Aza-bicyclo[3.2.2]nonane (1a-c) als Vertreter verbrückter, bicyclischer 6/7-Ringsysteme werden mit Quecksilber(II)-acetat dehydriert. Die im Vergleich zu 6/6-Ringsystemen unterschiedlichen Ergebnisse werden diskutiert.
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  • 167
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 1586-1594 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Derivatives of Methylendioxybenzene, 36Syntheses of Substituted 4.5-Methylenedioxy-1.2-benzoquinonesThe preparation of 3-carbonyl-, methoxycarbonyl- and carbonamide-substituted 4.5-methylenedioxy-1.2-benzoquinones by treating correspondingly substituted 1.2-dimethoxy-4.5-methylenedioxy benzene derivatives with diluted nitric acid is described.
    Notes: Die Darstellung von in 3-Stellung durch Carbonyl-, Methoxycarbonyl- und Carbonamid-Funktionen substituierten 4.5-Methylendioxy-benzochinonen-(1.2), ausgehend von den entsprechend substituierten Dimethoxy-methylendioxy-benzol-Abkömmlingen und verd. Salpetersäure, wird beschrieben.
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 1621-1633 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Hydroxyalkylation of N.N-Dialkylcarboxamides with EpoxidesThe hydroxyalkylation of α-carbanions from N.N-dialkylcarboxamides with epoxides is demonstrated with eleven examples (1, 5, 12, 16, 18, 21, 25, 28, 32, 37, 41). Satisfactory yields are obtained with ethylene oxide and with mono- or unsymmetrically disubstituted oxiranes. Some γ-hydroxy amides were reduced with lithium aluminium hydride and the products subjected to Cope degradation.
    Notes: An elf Beispielen (1, 5, 12, 16, 18, 21, 25, 28, 32, 37, 41) wird die Hydroxyalkylierung von α-Carbanionen aus Carbonsäure-dialkylamiden mit Epoxiden in flüssigem Ammoniak beschrieben. Befriedigende Ausbeuten werden mit Äthylenoxid sowie mit mono- oder unsymmetrisch disubstituierten Oxiranen erhalten. Einige γ-Hydroxy-amide wurden mit Lithiumalanat reduziert und die Produkte nach Cope abgebaut.
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  • 169
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 975-981 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: N.N-Disubstituted 2-Aminocyclobutanones from 2-Hydroxycyclobutanones and Secondary AminesN.N-Disubstituted 2-aminocyclobutanones (7) are readily formed under mild conditions by reaction of 2-aminocyclobutanones (7) are readily formed under mild conditions by reaction of 2-hydroxycyclobutanone (6) with secondary amines in solution at room temperature. Optimum yields are obtained when 6 - prepared by hydrolysis of 1.2-bis(trimethylsiloxy)cyclobut-1-ene (8) - reacts in situ. By this method derivatives of 7 as well as higher homologous 2-aminocycloalkanones are also easily prepared.
    Notes: 2-Hydroxy-cyclobutanon (6) reagiert bei 20° in Lösung glatt mit sekundären Aminen zu den N.N-disubstituierten 2-Amino-cyclobutanonen (7). Optimale Ausbeuten an 7 lassen sich erzielen, wenn 6 in situ - dargestellt durch Hydrolyse des 1.2-Bis-trimethylsiloxy-cyclo-butens-(1) (8) - umgesetzt wird. Auf diese Weise sind auch Derivate von 7 sowie höherhomologe 2-Amino-cycloalkanone leicht erhältlich.
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 1004-1018 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Selective Catalytic Oxidations, XXX Catalytic Oxidation of Bicyclo[2.2.1]heptanediolsThe 13 isomeric Bicyclo[2.2.1]heptanediols were oxidized by oxygen on the platinum contact in aqueous solutions, and oxidation products and relative oxidation rates were studied. Oxidation of endo-hydroxyl groups is generally preferred to exo-hydroxyl groups, and again oxidation of the latter is preferred to C-7-hydroxyl groups. The observed order of decreasing reactivity is: 13, 1, 7, 25, 4, 18, 12, 19, 6, 10, 16, 26 and 23, and can essentially be related to steric hindrance of the dehydration process. N.m.r. spectra of the 13 diols are discussed.
    Notes: Die 13 isomeren Bicyclo[2.2.1]heptandiole wurden mit Sauerstoff am Platinkontakt in wäßriger Lösung oxydiert und Oxydationsprodukte und Oxydationsgeschwindigkeiten vergleichend untersucht. endo-OH-Gruppen werden allgemein vor exo-OH-Gruppen und diese vor C-7-OH-Gruppen oxydiert. Die beobachtete Reihenfolge abnehmender Reaktivität 13, 1, 7, 25, 4, 18, 12, 19, 6, 10, 16, 26 und 23 läßt sich im wesentlichen auf eine sterische Behinderung des Dehydrierungsvorganges zurückführen. Die NMR-Spektren der 13 Diole werden diskutiert.
