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  • 1970-1974  (3,904)
  • Organic Chemistry  (3,415)
  • Engineering General  (489)
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  • 1
    Electronic Resource
    Electronic Resource
    A note on solving integral equations with Gauss-Legendre quadrature (1974)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 8 (1974), S. 913-914 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620080415
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  • 2
    Electronic Resource
    Electronic Resource
    Least squares finite element analysis of laminar boundary layer flows (1974)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 8 (1974), S. 865-876 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Based on the least squares error criterion, a class of finite element is formulated for the numerical analysis of steady state viscous boundary layer flow problems. The method is essentially a discrete element-wise minimization of square and weighted residuals which arise from the attempts in approximately satisfying boundary layer equations. An iterative linearization scheme is developed to circumvent the mathematical difficulties posed by the non-linear boundary layer equations. It results in a process of successive least squares minimizations of residual errors arising from satisfying a set of linear differential equations. A mathematical justification for the method is presented. A major feature of the method lies in the linearization approach which renders non-linear differential equations amenable to linear least squares finite element analysis. Another important feature rests on the proposed finite element formulation which preserves the symmetric nature of finite element matrix equations through the use of the least squares error criterion. Numerical examples of viscous flow along a flat plate are presented to demonstrate the applicability of the method as well as to illuminate discussions on the theoretical aspects of the method.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620080413
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  • 3
    Electronic Resource
    Electronic Resource
    Eigenproblem solution of damped structural systemsThis paper presents the results of one phase of research carried out at the Jet Propulsion Laboratory, California Institute of Technology, under Contract No. NAS 7-100, sponsored by the National Aeronautics and Space Administration. (1974)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 8 (1974), S. 877-911 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: This article presents an efficient numerical algorithm a complete listing of the associated computer program, developed for the eigenproblem solution of discrete damped structures, including spinning ones. The numerically stable procedure is based on a combined Sturm sequence and inverse iteration technique, which fully exploits the banded form of the relevant matrices and proves to be most substantially economical when compared to similar existing softwares. Numerical results are presented for representative structures, solved by the present computer program written in FORTRAN V for the JPL UNIVAC 1108 computer.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620080414
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  • 4
    Electronic Resource
    Electronic Resource
    A few remarks on the paper: ‘Parameters of Gamma and Beta distribution’ (1974)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 8 (1974), S. 914-916 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The paper shows a procedure for estimating the shape parameter of a Gamma distribution from a sample. This procedure uses a rapidly converging iteration to solve the maximum-likelihood equation and suggests a simple formula for determing the starting value.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620080416
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  • 5
    Electronic Resource
    Electronic Resource
    Announcements (1974)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 8 (1974), S. 917-918 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620080418
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  • 6
    Electronic Resource
    Electronic Resource
    Numerical solution of partial differential equations, Edited by J. Gram, D. Reidel, Amsterdam, 1973, Price : ƒ62 (1974)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 8 (1974), S. 917-917 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620080417
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  • 7
    Electronic Resource
    Electronic Resource
    Masthead (1974)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 8 (1974) 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620080101
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  • 8
    Electronic Resource
    Electronic Resource
    A note on some variational statements for the slow flow of a Navier-Poisson fluid (1974)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 8 (1974), S. 17-25 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Three variational statements for the slow time-independent flow of a Navier-Poisson fluid are derived. All of these statements are suitable as the bases of finite elements. The first statement is applied successfully to several flow situations.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620080103
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  • 9
    Electronic Resource
    Electronic Resource
    The static condensation algorithm (1974)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 8 (1974), S. 198-203 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The application of the static condensation method is discussed in general. The technique is presented as an extension of the Gauss elimination algorithm. An efficient FORTRAN subroutine is given which simultaneously reduces both the stiffness matrix and the stress-displacement transformation matrix.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620080115
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  • 10
    Electronic Resource
    Electronic Resource
    A technique for degenerating brick-type isoparametric elements using hierarchical midside nodes (1974)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 8 (1974), S. 203-209 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620080116
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  • 11
    Electronic Resource
    Electronic Resource
    Discussion of a short communication‘A higher order conforming, rectangular plate element’, Int. J. num. Meth. Engng, [6], 305-308 (1973). by S. Gopalacharyulu (1974)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 8 (1974), S. 209-212 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620080117
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  • 12
    Electronic Resource
    Electronic Resource
    Applications of the theory of distribtuions, R. Cristescu and G. Marinescu, Wiley, London, 1973. No. of pages : 227. Price : £3.75 (1974)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 8 (1974), S. 212-212 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620080118
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  • 13
    Electronic Resource
    Electronic Resource
    Announcement (1974)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 8 (1974), S. 212-212 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620080119
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  • 14
    Electronic Resource
    Electronic Resource
    Masthead (1974)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 8 (1974) 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620080201
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  • 15
    Electronic Resource
    Electronic Resource
    Restrictions in the application of automatic mesh generation schemes by ‘isoparametric’ co-ordinates (1974)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 8 (1974), S. 289-294 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: To obtain meshes of reasonable form there have to be made some restrictions in the application of automatic mesh generation schemes using ‘isoparametric’ co-ordinates. In this present paper it will be shown that such restrictions exist for plane meshes. The results figured here are also valid for three-dimensional meshes.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620080208
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  • 16
    Electronic Resource
    Electronic Resource
    Finite element approach to bending of micropolar plates (1974)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 8 (1974), S. 311-321 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620080210
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  • 17
    Electronic Resource
    Electronic Resource
    Optimization of complex structures to satisfy static, dynamic and aeroelastic requirements (1974)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 8 (1974), S. 249-269 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A structural optimization problem is considered in which the design requirements include restrictions on the strength, stability, frequency and flutter characteristics of the structure. One of the central concerns of this phase of the work has been to overcome the problems inherent in analysing the dynamic and aeroelastic behaviour of structures with many degrees of freedom. The multiweb delta wing structure under supersonic flight conditions is the model upon which this exploratory study is based. The finite element idealization, with three different kinds of elements, is used to model the wing structure. The constant stress triangular plate elements, the rectangular shear panels and the pin-jointed bar elements are used to represent, respectively, the cover skins, webs and stringers of the wing structure. The design problem is formulated as a minimum weight optimization problem and is solved by using non-linear programming techniques. Computationally efficient schemes are developed for the necessary derivatives of the behaviour constraints. Numerical examples are presented to illustrate the feasibility and the computational effectiveness of the method.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620080205
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  • 18
    Electronic Resource
    Electronic Resource
    Exponential fitting using integral equations (1974)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 8 (1974), S. 271-276 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The fitting of a function y =\documentclass{article}\pagestyle{empty}\begin{document}$ \sum\nolimits_{i = 1}^n {A_i {\rm{e}}^{\lambda ix}} $\end{document} to experimental data is considered. Integral equations are developed which have the functions \documentclass{article}\pagestyle{empty}\begin{document}$ \sum\nolimits_{i = 1}^n {A_i {\rm{e}}^{\lambda ix}} $\end{document} as their solutions for n = 1, 2, 3, These integral equations are used to find the frequencies λi. Examples are worked out to illustrate the method. The method is shown to be capable of extension to other functions.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620080206
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  • 19
    Electronic Resource
    Electronic Resource
    The finite element analysis of elasto-plastic materials by use of dislocation dipole systems (1974)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 8 (1974), S. 277-288 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: It is shown how the stress field due to any prescribed continuous distribution of dislocation dipoles can be determined. This technique then forms the basis of a general method of solution of elasto-plastic material problems. The presentation is limited to situations which conform to either plane stress or strain conditions. Some results are obtained for relatively simple geometrical and loading configurations and compared with classical plasticity solutions. Finally, the method is applied to the problem of a circular hole in a finite strip under tension.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620080207
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  • 20
    Electronic Resource
    Electronic Resource
    Finite element solutions for an equilateral triangle (1974)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 8 (1974), S. 495-501 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: In a two-dimensional space of points on an equilateral triangle grid, a single difference equation holding at each node is found from the finite element formulation of the wave equation for all published polynomial orders of the functional expansion. Assuming homogeneous boundary conditions on any equilateral triangle whose edges and vertices pass through the grid points, the eigensolutions of the difference equation are found exactly and thus provide an excellent test problem for the programmer or engineer. The advantage of the present method over other formulations is that the number of linear operations required to produce the difference equation is minimal.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620080305
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  • 21
    Electronic Resource
    Electronic Resource
    Transient two-dimensional heat conduction problems solved by the finite element method (1974)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 8 (1974), S. 481-494 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A finite element weighted residual process has been used to solve transient linear and non-linear two-dimensional heat conduction problems. Rectangular prisms in a space-time domain were used as the finite elements. The weighting function was equal to the shape function defining the dependent variable approximation. The results are compared in tables with analytical, as well as other numerical data. The finite element method compared favourably with these results. It was found to be stable, convergent to the exact solution, easily programmed, and computationally fast. Finally, the method does not require constant parameters over the entire solution domain.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620080304
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  • 22
    Electronic Resource
    Electronic Resource
    Bicubic fundamental splines in plate bending (1974)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 8 (1974), S. 503-511 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: This paper deals with solving the two-dimensional variational problem for plate bending by the Ritz method using bicubic fundamental splines. It is a piecewise polynomial method, very adaptable to practical numerical computation, and can be an alternative for the well-known Finite Element Method1.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620080306
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  • 23
    Electronic Resource
    Electronic Resource
    Observations regarding assumed-stress hybrid plate elements (1974)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 8 (1974), S. 513-519 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Edge displacement of assumed-stress hybrid plate elements are commonly chosen as either linear, quadratic or cubic functions of the edge co-ordinate. The present paper examines the effect of this choice on the acceptability, accuracy, and possible zero energy modes of elements based on a linear stress field. It is concluded that triangular elements may be preferable to quadrilaterals, and that linear edge displacements are not desirable.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620080307
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  • 24
    Electronic Resource
    Electronic Resource
    Cycle bases for the flexibility analysis of structures (1974)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 8 (1974), S. 521-528 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Two methods are presented for the automatic selection of a cycle basis leading to a sparse flexibility matrix for the analysis of rigid-jointed skeletal structures.The first method having a local approach forms a maximal set of admissible minimal cycles, while the second having a global approach constructs admissible minimal cycles on the ordered chords of a shortest route tree. A cycle ordering algorithm is also given to reduce the band width of the corresponding flexibility matrix.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620080308
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  • 25
    Electronic Resource
    Electronic Resource
    Spline-blended approximation of Hartmann's flow (1974)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 8 (1974), S. 529-536 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The steady state flow problem known in magnetohydrodynamics as Hartmann's flow is converted into variational formulation and is given an approximate solution by means of the spline blended interpolation technique. The equations of motion consist of two coupled potential flow problems with homogeneous boundary conditions. The spline blended interpolation method is reduced here, because of the shape of the domain, to a cartesian product of cardinal splines with trigonometric or ordinary polynomials. ‘Exact’ boundary conditions are presented by the blending technique. The numerical results indicate that high accuracy is possible with relatively few unknowns.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620080309
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  • 26
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    Representation of singularities with isoparametric finite elementsThis work was supported by the United States Atomic Energy Commission. (1974)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 8 (1974), S. 537-545 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The development of a generalized quadrilateral finite element that includes a singular point at a corner node is presented. Inter-element conformability is maintained so that monotone convergence is preserved. The global-local concept of finite elements is used to formulate the complete set of equations. Examples of crack tip singularities are given.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620080310
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  • 27
    Electronic Resource
    Electronic Resource
    Finite element solution of non-linear heat conduction problems with special reference to phase change (1974)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 8 (1974), S. 613-624 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The paper presents a generally applicable approach to transient heat conduction problems with non-linear physical properties and boundary conditions. An unconditionally stable central algorithm is used which does not require iteration.Several examples involving phase change (where latent heat effects are incorporated as heat capacity variations) and non-linear radiation boundary conditions are given which show very good accuracy.Simple triangular elements are used throughout but the formulation is generally valid and not restricted to any single type of element.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620080314
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  • 28
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    Visco-plasticity - plasticity and creep in elastic solids - a unified numerical solution approach (1974)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 8 (1974), S. 821-845 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The visco-plastic model of material behaviour is of much practical interest in its own right and initial strain techniques for its solution have been developed and proved efficient. More important however is the fact that the visco-plastic model can be used to generate plasticity solutions in a simple manner when stationary conditions are reached and, at the other extreme, can reproduce standard creep phenomena. Used in this sense it allows the treatment of non-associated plasticity and strain softening situations which present difficulties in conventional plasticity approaches. A standard programme thus allows the treatment of a wide range of materially non-linear problems.The paper discusses various applications of the new general formulation and introduces certain numerical information on solution stability.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620080411
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  • 29
    Electronic Resource
    Electronic Resource
    Acrylsäureamide aus metallierten Keteniminen und Carbonylverbindungen (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1655-1660 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Acrylamides from Metalated Ketenimines and Carbonyl CompoundsMetalated N-phenyl-phenylketenimines 7 react with benzaldehyde or α,β-unsaturated aldehydes via carbonyl olefination to give α-phenylacrylaniklides 13. The reagents 7 were prepared from 1,4-Diphenyl-H-1,2,3-triazol-5yllithium (5) by nitrogen elimination or from N-phenyl-phenylketenimine (6) by metalation with potassium tert.-butoxide.