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  • 171
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 1032-1043 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Directed Synthesis of Sulfinato-O and -S Complexes of some Transition Metals, IV Linkage Isomerism in Sulfinato Complexes of Iron(II), Cobalt(II) and Nickel(II)Treatment of the sulfinato-O.O' complexes 1a-c with 2.2′-bipyridyl produces the ionic tris complexes 4a-c according to equation (4). The action of acetone results in the elimination of only 1 mole of 2.2′-bipyridyl from 4a-c to yield the linkage-isomeric sulfinato complexes of iron, cobalt, and nickel (3aO-cO and 3aS-cS) according to equation (5). 3aS can also be prepared in pyridine solution by the reaction of 1a or 2a with 2.2′-bipyridyl according to equations (2) and (3). In pyridine at 115° the O-isomers 3aO and 3cO are converted irreversibly into the S-isomers 3aS and 3cS according to equation (6). 4a is transformed via 3aO to the sulfinato-O.O' complex 2a if it is treated with acetone for a longer time. According to this result equation (1) is reversible from 2a via 3aO to 4a for M = Fe. The linkage isomers 3aO-cO and 3aS-cS are characterized on the basis of their i.r., electronic and Mössbauer spectra as well as by magnetochemical investigations.
    Notes: Durch Einwirkung von 2.2′-Bipyridyl auf die Sulfinato-O.O'-Komplexe 1a-c erhält man gemäß Gl. (4) die ionogenen Tris-Komplexe 4a-c. Mit Aceton läßt sich daraus gezielt 1 Mol 2.2′-Bipyridyl abspalten, wodurch entsprechend Gl. (5) die bindungsisomeren Sulfinato-Komplexe des Eisens, Kobalts und Nickels 3aO-cO und 3aS-cS zugänglich sind. 3aS bildet sich auch bei der Umsetzung von 1a oder 2a mit 2.2′-Bipyridyl gemäß Gl. (2) und (3) in Pyridin. Die O-Isomeren 3aO und 3cO werden in Pyridin bei 115° entsprechend Gl. (6) irreversibel in die S-Isomeren 3aS und 3cS übergeführt. Speziell 4a geht bei längerer Einwirkung von Aceton über 3aO in den Sulfinato-O.O'-Komplex 2a über. Gl. (1) läßt sich demnach für M = Fe von 2a über 3aO zu 4a reversibel formulieren. Die Bindungsisomeren 3aO-cO und 3aS-cS werden an Hand ihrer IR-, Elektronen- und Mössbauer-Spektren sowie durch magnetochemische Untersuchungen charakterisiert.
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  • 172
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 1087-1091 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Tab.
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  • 173
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 1097-1110 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Studies on Glycoside Synthesis, IV. Novel Silver Salts in Glycoside SynthesisThe glykosylation of steroid alcohols (e.g. 4, and 9-12, R==OH) with cis-halogenoses in the presence of various silver salts was investigated. In many cases the silver salts of 2-, 3-, and 4-hydroxyalkanoic acids as well as of 1.3- and 1.4-dicarboxylic acids proved to be superior to the commonly used Ag2CO3 or Ag2O. Good yields (5, 7-12) were obtained in cases in which neighbouring group effects within the anion limit the formation of 1-O-acylglycoses in favour of glycoside formation. The reaction takes place most readily in diethyl ether and is well suited for the glycosylation of chemically sensitive alcohols.
    Notes: Bei der Glykosylierung von Steroidalkoholen (u.a. 4 und 9-12, R == OH) mit cis-Halogenosen in Gegenwart verschiedener Silbersalze erwiesen sich die von 2-, 3-und 4-Hydroxy-carbonsäuren sowie von 1.3- und 1.4-Dicarbonsäuren den üblichen Salzen in vielen Fällen als überlegen. Gute Ausbeuten (an 5, 7-12) wurden dann erhalten, wenn im Anion des Silbersalzes durch eine Nachbargruppenbeziehung die Bildung der 1-O-Acyl-glucose zugunsten der Glykosidbidung eingeschränkt ist. Die Reaktion verläuft in Diäthyläther am besten und ist besonders auch zur Glykosylierung von chemisch empfindlichen Alkoholen gut geeignet.
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  • 174
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 1142-1147 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Properties of the Dibenzo[c.h]phenothiazinyl RadicalThe stable free title radical 2 is obtained from 7H-dibenzo[c.h]phenothiazine (1) by dehydrogenation with yellow HgO. For 2 a free radical content of 64% in solution (room temperature) and 6% in the crystalline state has been determined by e.s.r. The complex e.s.r. spectrum of 2-solutions is discussed in connection with Hückel calculations. A 1:1-adduct of 1 and 2 in the crystalline state exhibit a radical content of 72% (referred to 2). 2 and the formerly described dinaphtho[2.3-c : 2′.3′hyphen;h]phenothiazinyl (5) display characteristic u.v. spectra.
    Notes: 7H-Dibenzo[c.h]phenothiazin (1) liefert bei der Dehydrierung mit gelbem HgO das stabile freie Titel-Radikal 2. Der Radikalgehalt (Raumtemperatur) beträgt nach ESR-Messungen in Lösung 64%, im Kristall 6%. Das linienreiche Lösungs-ESR-Spektrum wird im Zusammenhang mit Hückel-Rechnungen diskutiert. Ein 1:1-Addukt von 1 und 2 weist (im Kristall) einen Radikalgehalt von 72% (bezogen auf 2) auf. 2 und das früher beschriebene Dinaphtho-[2.3-c : 2′.3′-h]phenothiazinyl1) (5) zeigen charakteristische UV-Spektren.