    Notes: Metallierte N-Phenyl-phenylketenimine 7 reagieren mit Benzaldehyd oder α-β-ungesättigten Aldehyden in einer Carbonylolefinierung zu α-yllithium 13. Die Reagentien 7 erhielt man aus 1,4-Diphenyl-1H-1,2,3-triazol-5-5yllithium (5) durch Stickstoffabspaltung und aus NPhenyl-phenylphenylketenimin (6) durch Metallierung mit Kalium-tert.-butylalkoholat.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419741016
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  • 30
    Electronic Resource
    Electronic Resource
    Radioaktive Markierung von Tropan-Alkaloiden, VI1) Darstellung von [N-Methyl-T1]Psicain-neu und von polytop tritiiertem Psicain (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1650-1654 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Labelled Tropane Alkaloids, VI1). - Syntheses of [N-Methyl-T1] Psicain-neu and of Polytopically Tritiated PsicainThe reaction of norpsicain-neu (3) WITH cth2I yielded [N-methyl-T1] Psicain-neu (4), isolated as hydrochloride (activity 51.65 mCi/mmol). Polytopic tritiation of psicain (2) by a modified Wilzbach method yielded a product which was also isolated as hydrochloride with an activity of 30.8 mCi/mmol. The distribution of tritium in [3H]psicain in the benzoic acid, in the pseudoecgonine, and in the CH3O group was 84.5: 11.5:4 per cent.
    Notes: Durch Umsetzung von Norpsicain-neu (3) mit CTH2J wurde [N-Methyl-T1]Psicain-neu (4) dargestellt und als Hydrochlorid isoliert (Aktivität 51.65 mCi/mmol). Die polytope Tritiierung von Psicain (2) nach einer modifizierten Wilzbach-Methode ergab ein ebenfalls als Hydrochlorid isoliertes Produkt mit einer Aktivität von 30.8,Ci/mmol. Die prozentuale Verteilung des Tritiums im [3H]Psicain auf die Benzoesäure-, auf die Pseudoecgonin- und auf die CH3O- Gruppierungen betrug 84.5:11.5:4.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/jlac.197419741015
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    Untersuchungen an Diazoverbindungen und Aziden, XXI1) Sigmatrope (1,5)-Acylverschiebung bei der Cycloaddition von 2-Diazocycloalkanonen an aktivierte Acetylene (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1702-1708 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Investigations on Diazo Compounds and Azides, XXI1). - Sigmatropic (1,5)-Acyl Shifts in the Cycladdition of 2-Diazocycloalkanones to Activated AcetylenesThe 2-diazocycloalkanones 1a-f react with dimethyl acetylenedicarboxylate to give the bicyclic compounds 3a-f via the pyrazolenine intermediates -f The reaction 2 → 3 is interpreted as a sigmatropic (1,5)-acyl shift. In the same way acetylenedicarbonitrile, hexafluoro-2-butyne, butyn-3-one and methyl propiolate with 1 with formation of 4a-d, respectively. On hydrolysis in alkaline medium, the bicyclic compounds 3a-f give the tricarboxylic acids 5a-f.
    Notes: Die 2-Diazocycloalkanone 1a-f reagieren mt Dimethyl(acetylenidicarboxylat) über die Pyrazolenin-Zwischenstufen 2a-f zu den Bicyclen 3a-f. Der Übergang 2 → 3 wird als sigmatrope (1,5)-Acylverschiebung interpretiert. Im gleichen Sinne reagieren Acetylendicarbonitril, Hexafluor-2-butin, Butin-3-on und Methylpropiolat mit 1b zu 4a-d. - Die Bicyclen 3a-f werden in alkalischem Medium zu den Tricarbonsäuren 5a-f hydrolysiert.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/jlac.197419741023
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    Chemie und Biochemie der Pflanzenstoffe, XXXIV1) C-Benzoylierung von 2′,4′-Dihydroxyacetophenonglykosiden mit 4-Formyl-1,2-phenylendibenzoat (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1709-1712 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Chemistry and Biochemistry of Plant Constituents, XXXXIV1). - C-Benzoylation of 2′,4′-Dihydroxyacetophenone Glycosides with 4-Formyl-1,2-phenylene DibenzoateReaction of the 2′,4′-dihyroxyaetophenone glycosides 1 and 6 with 4-formyl-1,2-phenylene dibenzoate affords the 3′-benzoyl compounds 2 and 7. The structures are elucidated by nitration to 3, 4, and 5.
    Notes: Bei der Reaktion der 2′,4′-Dihydroxyacetophenonglykoside 1 und 6 mit 4-Formyl-1,2-phenylendibenzoat entstehen die 3′-Benzoylverbindungen 2 und 7. Deren Strukturen werden durch Nitrierung zu 3, 4 und 5 bewiesen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419741024
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  • 33
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    Lösungsmitteleffekte bei Radikalreaktionen, I. Einfluß der Lösungsmittelpolarität auf die Zersetzung von 7-Cumylhydroperoxid und die Autoxidation von Cumol in Gegenwart von Kobalt(II)-acetylacetonat (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1713-1725 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Solvent Effects in Radical Reactions, I. - Influence of Solvent Polarity on Decomposition of 7-Cumenyl Hydroperoxide and Autoxidation of Cumene in Presence of Cobalt(II) AcetylacetonateThe decomposition of 7-cumenyl hydroperoxide in the presence of cobalt(II) acetylacetonate in nitrobenzene at 60 °C proceeded via an intermediate complexe of hydroperoxide and metal compound, which decays exclusively into free radicals. The polarity of solvent (nitrobenzene, benzene or mixtures thereof) has no effect on the decomposition rate and the radical yield. The catalyst is poisoned during the reaction. - Contrary to the autoxidation of cumene initiated by 2,2′-azodiisobutyronitrile, the rate of which is increased in nitrobenzene solution, the rate of the reaction catalyzed by cobalt(II) acetylacetonate is decreased by the addition of nitrobenzene. - The mechanisms are discussed.
    Notes: Die Zersetzung von 7-Cumylhydroperoxid in Gegenwart von Kobalt(II)-acetylacetonat in Nitrobenzol ei 60 °C verläuft über einen Komplex aus Hydroperoxid und Schwermetallverbindung, der ausschließlich zu freien Radikalen reagiert. Die Polarität des Lösungsmittels (Nirtobenzol, Benzol oder deren Gemische) ist ohne Einfluß auf die Zersetzungsgeschwindigkeit und die Radikalauseute. Der Katalysator wird im Verlauf der Reaktion vergiftet. - Unterschiedlich zu der durch 2,2′-Azodiisobutyronitril initiierten Autoxidation von Cumol, die in Nitrobenzol rascher abläuft als ohne Lösungsmittel, wird die durch Kobalt(II)-acetyl-acetonat katalysierte Reaktion durch den Zusatz von Nitrobenzol. - Die Mechanismen werden diskutiert.
    Additional Material: 10 Ill.
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    URL: http://dx.doi.org/10.1002/jlac.197419741025
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    Masthead (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974) 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419741101
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  • 35
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    Dakin-West-Reaktion, IV1) Umsetzung von α-Aminodicarbonsäuren mit Carbonsäureanhydriden2) (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1753-1762 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Dakin West Reaction, IV1). - Reaction of α-Amino Dicarboxylic Acids with Carboxylic Acid Anhydrides2)The Dakin West reaction of N-acylaspartic anhydrides yields furo[3,2-d]oxazoles 5 and 14, 2(5H)-furanones 8 or 6H-1,3-oxazin-6-ones 9, depending on the reaction conditions. N-Thiobenzoylaspartic acid is converted into 6H-1,3-thiazin-6-one (12) by treatment with acetic anhydride and 3-picoline. Glutamic acid gives 1,5-diacetyl-2-pyrrolidone (22) in high yield on warming with acetic anhydride and 4-(dimethylamino)pyridine. Possible mechanisms for the formation of the different products are discussed.
    Notes: N-Acylasparaginsäureanhydride liefern bei der Dakin-West-Reaktion je nach den Reaktionsbedingungen Furo[3,2-d]oxazole 5 und 14, 2(5H)-Furanone 8 oder 6H-1,3-Oxazin-6-one 9. Aus N-Thiobenzoylasparaginsäure, Acetanhydrid und 3-Picolin entsteht das 6H-1,3-Thiazin-6-on (12). Glutaminsäure wird von Acetanhydrid und 4-(Dimethylamino)pyridin in guter Ausbeute in 1,5-Diacetyl-2-pyrrolidon (22) übergeführt. Mechanismen für die Bildung der verschiedenen Produkte werden diskutiert.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/jlac.197419741104
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    “Azolato”-metallate des Kobalts, Nickels, Kupfers und Zinks (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1784-1788 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: “Azolato” Metalates of Cobalt, Nickel, Copper, and ZincThe cobalt(II), nickel, copper(II), and zinc derivatives (ML2) of imidazole, pyrazole, and 1.2.4-triazole (LH) exhibit an amphoteric behaviour. Comparable with that of metal hydroxides in yielding the corresponding “azolato”-metalates (in most cases [ML4)Na2) with the sodium compounds of the heterocycles in suitable solvents.
    Notes: Die Kobalt(II)-, Nickel-, Kupfer(II)- und Zink-Derivate (ML2) des Imidazols. Pyrazols und 1.2.4-Triazols (LH) zeigen ähnlich den Metallhydroxiden ein amphoteres Verhalten, indem sie mit den Natriumverbindungen der Heterocyclen in geeigneten Lösungsmitteln “Azolato”-metallate (vorzugsweise [ML4]Na2) bilden.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/jlac.197419741107
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    Untersuchungen an 1,3-Thiazinen, II1) Darstellung von Tetrahydro-1,3-thiazin-2,4-dionen durch oxidative Desulfurierung von 2-Thioxo-tetrahydro-1,3-thiazin-4-onen (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1789-1792 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Investigations on 1,3-Thiazines, II1). - Synthesis of Tetrahydro-1,3-thiazine-2,4-diones by Oxidative Desulfuration of 2-Thioxo-tetrahydro-1,3-thiazin-4-onesThe readily available 2-thioxo-tetrahydro-1,3-thiazin-4-ones 1 give the corresponding 2,4-diones 2 in good yields on oxidation with dichromate in acid medium.
    Notes: Die leicht zugänglichen 2-Thioxo-tetrahydro-1,3-thiazin-4-one 1 ergeben bei der Oxidation mit Dichromat in saurer Lösung mit guten Ausbeuten die entsprechenden 2,4-Dione 2.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/jlac.197419741108
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    Metallsubstituierte Carbene und C-metallierte Diazoalkane, VI1) α-Diazo-β-hydroxy-carbonsäureester und -ketone aus Carbonyl- und Diazolithioverbindungen sowie ihre Umlagerung zu β-Ketocarbonsäureestern und β-Diketonen (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1767-1783 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Metal-substituted Carbenes and C-metalated Diazoalkanes, VI1). - α-Diazo-β-hydroxy-carboxylates and -ketones from Carbonyl and Diazo Lithio Compounds and their Rearrangement into β-Ketocarboxylates and β-DiketonesEthyl diazoacetate (1a) can be metalated with butyllithium in tetrahydrofuran at -65°C to -110°C to give ethyl diazolithioacetate (2a), which reacts with the carbonyl compounds 3 to give (after hydrolysis) the α-diazo-β-hydroxycarboxylates 4. These can also be obtained more conveniently, by in situ reaction of 1a and 3 with butyllithium (-65°C, tetrahydrofuran). On treatment with hydrogen chloride the compounds 4 rearrange (with loss of nitrogen) to the β-ketocarboxylates 19. In the case of cycloalkanones this sequence represents a ring enlargement. - The α-diazo-β-hydroxyketones 5-8 are formed when a mixture of the carbonyl compounds 3 and the diazoketones 1b-e is treated (in tetrahydrofuran, -65°C) with lithium diisopropylamide. Butyllithium is not suitable as metalating reagent. As in the case of compounds 5, on treatment with acids α-diazo-β-hydroxyketones suffer partial rearrangement to β-diketones (with loss of nitrogen) and partial retro-aldol reaction to 3 and diazoketones.
    Notes: Diazoessigsäure-äthylester (1a) ist mit Butyllithium bei - 65 bis - 110°C (in Tetrahydrofuran) in Diazolithioessigsäure-äthylester (2a) umwandelbar, welcher mit den Carbonylverbindungen 3 die α-Diazo-β-hydroxycarbonsäureester 4 liefert. Diese sind auch in situ aus 1 a und 3 mit Butyllithium zugänglich. Sie lassen sich protonenkatalysiert in die β-Ketocarbonsäureester 19 umlagern. Bei Cycloalkanonen entspricht dies einer Ringerweiterung. - Aus den Diazoketonen 1b-e erhält man die α-Diazo-β-hydroxyketone 5-8, indem man sie bei ca. -70°C im Gemisch mit den Carbonylverbindungen 3 mit Lithiumdiisopropylamid umsetzt. Butyllithium ist hier als Metallierungsmittel ungeeignet. Wie sich mit den Verbindungen 5 ergab, werden α-Diazo-β-hydroxyketone protonenkatalysiert in unterschiedlichem Ausmaß zu ß-Diketonen umgelagert oder in einer Retroaldolreaktion zu Carbonylverbindungen 3 und Diazoketonen gespalten.
    Additional Material: 4 Tab.
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    URL: http://dx.doi.org/10.1002/jlac.197419741106
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    Elektronen- und ESR-spektroskopische Charakterisierung von dihydropteridinanalogen Pyrimido[4,5-b][1,4]thiazinderivaten und ihren Radikalkationen (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1793-1801 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Characterization of Dihydropteridine-Analogous Pyrimido[4,5-b][1,4]thiazine Derivatives and their Cation Radicals by Electronic and ESR SpectraThe 1H-NMR (fig. 1), electronic (fig. 2), and ESR spectra (fig. 3) of pyrimido[4,5-b][1,4]-thiazine derivatives 2 and of their radical cations 4 have been recorded. The existence of the 7H-tautomer is proved by comparison with corresponding known dihydropteridine derivatives 1. H/D exchange is found to occur only very slowly in the 7,8-dihydropteridin analog 2A, but rapidly in the corresponding cation radicals 4, generated by oxidation of 2 with dibenzoyl peroxide in CF3CO2R/benzene (R — H or D). Analysis of the hyperfine structure of 4, and comparison with ESR data for monohydropteridine cation radicals suggest that replacement of -N(R)- (position 8) by -S- does not essentially affect the steric and electronic properties of pteridine nuclei and may, therefore, lead to relevant antimetabolites.
    Notes: Es werden 1H-NMR-Spektren (Abb. 1), Elektronenspektren (Abb. 2) und ESR-Spektren (Abb. 3) der Pyrimido[4,5-b][1,4]thiazinderivate 2 und ihrer Radikalkationen 4 aufgenommen. Durch Vergleich mit entsprechenden, bekannten Dihydropteridinderivaten 1 wird das Vorliegen der 7H-Tautomoron nachgewiesen. Ein H/D-Austausch erfolgt beim 7,8-Dihydropteridinanalogon 2A nur sehr langsam, dagegen wird bei den entsprechenden Radikalkationen 4 ein rascher Austausch gefunden. Die Darstellung von 4 gelingt durch Oxidation der Verbindungen 2 mit Dibenzoylperoxid in CF3CO2R/Benzol (R — H oder D). Die Analyse der ESR-Hyperfeinstruktur von 4 und der Vergleich mit den ESR-Daten von entsprechenden Monohydropteridinradikalkationen zeigt, daβ der Austausch von -N(R)- (Position 8) durch - S - die elektronischen und sterischen Eigenschaften des Pteridinsystems nicht wesentlich ändert, so daß eine Antimetabolitenaktivität dieser Substanzen zu erwarten ist.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/jlac.197419741109
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    Synthese und Struktur von 3-IsochinolinolenHerrn Professor Dr. H. Bredereck in Dankbarkeit und Verehrung zum 70. Geburtstag gewidmet. (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1802-1815 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Structure of 3-Isoquinolinols**)1-Halogeno-3-isoquinolinols 2-4 are prepared by cyclization of (2-cyanophenyl)acetyl chlorides 1 in presence of anhydrous hydrogen halides. Catalytic hydrogenation gives the 3-isoquinolinols 8. The lactam-lactim tautomerism of these compounds is discussed.
    Notes: (2-Cyanphenyl)acetylchloride 1 cyclisieren in Gegenwart wasserfreier Halogenwasserstoffsäuren zu I-Halogen-3-isochinolinolen 2-4. Durch katalytische Hydrierung erhält man aus diesen die 3-Isochinolinole 8. Die Lactam-Lactim-Tautomerie dieser Verbindungsklassen wird untersucht.
    Additional Material: 10 Tab.
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  • 41
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    Synthese von N-substituierten Aminosulfonsäuren, III1) (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1816-1819 
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    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of N-Substituted Amino Sulfonic Acids, III1)The synthesis of N-substituted 4-aminobutane-1-sulfonic acids and 3-aminopropane-1-sulfonic acids by the reaction of 1,4-butanesultone and 1,3-propanesultone with primary amines is described.
    Notes: Die Darstellung der N-substituierten 4-Aminobutan-1-sulfonsäuren und 3-Aminopropan-1-sulfonsäuren durch Reaktion von 1,4-Butansulton und 1,3-Propansulton mit primären Aminen wird beschrieben.
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    URL: http://dx.doi.org/10.1002/jlac.197419741111
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    Allylmetall-Verbindungen, 1 (-)- und (+)-π-Pinenylnickelhalogenide sowie (-)- und (+)-Bis(π-pinenyl)nickel - Molekül- und Kristallstruktur von (+)-Bis(π-pinenyl)nickel (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1820-1830 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Allyl Metal-Compounds, I. - (-)- and (+)-π-Pinenylnickel Halides and (-)- and (+)-Bis(π- pinenyl)nickel - Molecular and Crystal Structure of (+)-Bis(π-pinenyl)nickelThe title compounds have been prepared by three and five stage syntheses starting from (-)-(1S,5S)-β-pinene and (+)-(1R,5R)-α-pinene, respectively. The halides may be used to separate racemic mixtures of chiral phosphines. The structure of (+)-bis(π-pinenyl)nickel has been determined by a three dimensional X-ray analysis.