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  • 175
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 1174-1183 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Carbonyl Insertion Reactions, I. Reactions of s̰-Alkyl-π-cyclopentadienylmetal Carbonyl Complexes with Cyanid Ionsπ-C5H5Fe(CO)2R and π-C5H5M(CO)3R (R == CH3, C2H5; M == Mo, W) react with KCN in methanol to afford the corresponding cyano(acyl)metallates K[π-C5H5M(CO)n(COR)CN] (1-4). By treatment with an aquous solution of (C6H5)4AsCl this anions yield the (C6H5)4Asπ salts (1a-4a). So for the first time we succeeded to get an insertion reaction of the very low reactiv π-C5H5W(CO)3CH3. Methylation of the metallates yields the corresponding neutral isonitril complexes π-C5H5M(CO)n(CNCH3)(COR) (5-7). Furthermore it is shown that the insertion reaction of π-C5H5Mo(CO)3CH3 with KCN yields stereospecifically the cis-complex K[π-C5H5Mo(CO)2(CN)(COCH3)]. This reaction is followed by an isomerisation which leads to the trans-isomer. - The structures of the newly prepared substances are elucidated by i.r. and 1H n.m.r. spectroscopy.
    Notes: π-C5H5Fe(CO)2R und π-C5H5M(CO)3R (R == CH3, C2H5; M == Mo, W) reagieren mit KCN in Methanol zu den entsprechenden Cyano-s̰-acyl-metallaten K[π-C5H5M(CO)n(COR)CN] (1-4), die mit (C6H5)4AsCl aus wäßriger Lösung fällbar sind (1a-4a). So konnte an dem reaktionsträgen Wolframkomplex π-C5H5W(CO)3CH3 erstmals eine durch eine Base induzierte Acylierung („Insertionsreaktion“) durchgeführt werden. Die Methylierung der Metallate führt zu den neutralen Isonitrilderivaten π-C5H5M(CO)n(CNCH3)(COR) (5-7). Ferner wird nachgewiesen, daß π-C5H5Mo(CO)3CH3 mit KCN in einer stereospezifischen Reaktion primär das cis-Derivat K[π-C5H5Mo(CO)2(CN)(COCH3)] bildet, das sich zum trans-Isomeren umlagert. IR- und 1H-NMR-Spektren der dargestellten Verbindungen sowie ihre Struktur werden diskutiert.
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  • 176
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 1216-1223 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Nitroxides, IX. Preparation of Cyclic Imino-nitroxides and Isotopically Labelled Porphyrexides. E. s. r. Spectroscopic Investigation on the Structure of PorphyrexideThe cyclic imino-nitroxides 4 and 10 and the disubstituted porphyrexide 14 are prepared as model compounds for porphyrexide (1), and their e.s.r. spectra are analysed. The unambigious interpretation of the e.s.r. spectrum of porphyrexide is achieved using the isotopically labelled porphyrexides 15-17.
    Notes: Als Modellsubstanzen für das Porphyrexid (1) werden die cyclischen Imino-nitroxide 4 und 10 sowie das disubstituierte Porphyrexid 14 dargestellt und ihre ESR-Spektren analysiert. Mit Hilfe der isotop-markierten Porphyrexide 15-17 gelingt die eindeutige Interpretation des ESR-Spektrums des Porphyrexids.
    Additional Material: 1 Ill.
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  • 177
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 1683-1693 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Dicyclopropylacetylene - Synthesis, Stereoselective Hydrogenations, and some CycloadditionsDicyclopropylacetylene (9) is prepared in two steps from dicyclopropyl ketone via a Fritsch-Buttenberg-Wiechell rearrangement of 1-chloro-2.2-dicyclopropylethylene (7). Stereo-selective catalytic hydrogenations of 9 with Lindlar catalyst and with lithium aluminium hydride yield cis- and trans-dicyclopropylethylene (12, 14), respectively. The cycloaddition of 9 to fluoro- and chlorosulfonyl isocyanate and of cis-dicyclopropylethylene to chlorosulfonyl isocyanate furnishes high yields of adducts 20, 18 and 21, respectively, without ring opening of the cyclopropyl groups.
    Notes: Dicyclopropylacctylen (9) wird in zwei Stufen aus Dicyclopropylketon über eine Fritsch-Buttenberg-Wiechell-Umlagerung von 1-Chlor-2.2-dicyclopropyl-äthylen (7) dargestellt. Seine katalytische Hydrierung in Gegenwart von Lindlar-Katalysator bzw. Lithiumalanat führt stereoselektiv zu cis- bzw. trans-Dicyclopropyläthylen (12, 14). Die Cycloaddition von 9 an Fluor- bzw. Chlorsulfonylisocyanat und von cis-Dicyclopropyläthylen an Chlorsulfonyl-isocyanat ergibt in hohen Ausbeuten die Cycloaddukte 20 und 18 bzw. 21 mit intakten Cyclopropylgruppen.