    Notes: Ausgehend von (-)-(1S,5S)-β-Pinen und von (+)-(1R,5R)-α-Pinen gewinnt man in 3- bzw. 5 stufigen Synthesen die im Titel genannten Nickelkomplexe. Die Halogenide eignen sich zur Racemattrennung chiraler Phosphine. Die Struktur des (+)-Bis(π-pinenyl)nickels ergibt sich aus einer dreidimensionalen Röntgenstrukturanalyse.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/jlac.197419741112
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    Borverbindungen XXVIII1) 1,2-(2,2′-Biphenylylen)diborane(6) (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1843-1850 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Boron Compounds XXVIII1). - 1,2-(2,2′-Biphenylylene)diboranes(6)1,2-(2,2′-Biphenylylene)-1,2-diethyldiborane(6) (1) is obtained in ca. 80% yield from (2-biphenylyl)diethylborane and ethyldiborane(6)** ). 1,2-(2,2′-Biphenylylene)diborane(6) (2) and 1,2:1,2-bis(2,2′-biphenylylene)diborane(6) ( 3) are prepared in high yields by reaction of 1 with diborane and diethyl ether-trifluoroborane, respectively. Reaction of 1 with tertbutyl alcohol yields the colourless 9-tert-butyloxy-9-borafluorene and trichloroborane reacts with 1 to form the yellow 9-chloro-9-borafluorene.
    Notes: 1,2-Diäthyl-1,2-(2,2′-biphenylylen)diboran(6) (1) erhält man aus Diäthyl(2-biphenylyl)boran und Äthyldiboran(6)**) in ca. 80proz. Ausbeute. Aus 1 lassen sich mit Diboran 1,2-(2,2′-Biphenylylen)diboran(6) (2) und mit Diäthyläther-trifluorboran 1,2: 1,2-Bis(2,2′-biphenylylen)-diboran(6) (3) in guten Ausbeuten gewinnen. Mit tert.-Butylalkohol reagiert 1 zum farblosen 9-tert.-Butoxy-9-borafluoren und mit Trichlorboran zum gelben 9-Chlor-9-borafluoren.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/jlac.197419741114
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    Diin-Reaktion, XXIX1) Synthese von Benzo-, Furano-, Thiopheno-, Selenopheno- und Pyrrolo-benzotriazolchinonen (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1876-1881 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Diyne Reaction, XXIX1). - Synthesis of Benzo-, Furano-, Thiopheno-, Selenopheno-, and Pyrrolo-benzotriazolequinones1-Phenyl-1,2,3-triazole-4,5-dicarbaldehyde (1) reacts with phenylethynylmagnesium bromide to give a diol 2, whose oxidation leads to the o-diketo diyne derivative 3. With tris(triphenylphosphine)rhodium(I) chloride, 3 gives the Rh-complex 4. Reaction of the Rh-complex 4 with acetylenes, chalcogens and phenyl azide or nitrosobenzene affords the mono- and bis-heterocondensed benzoquinones 6-11.
    Notes: 1-Phenyl-1,2,3-triazol-4,5-dicarbaldehyd (1) ergibt mit Phenyläthinylmagnesiumbromid ein Diol 2, dessen Oxidation zum o-Diketo-diin-Derivat 3 führt. Mit Tris(triphenylphosphin)-rhodium(I)-chlorid entsteht aus 3 der Rh-Komplex 4. Die Umsetzung des Rh-Komplexes 4 mit Acetylenen, Chalkogenen und Phenylazid oder Nitrosobenzol führt zu den mono- und bis-heterokondensierten Benzochinonen 6-11.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419741119
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    Eine Uracil-Imidazolidinon-Umwandlung (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1882-1889 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A Uracil-Imidazolidinone Rearrangement4-Amino-1,3-dimethyl-5-nitrosouracil derivatives 1b, 3c- e treated with alkali give derivatives of 4,5-diimino-1,3-dimethyl-2-imidazolidinone 4 by opening of the uracil ring at C-6. In contrast, with 1,3-dimethylvioluric acid (3b) under the same conditions the uracil → imidazolidinone rearrangement is accompanied by preferential ring opening at C-2 yielding 2-hydroxyimino-N,N′-dimethylmesoxaldiamide (12).
    Notes: 4-Amino-1,3-dimethyl-5-nitrosouracilderivate 1b, 3c-e ergeben bei der Behandlung mit Alkali unter Öffnung des Uracilringes am C-6 Derivate des 4,5-Diimino-1,3-dimethyl-2-imidazolidinons 4. Bei der 1,3-Dimethylviolursäure (3b) erfolgt dagegen unter gleichen Bedingungen neben der Uracil → Imidazolidinon-Umwandlung bevorzugt eine Ringöffnung am C-2, wobei 2-Hydroxyimino-N,N′-dimethylmesoxaldiamid (12) entsteht.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419741120
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    Photosensibilisierte Addition von Acetonitril an Norbornen (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1890-1894 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photosensitized Addition of Acetonitrile to NorborneneAcetonitrile and ethyl acetate are added to norbornene to yield the corresponding 2-exo-norbornane derivatives 3 by a photosensitized reaction involving sensitizers such as acetophenone or benzene with triplett energies higher than 72 kcal/mol. These reactions, in contrast to other photo-initiated free radical additions to olefins, involve the triplet olefin (norbornene) as reactive intermediate.
    Notes: Acetonitril und Essigsäure-äthylester lassen sich durch photosensibilisierte Addition mittels Sensibilisatoren wie Acetophenon oder Benzol mit Triplettenergien von mindestens 72 kcal/mol in guten Ausbeuten an Norbornen zu den entsprechenden 2-exo-Norbornanderivaten 3 addieren. Im Gegensatz zu anderen photoinduzierten Additionen an ungesättigte Kohlenwasserstoffe erfolgen die untersuchten Reaktionen über den Triplettzustand des Olefins (Norbornen).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419741121
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    Enoläther, XII1) Reaktionen von Cyclopropylolefinen und Enoläthern mit organischen Aziden (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1895-1907 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Enol Ethers, XII1). - Reactions of Cyclopropylolefins and Enol Ethers with Organic AzidesΔ1-Triazolines 3 are formed from cyclopropylolefins 2 and p-nitrophenylazide (1a). Enol ethers 4 react with 1a at 50°C to yield either Δ1-triazolines 3d-f and/or N-(p-nitrophenyl)-imidic esters 5a-i, while reaction with tosyl azide(1b) at room temperature affords N-tosylimidic esters 6. - Reaction of 4 with 1 primarily yields Δ1-triazolines 3; the secondary reactions of 3 are discussed in terms of substituent effects and reaction conditions. Elimination of N2 from 3 may proceed via the zwitterion I. This reaction becomes easier the better the resulting carbocation II is stabilized.
    Notes: Cyclopropylolefine 2 bilden mit p-Nitrophenylazid (1a) in der Hitze Δ1-Triazoline 3. Enoläther 4 reagieren mit 1a bei 50°C in Abhängigkeit von ihrer Struktur und der Reaktionszeit zu Δ1-Triazolinen 3d-f und/oder N-(p-Nitrophenyl)imidsäureestern 5d-i, während mit Tosylazid (1b) bereits bei Raumtemperatur N-Tosylimidsäureester 6 entstehen. - Die Umsetzung von 4 mit 1 über primär entstehende 1-Triazoline 3 und deren Folgereaktionen wird in Abhängigkeit von Substituenten und Reaktionsbedingungen diskutiert. Die Weiterreaktion von 3 kann über das Zwitterion I erfolgen, wobei N2 um so leichter abgespalten wird, je besser das hierbei entstehende Carbokation II stabilisiert ist.
    Additional Material: 6 Tab.
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    URL: http://dx.doi.org/10.1002/jlac.197419741122
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    Reaktionsprodukte aus 3,5-Octadiin-2,7-diolHerrn Prof. Dr. H. Hellmann zum 60. Geburtstag gewidmet. (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1908-1914 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reaction Products from 3,5-Octadiyne-2,7-diol**)The hydrolysis of 5-(3-bromo-2-propynylidene)-4-methyl-1,3-dioxolane (5) leads to 5-bromomethyl-2-methyl-2,3-dihydrofuran-3-one (6) as main product and to 2-bromo-2-hexene-4,5-dione (12) as by-product. A pathway for the generation of 12 is proposed. The isomeric isoxazoles 16 and 20 are prepared from 12 and its dimethylamino derivative 13. Quaternization of normuscarine and epi-normuscarine affords muscarine chloride and epi-muscarine chloride, respectively.
    Notes: Es werden einige bei der Muscarinsynthese anfallende Nebenprodukte näher untersucht. Für die Bildungsweise von 2-Brom-2-hexen-4,5-dion (12), das bei der Hydrolyse von 5-(3-Brom-2-propinyliden)-4-methyl-1,3-dioxolan (5) neben 5-Brommethyl-2-methyl-2,3-dihydrofuran-3-on (6) entsteht, wird ein Reaktionsschema angegeben. Aus 12 und dessen Folgeprodukt 13 werden die isomeren Isoxazole 16 und 20 dargestellt. Durch Quaternierung von Normuscarin und epi-Normuscarin werden Muscarinchlorid und epi-Muscarinchlorid erhalten.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419741123
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    Masthead (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974) 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419740101
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  • 50
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    Zur ambivalenten Reaktivität des O-Acetylsalicylsäurechlorids (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 15-23 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Ambivalent Reactivity of O-Acetylsalicyloyl ChlorideIn accordance with results of Russian authors 1) an ambivalent reactivity of U-acetylsalicyloyl chloride (1) with nucleophilic partners was observed. The existence of the ring tautomer 6 was proven by its precipitation as hexachloroantimonate 11. In several reactions of 1 with nucleophilic partners cyclic products 13 were isolated when proper reaction conditions were chosen.
    Notes: In Übereinstimmung mit Ergebnissen russischer Autoren 1) wurde eine ambivalente Reaktivität des U-Acetylsalicylsäurechlorids (1) mit nucleophilen Partnern festgestellt. Es gelang erstmals, die cyclische Zwischenstufe 6 als Hexachloroantimonat 11 zu fassen. In zahlreichen Fällen konnten, bei Wahl geeigneter Reaktionsbedingungen, cyclische Produkte 13 isoliert werden.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/jlac.197419740104
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    Partielle Veresterung des α-Methyl-D-glucopyranosids mit N-(Tri-O-methylgalloyl)imidazol1) (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 4-14 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Partial Esterification of α-Methyl-D-glucopyranoside with N-(Tri-O-methylgalloyl)imidazole1)Reaction of corresponding quantities of N-(tri-O-methylgalloyl)imidazole with α-methyl-D-glucopyranoside affords α-methyl-6- (1), α-methyl-2,6-bis- (2), and α-methyl-2,3,6-tris(tri-O-methylgalloyl)-D-glucopyranoside (3). With the same N-acylimidazole both α-methyl-2-(tri-O-methylgalloyl)-6-(O-trityl)- (5) and α-methyl-2,3-bis(tri-O-methylgalloyl)-6-(O-trityl)-D-glucopyranoside (6) can be obtained from α-methyl-6-(O-trityl)-D-glucopyranoside (4). Cleavage of the trityl groups from 5 and 6 yields α-methyl-2-(tri-O-methylgalloyl)- (7) and α-methyl-2,3-bis(tri-O-methylgalloyl)-D-glucopyranoxide (8). This selective acylation is caused by intramolecular hydrogen bonds. - The compounds 1,2,3,7, and 8 were investigated by NMR spectroscopy. For the purpose of further structural determinations they were first methylated to give compounds 9, 10, 11, 12, and 13; subsequent cleavage of the acyl groups afforded the compounds 14-18. The latter compounds 14-18 and their silylation products 19-23 were investigated by mass spectrometry.
    Notes: Bei Einwirkung entsprechender Mengen N-(Tri-O-methylgalloyl)imidazol auf α-Methyl-D-glucopyranosid entstanden α-Methyl-6- (1), α-Methyl-2,6-bis- (2) und α-Methyl-2,3,6-tris-(tri-O-methylgalloyl)-D-glucopyranosid (3). Aus α-Methyl-6-(O-trityl)-D-glucopyranosid (4) wurden mit diesem Acylierungsmittel α-Methyl-2-(tri-O-methylgalloyl)-6-(O-trityl)- (5) und α-Methyl-2,3-bis(tri-O-methylgalloyl)-6-(O-trityl)-D-glucopyranosid (6) erhalten. Nach Abspaltung der Tritylgruppen ergaben 5 und 6 α-Methyl-2-(tri-O-methylgalloyl)- (7) und α-Methyl-2,3-bis(tri-O-methylgalloyl)-D-glucopyranosid (8). Diese selektive Acylierung ist auf das Auftreten von intramolekularen Wasserstoffbrücken zurückzuführen. - Die Verbindungen 1, 2, 3, 7 und 8 wurden NMR-spektroskopisch untersucht; ihre weitere Strukturbestimmung erfolgte durch Methylierung zu 9, 10, 11, 12 und 13 und anschließende Abspaltung der Acylgruppen. Von den dabei entstandenen Verbindungen 14-18 sowie deren Silylierungsprodukten 19-23 wurden die Massenspektren aufgenommen.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/jlac.197419740103
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    Über Antamanid, XVII1) Synthese weiterer antitoxisch wirksamer und unwirksamer Antamanid-Varianten (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 24-36 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Antamanide, XVII1). - Synthesis of Additional Antitoxically Effective and Ineffective Antamanide-VariantsInterchange of phenylalanine no. 6 and proline no. 7, or replacement of proline no. 7 by glycine, or omission of one of the prolines no. 7 or 8 in antamanide (1) leads respectively to the variants 2, 3 and 4, which are antitoxically ineffective. Apparently the sequence of two prolines in positions 7 and 8 is prerequisite for the biologically active conformation of the cyclodeca- peptide. Incorporation of glutamic acid into position 1 of 1 produces an analogue 12 having a protective dose (PD) of 2.5 mg/kg against 5 mg phalloidin (white mouse), which is 20% of the PD of 1 (0.5 mg). The formal product of carboxylation of 12, the α-aminobutyric acid (Abu1) analogue, has an identical PD (2.5 mg). Asp4-antamanide, an antamanide (1) likewise formally carboxylated at its alanine side chain, has the same PD (0.5 mg) as 1. Its L-retro-isomer, Asp1-Val4-antamanide (16) has a PD 〉 5 mg. Carboxymethylated Tyr6-L-retroantamanide (22) affords protection at a dose of about 10 mg/kg, which would suggest that also L-retro-antamanide, which cannot be tested exactly because of its insolubility, has a virtual PD of about the same order. This value is higher than that of a D-retroantamanide, which has also been solubilized by introduction of an ionizing group (2.5 mg). The mirror image of 1, D-antamanide (19), has a PD of the order of 10 mg. The differences in protective activities can be explained in terms of the degree of fit of the different molecules at a hypothetical receptor in the membrane of the liver cell using three sites.
    Notes: Vertauscht man im Antamanid (1) Phenylalanin Nr. 6 mit Prolin Nr. 7 oder ersetzt man Prolin Nr. 7 durch Glycin oder läßt man eines der Proline Nr. 7 oder 8 weg, so erhält man die antitoxisch unwirksamen Varianten 2, 3 und 4. Die beiden Proline in Stellung 7 und 8 sind offenbar für die richtige Molekülform des wirksamen Cyclodecapeptids entscheidend wichtig. Einbau von Glutaminsäure in Stellung 1 von 1 gibt ein Analoges 12 mit einer protektiven Dosis (PD) von 2.5 mg/kg (weiße Maus) gegen 5mg Phalloidin (PD Antamanid = 0.5 mg), was der PD des Analogen mit α-Aminobuttersäure in Stellung 1 entspricht. 12 kann als ω-carboxyliertes Abul1)-antamanid aufgefaßt werden. Das ebenso formal im Alanin Nr. 4 carboxylierte 1, Asp4-antamanid (13) besitzt mit 0.5 mg dieselbe PD wie 1. Sein L-retro-Isomeres Asp1-Val4-antamanid (16) wirkt mit einer PD ab 5 mg. Weil sich die biologische Wirksamkeit der L-retro-Form von 1, Ala1-Val4-antamanid wegen seiner extremen Schwerlöslichkeit nicht genau bestimmen läßt, wurde die Tyr6-Variante 20 synthetisiert und durch Carboxymethylierung als Salz von 22 wasserlöslich gemacht. Die PD dieses Derivats (10 mg/kg) ist höher als die früher von einem wasserlöslich gemachten Derivat des D-retro-Antamanids erhaltene PD von 2.5 mg. Der optische Antipode von 1, D-Antamanid (19) zeigt mit PD = 10 mg nur ca. 5 % der Wirksamkeit von 1. Die Abstufung der protektiven Wirkungen läßt sich aus dem mehr oder weniger guten Anpassen des Moleküls an einen hypothetischen Rezeptor der Leberzellmembran mit Hilfe von 3 Kontaktstellen verstehen.
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    URL: http://dx.doi.org/10.1002/jlac.197419740105
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    Borverbindungen, XXIV1) Katalysierte Hydrolyse von Trialkylboranen (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 54-68 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Boron Compounds, XXIV1). - Catalysed Hydrolysis of TrialkylboranesThe trialkylboranes 1 and the boron heterocyclic compounds 9-ethyl-9-borabicyclo[3.3.1]-nonane 4 and cis,cis,trans-perhydro-9b-boraphenalene 7a react with water in the presence of pivalic acid derivatives [e. g. diethylboryl pivalate, ethylene dipivalate] smoothly and quantitatively at room temperature with cleavage of one B—CAryl bond of 1-ethyl-3-methyl-1-boraindan 9 is cleaved slowly but selectively to 10 at room temperature even without catalyst. The hydrolysis and especially the deuterolysis of 9 are accelerated when diethylboryl pivalate is present. - The tetraalkyldiboranes 2a-d are easily obtained in high yield from trialkylboranes 1a-d in the presence of catalyst. The dialkylhydroxyboranes 3a and b can also be prepared in this way. Analogously the boron heterocycles 4 and 7a yield mixtures of diboroxanes; 4 yields 5a and b (oxidation of which yields 6a or b respectively),and 7a affords 8. Only compound 9 yields an uniform diboroxane 10. - The six-membered cyclic arrangements of atoms probably occurring in the catalysed protolysis are compared with those which may be involed in the anhydride and borane dismutations of several diethylboryl carboxylates. Diethylboryl pivalate 11 yields triethylborane and B,B′-diethyl(oxydiboryl) dipivalte 12 and it also reacts with pivalic acid giving 12 and it also reacts with pivalic acid giving 12 and B,B′-(bispivaloyloxy)(oxydiboryl) dipivalate 13.
    Notes: Die Trialkylborane 1 und die Boretherocyclen 9-Äthyl-9-borabicyclo[3.3.1]nonan (4), cis,cis,trans-Perhydro-9b-boraphenalen (7a) reagieren bei Raumtemperatur mit Wasser nach Zusatz kleiner Mengen von Pivalinsäurederivaten ( z.B. Diäthylboryl-pivalat, Äthylen-di-pivalat) glatt und quantitativ unter Spaltung einer B C-Bindung. Die B CArylBindung des 1-Äthyl-3-methyl-1-boraindans (9) wird bei Raumtemperatur selektiv bereits ohne Katalysator langsam zu 10 gespalten. Hydrolyse und vor allem Deuterolyse von 9 lassen sich durch Diäthylboryl-pivalat beschleunigen. - Die aus den Trialkylboranen 1a-d entstehenden Tetraalkyldiborane 2a-d sind leicht in hohen Ausbeuten zu gewinnen. Auch die Dialkylhydroxyborane 3a und b sind so zugänglich. Die Borheterocyclen 4 und 7a liefern entsprechend Gemische von Diboroxanen; aus 4 erhält man 5a und b (daraus nach Oxidation 6a bzw. b) sowie 8 aus 7a. Nur 9 liefert ein einheitliches Diboroxan 10. - Die während der katalysierten Protolyse möglichen cyclischen Atomanordnungen werden mit denen der Anhydrid- und Boran-Dismutationen von Diäthylboryl-carboxylaten verglichen. Diäthylboryl-pivalat 11 liefert bei der Pyrolyse Triäthylboran und B,B′-Diäthyl(oxydiboryl)-dipivalat 12 sowie mit Pivalinsäure 12 und B,B′-(Bispivaloyloxy)(oxydiboryl)-dipivalat 13.
    Additional Material: 2 Tab.