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  • 178
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 1718-1725 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Mechanism of the Dakin-West Reaction, III Ring Opening of 4-Acyloxazolin-5-ones by Carboxylic AcidsBy means of 18O-labelled compounds it was shown that in the Dakin-West reaction of N-benzoylalanine the ring opening of the intermediary 4-acyloxazolin-5-one 1a proceeds via attack of the carboxylic acid on the lactone carbonyl group. In addition, the sec. amino acid derivative N-methyl-N-(benzoyl)phenylglycine shows a considerable amount of ring opening via addition of carboxylate at C-2 of the corresponding oxo-oxazolinium intermediate 13.
    Notes: Mit Hilfe 18O-markierter Verbindungen wird gezeigt, daß bei der Dakin-West-Reaktion von N-Benzoyl-alanin die Ringöffnung des intermediär entstehenden 4-Acyl-oxazolinons 1a durch Angriff der Carbonsäure auf die Lacton-Carbonylgruppe erfolgt. Beim sek. Aminosäure-Derivat N-Methyl-N-benzoyl-phenylglycin tritt daneben in beträchtlichem Umfang Ringöffnung durch Anlagerung von Carboxylat an C-2 der entsprechenden Oxo-oxazolinium-Zwischenstufe 13 ein.
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  • 179
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 1749-1754 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Immunological Properties of Two Symmetrical Cystine Peptides with the Sequences A 14-21 and A 15-21 of the Insulin A ChainThe fully protected cystine peptides [Z-Gln-Leu-Glu(OBut)-Asn-Tyr(But)-|Cys-Asn-OBzl]2 (10) and [Z-Tyr(But)-Gln-Leu-Glu(OBut)-Asn-Tyr(But)-|Cys-Asn-OBzl]2 (11), the amino acid sequences of which correspond to sequences A 15-21 and A 14-21 of the insulin A chain, respectively, were prepared by condensation of either a penta (5)- or a heptapeptide (6) derivative via the azide with a bifunctional cystine peptide (9). These were then converted into the corresponding deblocked cystine peptide (12 or 13) by treatment with hydrogen bromide in trifluoracetic acid. The (A 14-21)2 cystine peptide (13) showed immunological activity in the passive cutaneous anaphylaxia test.
    Notes: Die vollständig geschützten Cystinpeptide [Z-Gln-Leu-Glu(OBut)-Asn-Tyr(But)-|Cys-Asn-OBzl]2 (10) bzw. [Z-Tyr(But)-Gln-Leu-Glu(OBut)-|Cys-Asn-OBzl]2 (11), deren Aminosäurefolgen den Sequenzen A 15-21 bzw. A 14-21 der Insulin-A-Kette entsprechen, wurden durch Kondensation eines Pentapeptid-Derivates (5) bzw. eines Hexapeptid-Derivates (8) über das Azid mit dem bifunktionellen Cystinpeptid (9) hergestellt und durch Behandlung mit Bromwasserstoff in Trifluoressigsäure in die schutzgruppenfreien Cystinpeptide 12 bzw. 13 übergeführt. Im Test auf passive cutane Anaphylaxie erwies sich das Cystinpeptid (A 14-21)2 (13) als immunologisch aktiv.
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  • 180
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    Keywords: Chemistry ; Inorganic Chemistry
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    Topics: Chemistry and Pharmacology
    Description / Table of Contents: α-Alkoxy-β-ketosulfones, 2.1. Mitteil.: K. Schank, Liebigs Ann. Chem. 716, 87 (1968). Particulars and Optimal Reaction Conditions with regard to S-Alkylation of Sulfinate Anions by α-Halogen α-Acyl EthersDuring SN reactions with α-halogen ethers sulfinate anions are alkylated both at O and S. The dependence of reaction course on external (solvent, concentration) and internal (substituent and cation effects at the nucleophile; alkylating reagent) factors is investigated with α-halogen α-acyl ethers and is exploited for specific S-alkylation.
    Notes: Sulfinatanionen werden bei SN-Reaktionen mit α-Halogenäthern sowohl O- als auch S-alkyliert. Am Beispiel von α-Halogen-α-acyl-äthern wird die Abhängigkeit der Reaktionsrichtung von externen (Lösungsmittel; Konzentration) und internen (Substituenten- und Kationeneffekte beim Nucleophil; Alkylierungsmittel) Faktoren untersucht und zur gezielten S-Alkylierung ausgewertet.
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  • 181
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 2264-2270 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Orthoamides, XXII. Synthesis and Reactions of O.N-Bis(trimethylsilyl) formamideFormamide reacts with trimethylchlorosilane to give bis(trimethylsilyl) formamide (2). Reaction of 2 with enolisable CH2-active compounds (6-9) results in trimethylsilylethers (13-16) and N-(trimethylsilyl) formamide (20), whereas reaction of 2 with non enolisable CH2-active compounds (10-12) affords aminomethylene compounds (17-19) and hexamethylsiloxane (21).
    Notes: Aus Formamid und Trimethylchlorsilan entsteht Bis-trimethylsilyl-formamid (2). 2 bildet mit enolisierbaren CH2-aktiven Verbindungen (6-9) silylierte Enoläther (13-16) und N-Trimethylsilyl-formamid (20), mit nicht enolisierbaren CH2-aktiven Verbindungen (10-12) Aminomethylen-Verbindungen (17-19) und Hexamethylsiloxan (21).