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    Masthead (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974) 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419740201
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    Über die gemeinsame Einwirkung von elementarem Schwefel und gasförmigem Ammoniak auf Ketone, LXXXIV1) Hydrazinolyse von 3-Imidazolin-5-thionen zu 1,2-Dihydro- und 1,2,3,4-Tetrahydro-S-tetrazinen (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 157-167 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Joint Action of Elemental Sulfur and Gaseous Ammonia on Ketones, LXXIV1). -Hydrazinolysis of 3-Imidazoline-5-thiones to 1,2-Dihydro- and 1,2,3,4-Tetrahydro-S-tetrazines1,2-Dihydro-S-tetrazines 2 and 1,2,3,4-tetrahydroStetrazines 3 are synthesized by reacting 3-imidazoline-5-thiones 1 with hydrazine hydrate in ethanol. Compounds 3 are also obtained from α-oxothioamides 4 by condensation with ketones and hydrazine hydrate. With3 acetone gives the condensation products 5. - 3-Imidazoline-5-thiones lh, m, and o having bulky groups react with hydrazine hydrate to give the 4-hydrazino-2H-imidazoles 6. 3-Imidazolin-5-ones 7 are cleaved by hydrazine hydrate to α-hydrazonoamides 9; no reaction with 4-methylthio-2H-imidazoles 8 was observed.
    Notes: 1,2-Dihydro-S-tetrazine 2 und 1,2,3,4-Tetrahydro-S-tetrazine 3 bilden sich durch Umsetzung von 3-Imidazolin-5-thionen 1 mit Hydrazin-hydrat in Äthanol. Die Verbindungen 3 erhält man auch durch Kondensation von α-Oxothioamiden 4 mit Ketonen und Hydrazin-hydrat. Mit Aceton reagiert 3 zu den Kondensationsprodukten 5. - 3-Imidazolin-5-,thione 1h, m und o mit sperrigen Substituenten setzen sich mit Hydrazin-hydrat zu 4-Hydrazino-2H-imidazolen 6 um. 3-Imidazolin-5-one 7 werden durch Hydrazin-hydrat zu α-Hydrazono-amiden 9 gespalten, während 4-Methylthio-2H-imidazole 8 nicht reagieren.
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    Reaktionen mit Phenylaminoaluminium, III1 Umsetzung von (N-Alkylphenylamino)aluminium mit Aldiminen (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 183-188 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Phenylaminoaluminium, III1). - Reactions of (N-Alkylphenylamino)aluminiums with AldiminesIt is shown that, like dialkyl(N,N-diphenylamino)aluminiums 1, the (N-alkylphenylamino)-aluminiums of type 2 react with aldimines by addition of the C—N group to the ortho-H of the phenylamino group. The N-benzhydrylidenanilines 4 (Table 1) are formed, which now are easily preparable in yields of up to 65%.
    Notes: Es wird gezeigt, daß analog den Dialkyl(N,N-diphenylamino)aluminium 1 auch (N-Alkyl-phenylamino)aluminium des Typs 2 mit Aldiminen durch Anlagerung der C=N-Gruppe an den ortho-Wasserstoff der Phenylaminogruppe reagieren. Dabei entstehen die N-Benzhydrylidenaniline 4 (Tabelle l), die somit in Ausbeuten bis 65% leicht zugänglich werden.
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    URL: http://dx.doi.org/10.1002/jlac.197419740204
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    Synthese monomerer cyclischer Cystinpeptide, II Synthese der Sequenz A 10-21 des Schafinsulins als monomeres, cyclisches, unsymmetrisches Cystinpeptidderivat1) (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 283-289 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of Monomeric Cyclic Cystine Peptides, II. - Synthesis of the Sequence A 10-21 of Ovine Insulin as Monomeric, Cyclic, Asymmetric Cystine Peptide Derivative1)The completely protected cysteine peptide, Trt-Val-Cys(Trt)-Ser(But)-Leu-Tyr(But)-Gln-Leu-Glu(OBut)-Asn-Tyr(But)-Cys(Trt)-Asn-OBut (13), which corresponds to the amino acid series of sequence A 10-21 of the ovine insulin A-chain, was synthesized by fragment condensations. The product was then converted by treatment with iodine in methanol into the corresponding cystine peptide derivative 14 in the N-terminal free form.
    Notes: Das vollständig geschützte Cysteinpeptid Trt-Val-Cys(Trt)-Ser(But)-Leu-Tyr(But)-Gln-Leu-Glu(OBut)-Asn-Tyr(But)-Cys(Trt)-Asn-OBut (13), dessen Aminosäurefolge der Sequenz A 10-21 der Schafinsulin-A-Kette entspricht, wurde durch Fragmentkondensationen aufgebaut und durch Behandlung mit Jod in Methanol in das entsprechende Cystinpeptidderivat 14 in N-terminal freier Form übergeführt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419740214
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    Notiz über die Darstellung des 3,6-Diaminoxanthyliumkations (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 334-335 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Note on the Preparation of the 3,6-Diaminoxanthylium CationThe hitherto undescribed 3,6-diaminoxanthylium cation can be prepared easily in a one-step reaction from 3-aminophenol and formaldehyde in concentrated sulfuric acid.
    Notes: Das bisher nicht beschriebene 3,6-Diarninoxanthyliumkation läßt sich leicht in einer einstufigen Reaktion aus 3-Aminophenol und Formaldehyd in konzentrierter Schwefelsäure gewinnen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419740218
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  • 59
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    Cyclische Imidsäureester aus Nitrilen und AminoalkoholenHerrn Prof. Dr. H. Hellmann zum 60. Geburtstag gewidmet. (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 996-1009 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Formation of Cyclic Imidic Esters by Reaction of Nitriles with Amino Alcohols**)The 2-oxazolines 4 and 7 and the 4H-5,6-dihydro-1,3-oxazines 5 and 8 were prepared by reaction of the nitriles 1 and 6 with amino alcohols 2 and 3 in the presence of catalytic amounts of certain metal salts. 2-Aminoalkyl-2-oxazolines 13 and 15, which have been prepared analogously, cleave at 190-230°C to give 2-alkenyl-2-oxazolines 14.
    Notes: Durch Umsetzung der Nitrile 1 und 6 mit den Aminoalkoholen 2 und 3 in Gegenwart von katalytisch wirkenden Metallsalzen wurden die 2-Oxazoline 4 und 7 sowie die 4H-5,6-Dihydro- 1,3-oxazine 5 und 8 erhalten. Analog dargestellte 2-Aminoalkyl-2-oxazoline 13 und 15 wurden bei 190-230°C zu den 2-Alkenyl-2-oxazolinen 14 gespalten.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419740615
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  • 60
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    Metallkomplexe mit Tetrapyrrol-Liganden, X1) Synthese und Konfiguration weiterer (α,γ-Dimethyl-α,γ-dihydrooctaäthylporphinato)metallkomplexe (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1046-1062 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Metal Complexes with Tetrapyrrole Ligands, X1). - Synthesis and Configuration of Further (a,y-Dimethyl-a,y-dydrooctaethy1porphinato)metal ComplexesStarting from metal complexes 1a, 1f-1m of octaethylporphin [(OEP)MXY (M = Zn, Pd, Pt, Ga, In, Mn, Ti, V, Si)] another series of (a,y-dimethyl-a,y-dihydrooctaethylporphinat0)- metal complexes 2f-2n [(OEPMe2)MXY (M = Pd, Pt, Ga, In, Mn, Ti, V, Si, Sn)] has been prepared and spectroscopically characterized. Reductive methylation of (0EP)MXY 1f-1m yields 2f-2m. The axial ligands X and Y are substituted under the reaction conditions if ligands other than terminal oxide ligands are present. (OEPMeZ)Sn(OAc)z (2n) is formed from SnClz and (OEPMe2)Hz (3) prepared in situ. Comparison of the 1H-NMR spectra of the complexes 2a-2n demonstrates the syn-axial configuration of C-cc and C-y in (OEPMe2)MXY 2. The methyl groups and the terminal oxide ligand are syn-axial (exo) in (0EPMe2)Ti=O (2k).
    Notes: Ausgehend von Metallkomplexen 1a, 1f-1m des Octaatlylporphins [(OAP)MXY (M = Zn, Pd, Pt, Ga, In, Mn, Ti, V, Si)] wurden weitere (a,y-Dimethyl-a,y-dihydrooctaathylporphinato)metallkomplexe2f-2n [(OxPMe2)MXY (M = Pd, Pt, Ga, In, Mn, Ti, V, Si, Sn)] dargestellt und spektroskopisch charakterisiert. Die reduzierende Methylierung von (OAP)MXY 1f-1m liefert 2f-2m. Die axialen Liganden X und Y werden dabei ausgetauscht, soweit andere als terminale Oxid-Liganden vorhanden sind. (OAPMez)Sn(OAc)z (2n) entsteht aus SnC12 und in situ bereitetem (0APMez)Hz (3). Vergleich der IH-NMR-Spektren der Komplexe 2a-2n deutet auf die syn-axiale Konfiguration von C-cc und C-y in (OAPMe2)MXY 2 hin. (0APMez)Ti=O (2k) tragt die Methylgruppen und den terminalen Oxid-Liganden in syn-axialer (exo-) Position.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419740705
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  • 61
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    Synthese von 4-Hydroxynaphtho[1,2-c]- und 3-Oxoindeno-[2,3-c]isocumarinen (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1126-1131 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of 4-Hydroxynaphtho[l,2-c]- and 3-oxoindeno[2,3-c]isocoumarinsThe syntheses of naphtho- and indenoisocoumarins and the lactam derivative of the former are described. Duro and Condorelli′s method4) for the synthesis of isocoumarin-3-carboxylic acid has been extensively studied and extended to the synthesis of 4-arylisocoumarin-3-carb-oxylic acid.
    Notes: Die Synthesen von Naphtho- und Indenoisocumarinen sowie das Lactam der ersteren werden beschrieben. Die Methode von Duro und Condorelli4) zur Synthese von Isocumarin-3-carbonsäure wurde ausführlich untersucht und auf die Darstellung der 4-Arylisocumarin-3-carbonsäure angewandt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419740708
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  • 62
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    Photochemie kleiner Ringe, XXVIII1) Dibenzo[2.4]spirene und deren Umlagerungsprodukte durch Photofragmentierung und Thermolyse von Spiropyrazolen (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1132-1139 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photochemistry of Small Rings, XXVIII1). - Dibenzo[2.4]spirenes and Their Derivatives via Photofragmentation and Thermolysis of SpiropyrazolesPhotofragmentation of the spiropyrazoles 3 leads to the dibenzo[2.4]spirenes 4 in good to average yields. Thermolysis of 3 at lower temperatures also gives 4. At higher temperature, however, the pentalene derivatives 9 are formed. This rearrangement involves spirenes 4. The vinylcarbene 11 or the diradical 13 are intermediates in the reaction 3 → 4. Rearrangement 4 → 9 can proceed synchronously or via the diradical 15.