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  • 182
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 2284-2289 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Influence of Substituents on the Hydrogen Bond in DibenzoylmethanesLinear relationships between the chemical shift of the hydroxylic proton in p- and p.p′-substituted dibenzoylmethanes and the average of the π-electron densities on the oxygen atoms resp. the sum of the substituent constants σp are reported. The H-atom is centrally located between the oxygen atoms.
    Notes: Zwischen der Lage des Wasserstoffbrückensignals im NMR-Spektrum der p- und p.p′-substituierten Dibenzoylmethane und dem Mittelwert der π-Elektronendichten an den Sauerstoffatomen bzw. der Summe der Substituentenkonstanten σp bestehen lineare Beziehungen. Das deutet darauf hin, daß das Proton in der Wasserstoffbrückenbindung sich in der Mitte zwischen den Sauerstoffatomen aufhält.
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  • 183
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 2358-2367 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Total Synthesis of Optically Active Steroids, VIII. Preparation and Structure Investigation of Diastereomeric 4-OxasteroidsThe total synthesis of racemic 3-methyl-4-oxa-5.7.9.14-estratetraen-17-ol (8b) and 3-methyl-4-oxa-5.7.9-estratrien-17-ol (13b) is described. The n.m.r. spectra show that there is no induction of chirality from the chiral center at carbon C-3 to the newly formed center at carbon C-13 in this particular case.
    Notes: Es wird die Totalsynthese von racemischem 3-Methyl-4-oxa-östratetraen-(5.7.9.14)-ol-(17) (8b) und 3-Methyl-4-oxa-östratrien-(5.7.9)-ol-(17) (13b) beschrieben. Auf Grund der NMR-Spektren läßt sich nachweisen, daß eine Induktion der Chiralität von einem chiralen Zentrum am Kohlenstoffatom C-3 zum neu gebildeten Zentrum am Kohlenstoffatom C-13 im hier aufgezeigten Falle nicht erfolgt.
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 2419-2420 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 185
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 1646-1650 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Determination of the Structure of a New Synthetic Tetracyanopicolin by Mass SpectrometryConversion of the methyl groups of 3.5-dicyanocollidin into cyano groups yields pentacyanopyridine and a homogeneous tetracyanopicoline. The structure of the latter (4a) was determined by mass spectrometry.
    Notes: Wenn die Methylgruppen des 3.5-Dicyan-collidins in Cyan-Gruppierungen umgewandelt werden, fällt neben Pentacyanpyridin ein einheitliches Tetracyanpicolin an, dessen Struktur 4a massenspektrometrisch festgelegt wurde.
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 1694-1700 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Polyacetylenic Compounds, 206On the Constituents of Anacyclus pyrethrum DC.The investigation of the root extract of Anacyclus pyrethrum DC. yields besides previously known constituents further amides (10, 20-22). Their structures are established by spectral data and in part by synthesis.
    Notes: Die Untersuchung des Wurzelextraktes von Anacyclus pyrethrum DC. ergibt neben den bereits bekannten Inhaltsstoffen weitere Amide (10, 20-22), deren Strukturen durch ihre spektroskopischen Daten sowie z. T. durch Synthese geklärt werden.
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 1714-1717 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cycloacylation of 1-(Cyanoamino)adamantane with Bifunctional Acyl Chlorides and some Subsequent ReactionsAddition of oxalyl chloride to 1-(cyanoamino)adamantane (1) gave the dichloro compound 2. Hydrolysis of 2 yielded 1-(1-adamantyl)parabanic acid (3), and reaction of 2 with bifunctional nucleophilic agents afforded the spiro-compounds 6-9. Elimination of HCl from 2 followed by treatment with sec. amines gave 1-(1-adamantyl)-2-amino-2-imidazoline-4.5-diones 11a-e. Reaction of 1.1-cyclobutanedicarboxylic acid dichloride with 1 and subsequent hydrolysis led to the formation of the barbituric acid derivative 13.
    Notes: Durch Addition von Oxalylchlorid an Adamantyl-(1)-cyanamid (1) wurde die Dichlorverbindung 2 erhalten, die hydrolytisch in 1-[Adamantyl-(1)]-parabansäure (3) sowie mit bifunktionellen nucleophilen Reaktionspartnern in die Spiro-Verbindungen 6-9 übergeführt wurde. Durch Dehydrohalogenierung und Umsetzung mit sek. Aminen wurden aus 2 die 2-Amino-1-[adamantyl-(1)]-δ2-imidazolindione-(4.5) 11a-e erhalten. Nach Addition von Cyclobutan-dicarbonsäure-(1.1)-dichlorid an 1 und Hydrolyse wurde das Barbitursäure-derivat 13 isoliert.
    Additional Material: 2 Tab.
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  • 188
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 1755-1758 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Compounds with Urotropin Structure, L. Cyclization Reactions Starting with cis-3.5-Diaminocyclohexanolcis-3.5-Diaminocyclohexanol, isolated as the diacetyl derivative (5), is prepared in good yields by a new method starting from 3.5-dinitrophenol (1). Condensation of 5 and cis-3.5-bis(phenylsulfonylamino)cyclohexanol (8) with triethyl orthoformate leads to the formation of N.N′-diacetyl-(4) and N.N′-bis(phenylsulfonyl)-2-oxa-4.10-diazaadamantane (6), respectively. 4-Acetyl-3-methyl-2-oxa-4.10-diazaadamantane (3) is formed simultaneously by intramolecular transacetalization.
    Notes: Ausgehend vom 3.5-Dinitro-phenol (1) wird eine neue, ergiebige Methode zur Herstellung des cis-3.5-Diamino-cyclohexanols, gewonnen als Diacetylderivat (5), beschrieben. Durch Kondensation von 5 und von cis-3.5-Bis-benzolsulfonylamino-cyclohexanol (8) mit Orthoameisensäure-triäthylester sind N.N′-Diacetyl-(4) und N.N′-Bis-benzolsulfonyl-2-oxa-4.10-diaza-adamantan (6) zugänglich. Gleichzeitig wurde durch intramolekulare Umacetalisierung das 3-Methyl-4-acetyl-2-oxa-4.10-diaza-adamantan (3) erhalten.
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  • 189
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 105 (1972) 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 190
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 2047-2057 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Pseudohalogeno Compounds, XVII. CF3S-substituted Cyanamides, Chloroformamidines and their Chemical PropertiesCF3SCl reacts with cyanamide according to the reaction conditions to give N.N′-bis- (1) or N.N.N′-tris(trifluoromethylsulfenyl)chloroformamidine (2). 1 reacts with cyanamide to yield (trifluoromethylsulfenyl)cyanamide (3). Dialkylcyanamides and CF3SCl to form 5a and b, while monosubstituted cyanamides react with CF3SCl to form N-alkyl-N.N′-bis(trifluoromethylsulfenyl)chloroformamidines (4a, b). The reaction with tert-butylcyanamide leads only to the formation of N-tert-butyl-N-(trifluoromethylsulfenyl)cyanamide (5). The corresponding methyl- (7a) and isopropyl compounds (7b) are obtained by heating 4a or b. In the presence of moisture 7a, b hydrolyse to the unsymmetrically disubstituted ureas 9a, b. Hexakis(trifluoromethylsulfenyl)melamine (12) is synthesized from 1 and trimethylamine, 2 and pyridine, 10 and CF3SCI as well as from 14 and CF3SCl. The trisubstituted melamine 13 is made from melamine and CF3SCI in the presence of pyridine. Physical and chemical properties are given.
    Notes: CF3SCl reagiert je nach Reaktionsbedingungen mit Cyanamid zu N.N′-Bis- (1) bzw. N.N.N′-Tris(trifluormethylsulfenyl)-chlorformamidin (2). Mit Cyanamid setzt sich 1 zum Trifluormethylsulfenylcyanamid (3) um. Dialkylcyanamide addieren CF3SCl zu 6a und b, monosubstituierte liefern N.N′-Bis(trifluormethylsulfenyl)-N-alkyl-chlorformamidine (4a, b). Aus tert.-Butylcyanamid und CF3SCl entsteht dagegen nur N-Trifluormethylsulfenyl-N-tert.-butyl-cyanamid (5). Die entsprechenden Methyl- (7a) bzw. Isopropylverbindungen (7b) bilden sich beim Erhitzen von 4a, b. An feuchter Luft hydrolysieren 7a, b zu den unsymmetrisch substituierten Harnstoffen 9a, b. Hexakis(trifluormethylsulfenyl)-melamin (12) bildet sich aus 1 und Trimethylamin, 2 und Pyridin, 10 und CF3SCl sowie 14 und CF3SCl. Das trisubstituierte Melamin 13 wurde aus Melamin und CF3SCl in Gegenwart von Pyridin erhalten. Physikalische und chemische Eigenschaften sind angegeben.
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  • 191
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 2089-2094 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Crystal and Molecular Structure of triptych-Boroxazolidine (Triethanolamine Borate)The crystal structure of triptych-boroxazolidine, C6H12BNO3, has been determined by X-ray diffraction. The intensity data were collected by a Pailred diffractometer and the structure was solved by direct methods. The molecule has threefold symmetry along the intermolecular B—N bond with the length 1.677 ± 0.006 Å.
    Notes: Die Struktur von triptych-Boroxazolidin, C6H12BNO3, wurde röntgenographisch mit Hilfe direkter Methoden bestimmt. Das Molekül besitzt eine dreizählige Symmetrieachse entlang einer innermolekularen B—N-Bindung mit der Länge 1.677 ± 0.006 Å.
    Additional Material: 2 Ill.
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  • 192
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 2101-2103 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 3.3-Dimethyl-3H-3-benzosilepin and 3H-3-BenzosilepinThe reaction of 3.3-dichloro-3H-3-benzosilepin (1) with methyl lithium leads to 3.3-dimethyl-3H-3-benzosilepin (2). 2 is reduced with tris-(tert.-butoxy)-lithium aluminium hydride to 3H-3-benzosilepin (3). 2 and 3 are investigated by i.r. and n.m.r. spectroscopy and by mass spectrometry.
    Notes: Die Umsetzung von 3.3-Dichlor-3H-3-benzosilepin (1) mit Methyllithium führt zu 3.3-Dimethyl-3H-3-benzosilepin (2). Die Reduktion von 2 mit Tris-[tert.-butyloxy]-lithiumaluminiumhydrid ergibt 3H-3-Benzosilepin (3). 2 und 3 wurden IR- und NMR-spektroskopisch sowie massenspektrometrisch untersucht.