    Notes: Die Photofragmentierung der Spiropyrazole 3 ergibt in guten bis mittleren Ausbeuten die Dibenzo[2.4]spirene 4. Die Thermolyse von 3 führt bei tieferen Temperaturen ebenfalls zu 4, bei höheren Temperaturen werden die Pentalen-Derivate 9 gebildet. Bei dieser Umlagerung treten die Spirene 4 als Zwischenprodukte auf. Die Reaktion 3 → 4 dürfte über das Vinylcarben 11 oder das Diradikal 13 als Zwischenstufen verlaufen. Die Umlagerung 4 → 9 kann entweder synchron oder über ein Diradikal 15 formuliert werden.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419740709
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  • 63
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    Über die Inhaltsstoffe des grünen Knollenblätterpilzes, XLVII1) Proamanullin und Amanullinsäure sowie zwei unbekannte Derivate des β-Amanitins; die restlichen Mitglieder der Amanitinfamilie (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1587-1595 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Components of the Green Deathcap Toadstool, Amanita phalloides, XLVII1). - Proamanullin, Amanullinic Acid, and Two Unidentified Derivatives of β-Amanitin; the Residual Members of the Amanitin FamilyThe isolation and maximal characterization of some members of the amanitin family is reported on, which occur only in minimal amounts in the methanolic extract of Amanita phalloides: Proamanullin 1b, a nontoxic compound contains proline instead of hydroxy-proline in amanullin (1a). The likewise nontoxic amanullinic acid 1c is converted into 1a by reaction with ammonia via a mixed anhydride. Two neutral, toxic derivatives of β-amanitin, X-1 and X-2, are most probably not amides but rather esters. X-1 forms a complex with borate, and therefore could possibly be an ester of β-amanitin with glycerol.
    Notes: Es wird über die Isolierung und soweit wie mögliche Charakterisierung einiger in winziger Menge im Methanolextrakt von Amanita phalloides enthaltenen Vertreter der Amanitinfamilie berichtet: Proamanullin 1b, eine ungiftige Komponente, enthält anstelle des Hydroxyprolins von Amanullin (1a) ein Prolin. Amanullinsäure 1c, ebenfalls ungiftig, läßt sich über das gemischte Anhydrid mit Ammoniak in 1a verwandeln. Zwei giftige neutrale Derivate des β-Amanitins, X-1 und X-2, sind sehr wahrscheinlich keine Amide, sondern Ester. X-1 bildet mit Borat einen Komplex; es könnte ein Glycerinester sein.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419741007
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  • 64
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    Heterocyclische Siebenring-Verbindungen, XII1) Synthese 3,5-substituierter 4-Phenyl-1-benzoxepine über 2,3-Dihydro-Vorstufen (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1301-1314 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Heterocyclic Seven-membered Ring Compounds XII1). - Synthesis of 3,5-Substituted 4-Phenyl-1-benzoxepins via 2,3-Dihydro PrimersThe 4-phenyl-2,3-dihydro-1-benzoxepin-3-ones 7 and 13 have been alkylated or acetylated to the 1-benzoxepins 8, 10, 17, and 19; synthesis of 16 was achieved by dehydrobromination of 15.
    Notes: Die 4-Phenyl-2,3-dihydro-1-benzoxepin-3-one 7 und 13 wurden zu den 1-Benzoxepinen 8, 10, 17 und 19 alkyliert oder acetyliert. Die Synthese von 16 gelang durch Bromwasserstoffabspaltung aus 15.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419740817
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  • 65
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    Electronic Resource
    Kondensationen mit Methylendisulfonen (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1315-1321 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Condensations with Methylene DisulfonesThe condensation between methylene bis(phenyl sulfone) (1a) and aldehydes takes place without rearrangement of a sulfonyl group. This is demonstrated by catalytic hydrogenation to the alkylidene bis(phenyl sulfones) 8. An independent synthesis for 8 is presented. Condensation of 1a with formaldehyde, on the other hand, gives the rearranged vinylene disulfone 12. - The methylene disulfones 1 are converted directly and in good yields to the Mannich bases 13 and 14, from which vinylidene disulfones 15 are obtainable.
    Notes: Bei der Kondensation von Methylenbis(phenylsulfon) (1a) mit Aldehyden erfolgt keine Umlagerung eines Sulfonrestes; das wird durch katalytische Hydrierung zu den Alkyliden-bis(phenylsulfonen) 8 und deren unabhängige Synthese gezeigt. Die Kondensation von 1a mit Formaldehyd führt dagegen zum umgelagerten Vinylendisulfon 12. - Erstmals sind die Mannich-Basen 13 und 14 von den Methylendisulfonen 1 direkt und in guten Ausbeuten hergestellt und daraus die Vinylidendisulfone 15 leicht zugänglich gemacht worden.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419740818
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  • 66
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    Über Verbindungen mit Urotropin-Struktur, LIV1) 2,2-Bis(chlormethyl)acetophenon als neues α,α′-Anellierungsreagenz (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1322-1327 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Compounds with Urotropine Structure, LIV1). - 2,2-Bis(chloromethyl)acetophenone as a New α,α′-Annelation ReagentThe α,α′-annelation of 2,2-bis(chloromethyl)acetophenone (2) to the enamines formed by reaction of cyclic ketones 1a-e with pyrrolidine affords the corresponding 3-benzoyl-substituted bicyclic compounds 4a-e. 3-Benzoylbicyclo[3.3.1]nonan-9-(one ethylene acetal) (5a) is oxidized to give 3-oxobicyclo[3.3.1]nonan-9-(one ethylene acetal) (6a). A new synthesis of the adamantane system has been found which involves carbene insertion and use of 3-benzoyl-7,7-dimethylbicyclo[3.3.1]nonan-9-one (4b) as starting material.
    Notes: Die α,α′-Anellierung von 2,2-Bis(chlormethyl)acetophenon (2) an die aus Pyrrolidin und den cyclischen Ketonen 1a-e gebildeten Enamine liefert die entsprechenden 3-Benzoyl-substituierten bicyclischen Verbindungen 4a-e. Oxidative Abspaltung des Benzoylrestes führt am Beispiel des 3-Benzoylbicyclo[3.3.1]nonan-9-(onäthylenacetals) (5a) zum 3-Oxobicyclo-[3.3.1]nonan-9-(onäthylenacetal) (6a). Ausgehend vom 3-Benzoyl-7,7-dimethylbicyclo-[3.3.1]nonan-9-on (4b) wurde eine neue Synthese des Adamantansystems mit Hilfe der Carben-Einschiebungsreaktion gefunden.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419740819
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  • 67
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    Synthesen in der Thietan-Reihe, III1) 2,8-Dithiadispiro[3.1.3.1]decan und sein Sauerstoffanalogon (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1328-1332 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses in the Thietane Series, III1). - 2,8-Dithiadispiro[3.1.3.1]decane and its Oxygen AnalogueThe syntheses of the dispiro compound 2a, of the oxygen analogue 8 and of the unsymmetrical dispiro compound 11 are described. The structure of 2a is supported by the electronic spectrum and by comparison with that of the trispiro compound 5a. Hence an alternative structure 4 can be ruled out.
    Notes: Es wird eine Synthese der Dispiroverbindung 2a, des entsprechenden Sauerstoffanalogons 8 und der unsymmetrischen Dispiroverbindung 11 beschrieben. Die Struktur von 2a wird durch das Elektronenspektrum und durch dessen Vergleich mit dem der Trispiroverbindung 5a gestützt. Eine denkbare Alternative 4 kann ausgeschlossen werden.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419740820
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  • 68
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    Aromatische Diazoverbindungen, V1) Reaktion aromatischer Diazoniumsalze mit Nitritionen2) (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1333-1347 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Aromatic Diazo Compounds, V1). - Reaction of Aromatic Diazonium Salts with Nitrite Ions2)The kinetics of the reaction of m-nitrobenzenediazonium tetrafluoroborate with excess sodium nitrite in aqueous buffer solution at pH 6.5 have been investigated volumetrically. The influence of changes in concentration of diazonium salt, nitrite ion and buffer on the rate of reaction was determined. A different reaction order and slightly different rates were observed when the reactions were conducted under nitrogen instead of oxygen or air. Trapping experiments proved aryl radicals to be intermediates of the reactions. A radical chain mechanism in which N-nitro aryldiimine participates is proposed.
    Notes: Die Kinetik der Reaktion von m-Nitrobenzoldiazonium-tetrafluoroborat mit überschüssigem Natriumnitrit in wässeriger Pufferlösung bei pH 6.5 wurde in Abhängigkeit von der Konzentration an Diazoniumsalz, Nitritionen und Puffer gasvolumetrisch verfolgt. Dabei wurden unter Stickstoff eine andere Reaktionsordnung und Reaktionsgeschwindigkeit festgestellt als unter Sauerstoff oder Luft. - Arylradikale konnten durch Abfangen als Zwischenstufe nachgewiesen werden. Es wird ein Radikalkettenmechanismus vorgeschlagen, an dem N-Nitroaryldiimin beteiligt ist.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419740821
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  • 69
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    Aliphatische Azoverbindungen, IV1 Eine neue Synthese für tert.-Azoalkane (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1348-1356 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Aliphatic Azo Compounds, IV1). - A New Synthesis of tert-AzoalkanesA simple, high yield procedure for the large scale synthesis of tert-azoalkanes 3 from readily available chloroazoalkanes 2 and trialkyl- or triphenylaluminum is described. The scope of the reaction is discussed.
    Notes: Eine ergiebige, einfach und im großen Maßstab durchzuführende Synthese für tert.-Azoalkane 3 aus den gut zugänglichen Chlorazoverbindungen 2 mit Trialkyl- oder Triphenylaluminium wird beschrieben. Die Anwendungsbreite der Reaktion wird diskutiert.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419740822
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  • 70
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    Masthead (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974) 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419740901
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  • 71
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    Notiz über die elektrocyclische Ringöffnung von 2,3,4,4-Tetraphenyl-2-cyclobuten-1-on zu 2,3,4-Triphenyl-1-naphthol (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1534-1535 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Note on the Electrocyclic Ring Opening of 2,3,4,4-Tetraphenyl-2-cyclobuten-1-one to 2,3,4-Triphenyl-1-naphtholThe thermal isomerization of 2,3,4,4-tetraphenyl-2-cyclobuten-1-one to 2,3,4-triphenyl-1- naphthol via electrocyclic opening of the four-membered ring and intramolecular recyclization of the intermediary vinylketene proceeds in yields exceeding 90% both in the melt phase and in a refluxing benzene solution. The reaction is appreciably retarded in the presence of activated AlCl3 as a result of complex formation.