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  • 193
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions with Indole Derivatives, XVII. The Biogenetically Orientated Total-Synthesis of DL-Camptothecin and 7-ChlorocamptothecinThe biogenetically patterned transformation of the easily available indole derivative 3 via the compounds 4, 6, 10, 12, 15, 17, 20, and 24 into the anti-tumor alkaloid camptothecin (1) as well as 7-chlorocamptothecin (2) is described.
    Notes: Es wird die biogenetisch orientierte Überführung der Indolvorstufe 3 über die Verbindungen 4, 6, 10, 12, 15, 17, 20 und 24 in das anti-Tumor-wirksame Alkaloid Camptothecin (1) sowie in das 7-Chlor-camptothecin (2) beschrieben.
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  • 194
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 2182-2187 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Constituents of Piper methysticum Forst., V. 11-Hydroxy-12-methoxydihydrokawain and 11.12-Dimethoxydihydrokawain, two new Kawa-Lactones from Piper methysticum Forst.Chromatographic separation of the methanolic extract from kawa-roots yielded two new lactones, which were shown to have the structures 1 and 2.
    Notes: Die chromatographische Untersuchung des methanolischen Extraktes der Kawa-Wurzel führte zur Isolierung der neuen Kawa-Lactone 1 und 2.
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  • 195
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 2143-2155 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Enehydrazines, 4. The Reaction of Dimedone with HydrazonesIn the presence of p-toluenesulfonic acid dimedone reacts with araliphatic or aromatic hydrazones to form enehydrazones such as 4, 6, 8, and 10, which can be hydrogenated to the enehydrazines 12, 13, and 15. Under mild acid catalysis dimedone reacts with hydrazones (including aliphatic ones) to yield tetrahydroindazolinones 16 to 19, and 22 via hexahydroindazolinones such as 25 to 28.
    Notes: Dimedon bildet bei Gegenwart von p-Toluolsulfonsäure mit araliphatischen oder aromatischen Hydrazonen Enhydrazone wie 4, 6, 8 und 10, die zu den Enhydrazinen 12, 13 und 15 hydriert werden können. Bei milder Säurekatalyse entstehen aus Dimedon und (auch aliphatischen) Hydrazonen über die Stufe der Hexahydro-indazolinone-(4) wie 25-28 die Tetrahydro-indazolinone 16-19 und 22.
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  • 196
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 2216-2227 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses with Enamines, XIX. On the Influence of Various Factors on the Reaction of Cyclic Enamines with KetenesCyclic enamines 1 are acylated by acetyl chloride directly to 5. In the presence of tert. aliphatic amines 6 is first formed and reacts  -  depending on the ring size of the enamine, the amino group, and the solvent  -  to 5 and/or 4. The cycloadducts 4 (n = 6-9) isomerize to 5 while the larger ring adducts 4 (n = 9-13) isomerize to 7.5 and 7 are obtained as their hydrolysis products 8 and 11. All known factors, which influence the acylation of enamines, are documented.
    Notes: Cyclische Enamine 1 werden von Acetylchlorid direkt zu 5 acyliert, in Gegenwart von tert. aliphatischen Aminen entsteht zunächst der Dipol 6, der in Abhängigkeit von der Ringgröße des Enamins, des Aminrestes sowie des Solvens zu 5 und/oder 4 reagiert. Die Cycloaddukte 4 (n = 6-9) isomerisieren zu 5, die größeren Ringe 4 (n = 9-13) dagegen zu 7 unter Ringerweiterung. 5 und 7 werden über ihre Hydrolyseprodukte 8 und 11 erfaßt. Alle bekannten Faktoren, welche die Acylierung von Enaminen beeinflussen, werden zusammengestellt.
    Additional Material: 4 Tab.
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  • 197
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 3138-3160 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: s-Triazinethiones, VReaction of N-substituted Amidino Compounds with Acyl Isothiocyanates The reaction of aroyl isothiocyanates and of ethoxycarbonyl isothiocyanate with N-phenyl-amidino compounds in many cases affords mixtures of an N-phenyltriazinethione (1-3, 7) and an N-imidoyl-N'-aroylthiourea (1:1-adduct) (4-6, 8). The triazines originate by reaction of the substituted N of the amidines, the thioureas by addition to the NH-group of the bases. The latter reaction is the more general one. The ratio of the yields depends strongly on the reaction temperature and on the type of amidino compound. The reaction of S-alkyl-N-phenylisothioureas is an exception in that it results in preferential formation of the triazine. Apart from these concurring reactions transacylation (transfer of the aroyl group to the amidine) may occur, depending on the electrophilic strength of the isothiocyanates. - The 1:1-adducts do not form triazines spontaneously or thermically, but compounds with suitable leaving groups can be cyclized by treatment with alkali.
    Notes: Die Reaktion von Aroylsenfölen und Äthoxycarbonylsenföl mit N-Phenyl-amidino-Verbindungen führt in vielen Fällen zu Gemischen von N-Phenyl-triazinthionen (1-3, 7), bedingt durch Reaktion am substituierten N des Amidins, und N-Imidoyl-N-aroyl-thioharnstoffen (1:1-Addukten) (4-6, 8), bedingt durch Reaktion an der NH-Gruppe des Amidins. Die letztgenannte Reaktion ist die allgemeinere. Das Verhältnis von Triazin und 1:1-Addukt ist stark abhängig von der Reaktionstemperatur und von der Art der Amidino-Verbindung. Hierbei nehmen die S-Alkyl-N-phenyl-isothioharnstoffe eine Sonderstellung ein (Bevorzugung des Triazins). Daneben spielt noch die Acylierungsreaktion (Übertragung des Aroylrestes auf das Amidin) eine Rolle, abhängig von der Elektrophilie des Senföls. - Die 1:1-Addukte bilden weder spontan noch thermisch Triazine. Solche mit geeigneten Abgangsgruppen können aber durch Alkali cyclisiert werden.
    Additional Material: 6 Tab.
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  • 198
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation of Polyalkylthio- and Polyarylthiomethanes, -ethanes and -ethylenes from Metalated OrthotrithioformatesAliphatic, cycloaliphatic, and aromatic thioles are converted to orthotrithioesters in good yields by treatment with trimethyl orthoformate in the presence of Lewis acids; open chain, monocyclic and bicyclic derivatives 4a-s and 8 are prepared. Methods for the unambiguous synthesis of tristhiomethanes with two different RS-groups are described. Metalated orthotrithioformates 1 are obtained form 4 and n-butyllithium in THF at -70° as shown by quantitative isolation of the 1.1.1-tristhioethanes 5 after reaction with iodomethane. The organometallic compounds 1 decompose to give tetrakisthioethylenes 6. Decomposition takes place, thermally“ between -50 and -20° in the case of open chain alkyl derivatives 1 while the aryl analogs must be, decomposed“ with cyclohexene epoxide. The tetrakisthiomethanes 7, 9, 17, 18 and 19 are prepared form metalated formaldehyde dithioacetals or orthotrithioformates and disulfides.
    Notes: Aliphatische, cycloaliphatische und aromatische Thiole liefern in Gegenwart von Lewis-Säure mit Orthoameisensäure-trimethylester in guten Ausbeuten die offenkettigen, monocyclischen und bicyclischen Trithioester 4a-s und 8. Methoden zur gezielten Herstellung von Derivaten mit zwei verschiedenen RS-Gruppen werden beschrieben. Die Orthotrithioester werden bei -70° in THF durch Butyllithium quantitativ zu 1 metalliert. Aus den Metallderivaten 1 und Methyljodid entstehen die 1.1.1-Tris-mercapto-äthane 5. Zerfall von 1 liefert die Tetrakis-mercapto-äthylene 6; die alkylsubstituierten Verbindungen 1 zerfallen schon bei Temperaturen zwischen -50 und -20°; um Tetrakis-arylmercapto-äthylene herzustellen, muß man die entsprechenden Verbindungen 1 mit Cyclohexenoxid, zersetzen“. Thiolierungen von metallierten Formaldehyd-dithioacetalen und Orthotrithioameisensäureestern mit Disulfiden führen zu den Tetrakis-mercapto-methanen 7, 9, 17, 18 und 19.
    Additional Material: 5 Tab.
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  • 199
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    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 3322-3326 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thioacyl Isocyanates, VIIIReaction with Ketenes and Ketene Imines to Form 1.3.5-Oxathiazines and 1.3.5-ThiadiazinesThiobenzoyl isocyanate undergoes 4 + 2 cycloaddition with aromatic ketenes and aromatic ketene imines to yield the title heterocyclic compounds (2a-e, 3a-d).
    Notes: Thiobenzoyl-isocyanat reagiert mit aromatischen Ketenen und aromatischen Keteniminen im Sinne einer 4 + 2-Cycloaddition zu den Heterocyclen 2a-e und 3a-d der Überschrift.
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  • 200
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 3382-3388 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Trimethylphosphine Complexes of CuCl and AgCl:Synthesis, N.M.R. and N.Q.R. Spectra Tetrameric complexes [(CH3)3PMCl]4, dimeric species {[(CH3)3P]2MCl}2, monomeric [(CH3)3P]3MCl, and unstable, probably ionic compounds [(CH3)3P]4M⊕Cl⊖ have been obtained from (CH3)3P and CuCl or AgCl, resp. (M = Cu, Ag). These new compounds were characterized by i.r., 1H n.m.r., 35Cl and 63Cu n.q.r. spectra and the results compared and discussed.
    Notes: Aus (CH3)3P und CuCl bzw. AgCl wurden tetramere Verbindungen der Zusammensetzung [(CH3)3PMCl]4, Dimere der Formel {[(CH3)3P]2MCl}2, Monomere [(CH3)3P]3MCl und instabile, vermutlich ionisch aufgebaute Komplexe des Typs [(CH3)3P]4M⊕Cl⊖ erhalten (M = Cu, Ag). Diese Koordinationsverbindungen wurden mit Hilfe der IR-, 1H-NMR-, 35Cl- und 63Cu-NQR-Spektroskopie näher charakterisiert und die Ergebnisse vergleichend diskutiert.
    Additional Material: 4 Tab.
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