    Notes: Die thermische Isomerisierung von 2,3,4,4-Tetraphenyl-2-cyclobuten-1-on zu 2,3,4-Triphenyl-1-naphthol durch elektrocyclische Vierringöffnung und intramolekulare Recyclisierung des intermediären Vinylketens verläuft in Ausbeuten von über 90% sowohl in der Schmelze, als auch in siedendem Benzol. Die Reaktion wird beträchtlich verlangsamt in Gegenwart von aktiviertem AlCl3 infolge Komplexbildung.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419740917
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  • 72
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    Notiz über die Röntgenstrukturanalyse von Al,Zr-μ-Chloro-1-[bis(cyclopentadienyl)zirkonio(IV)]-2,2-bis(diäthylaluminio)äthanProf. Dr. Dr. h. c. Karl Ziegler† in Verehrung gewidmet. (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1531-1533 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Note on the X-Ray Structure Analysis of Al,Zr-μ-Chloro-1-[bis(cyclopentadienyl)zirconio(IV)]-2,2-bis(diethylaluminio)ethane**)From a single crystal X-ray structure analysis of the compound (C5H5)2Zr(Cl)(CH2CH)-[Al(C2H5)2]2 all atoms except hydrogen were located. The essential structural characteristics of the compound, which crystallizes in the orthorhombic space group P212121 are discussed. The Zr-C-C-Al-structure is confirmed.
    Notes: Durch eine Einkristall-Röntgenstrukturuntersuchung der Verbindung (C5H5)2Zr(Cl)(CH2CH)- [Al(C2H5)2]2 konnten sämtliche Atome außer Wasserstoff lokalisiert werden. Die wesentlichen Strukturmerkmale der Verbindung, die in der rhombischen Raumgruppe P212121 kristallisiert, werden diskutiert. Die Zr-C-C-Al-Struktur ist gesichert.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419740916
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  • 73
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    Berichtigung (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1541-1541 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: No Abstract
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419740919
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    Masthead (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974) 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419741001
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  • 75
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    Über die Inhaltsstoffe des grünen Knollenblätterpilzes, XLV1) Die absoluten Konfigurationen des giftigen und des ungiftigen Phalloidinsulfoxides und der Amatoxine (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1570-1579 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Components of the Green Deathcap Toadstool, Amanita phalloides, XLV1). - The Absolute Configurations of the Toxic and Nontoxic Phalloidin Sulfoxide and of the Amatoxins2ind-Ethylthio-L-tryptophan (2a) synthesized from L-tryptophan and ethyl sulfenyl chloride is oxidized by H2O2 in glacial acetic acid to give the two diastereoisomeric sulfoxides 2b and 2c, which can be separated from each other. Crystals of 2b are subjected of X-ray analysis, which reveals R-configuration at the chiral SO center. By analogy with the ORD curve of 2b having positive values between 280 and 360 nm (figure 3), the toxic phalloidin sulfoxide 1b (figure 4) can be assigned the same configuration. Since comparable amatoxins (amanin, O-acetyl-γ-amanitin) show very similar behaviour in ORD the R-configuration at the SO-center is established also in this series of toxins.
    Notes: 2ind-Äthylthio-L-tryptophan (2a) wurde aus L-Tryptophan und Äthylsulfenylchlorid synthetisiert und mit H2O2 in Eisessig zu den zwei diastereomeren Sulfoxiden 2b und 2c oxidiert, die getrennt und kristallisiert wurden. Für die Kristalle von 2b zeigt die Röntgenstrukturanalyse R-Konfiguration am chiralen So-Zentrum an. Durch den analogen Verlauf der ORD-Kurve von 2b, die zwischen 280 und 360 nm positive Werte hat (Abbildung 3), und der des giftigen Phalloidinsulfoxids 1b bestimmt. Da vergleichbare Sulfoxide de Amatoxinreihe (Amanin, O-Acetyl-γ-amanitin) ähnliche ORD-Kurven geben, ist auch deren R-Konfiguration am SO-Zentrum erwiesen.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/jlac.197419741005
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    Über die Inhaltsstoffe des grünen Knollenblätterpilzes, XLIV1) Die Konfiguration der hydroxylierten Isoleucine der AmatoxineHerrn Prof. Dr. Güter Scheibe in Verehrung zum 80. Geburtstag gewidmet. (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1561-1569 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Components of the Green Deathcap Toadstool, Amanita phalloides, XLIV1). - Configuration of the Hydroxylated Isoleucines from AmatoxinsThe absolute configuration of the γ-hydroxyisoleucine occurring in γ-amanitin has been established by X-ray structure analysis of its lactone hydrobromide as (2S,3R,RS)-2-amino-3-methyl-4-hydroxyvaleric acid (6). This structure, which is different from the 4R-configuration 2 formerly assumed2), is consistent with Hudson′s lactone rule, 1H-NMR spectroscopy (nuclear Overhauser effect), and PFT 13C-NMR analysis. Since the corresponding γ,δ-dihydroxyisoleucine of α-and β-amanitin has been converted into 6 without touching the C-4 atom, this amino acid must now be formulated as (2S,3R,4R)-2-amino-3-methyl-4-5-dihydroxyvaleric acid (8).
    Notes: Durch Röntgenstrukturanalyse seines γ-Lacton-hydrobromids wurde die absolute Konfiguration jenes γ-Hydroxyisoleucins, das im γ-Amanitin vorkommt, als (2S,3R,4S)-2-Amino-3-methyl-4-hydroxyvaleriansäure (6) bestimmt. Diese im Gegensatz zu früher2) als 4R-2 formulierte Konfiguration ist vereinbar mit der Hudsonschen Lactonregel, dem 1H-NMR-spektrum (Nuclear-Overhauser-Effect) und der PFT-13C-NMR-Analyse. Da schon früher das entsprechende γ,δ-Dihydroxyisoleucin des α-und β-Amanitins ohne Berührung von C-4 in 6 übergeführt werden konnte, muß jetzt auch die Strukturformel dieser Aminosäure zu (2S,3R,4R)-2-Amino-3-methyl-1-4,5-dihydroxyvaleriansäure (8) abgewandelt werden.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/jlac.197419741004
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  • 77
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    Über die Inhaltsstoffe des grünen Knollenblätterpilzes, XLVI1) Das zum giftigen O-Methylamanitin diastereomere ungiftige Sulfoxid (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1580-1586 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Components of the Green Deathcap Toadstool, Amanita phalloides, XLVI1). - The Nontoxic sulfoxide Diastereoisomeric to O-Methyl-α-amanitinO-Methyl-α-amanitin (1b), the toxic product of methylation of the phenolic OH group of α-amanitin is reduced by Raney-nickel to the likewise toxic O-methyl-S-deoxo-α-amanitin (thioether 1a). On oxidation with H2O2 in glacial acetic acid 1a yields, in addition to the R-Sulfoxide 1b, a diastereomeric S-sulfoxide 1c shows no toxicity in doses up to 10 mg per kg of the white mouse. exhibits only 101 of the inhibitory action of 1b on the animal RNA polymerase II, and differs from 1b in the UV-, ORD-and CD spectra. Proof of the structure ascribed to it is provided by further oxidation of 1c; this yields the toxic sulfone 1d, which is also obtained from 1b by the same reaction.
    Notes: Das an der phenolischen OH-Gruppe methylierte, giftige α-Amanitin (O-Methyl-α-amanitin, 1b) wird mit Raney-Nickel zum ebenfalls giftigen O-Methyl-S-desoxo-α-amanitin (Thioäther 1a) reduziert. Verbindung 1a gibt bei der Oxidation mit H2O2 in Eisessig außer dem ursprünglichen R-Sulfoxid 1b ein zweites diastereomeres Sulfoxid 1c, das am chiralen Schwefel S-Konformation besitzt. Verbindung 1c, ist in Dosen bis zu 10 mg pro kg weiße Maus ungiftig, zeigt bei der animalischen RNA-Polymerase II nur 101 der Hemmwirkung von 1b, und unterscheidet sich von 1b auch deutlich in den UV-, ORD- und CD-Spektren. Zum Beweis der Struktur von 1c dient die Weiteroxidation mit H2O2 in Eisessig, die das giftige Sulfon 1d liefert, das man auch durch gleichartige Oxidation von 1b erhält.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/jlac.197419741006
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    Über Mercaptoacrylsäure-Derivate, XII1) 1,4-Diradikale als Zwischenstufen der Monomerisierung von 1,2-Bis(arylthio)-1,2-cyclobutandiyldicyaniden zu α-(Arylthio)-acrylnitrilen (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1661-1670 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Derivatives of Mercaptoacrylic Acid, XII1). - 1,4-Diradicals as Intermediates of Monomerization of 1,2-Bis(arylthio)-1,2-cyclobutanediyl Dicyanides to α-(Arylthio)acrylonitrilesα-(Arylthio)acrylonitriles 4, whose preparation is described, dimerize more rapidly ot yield 1,2-bis(arylthio)-1,2-cyclobutanediyl dicyanides 6 than do α-(alkylthio)acrylonitriles to give the corresponding cyclobutane derivatives. This appears to be α-(alkylthio)acrylonitriles to give the corresponding cyclobutane derivatives. This appears to be dur to the higher mesomeric stabilization of the 1,4-diradical intermediates (e.g.9) by arylthio groups. These radicals are detected by ESR spectroscopy in the case of thermal cleavage of bis(p-methoxyphenylthio)-1,2-cyclobutanediyl dicyanides (6b).
    Notes: α-(Arylthio)acrylnitrile 4, deren Darstellung beschrieben wird, dimerisieren merklich schneller zu 1,2-Bis(arylthio)-1,2-cyclobutandiyldicyaniden 6 als α-(Alkylthio)acrylnitrile zu den entsprechenden Cyclobutan-Derivaten. Dies dürfte eine Folge der höheren Mesomeriestabilisierung der als Zwischenstufe auftretenden 1,4-Diradikale (z.B. 9) durch die Arylthiogruppen sein. ESR-spektroskopisch wurden diese Radikale im Falle der thermischen Spaltung von 1,2-Bis(pmethoxyphenylthio)-1,2-cyclobutandiyldicyanid (6b) nachgewiesen.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/jlac.197419741017
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    Lösliche Copolymere aus 1-Vinyl-2-pyrrolidinon und Vinylacetat zur Synthese von PeptidenHerrn Professor Dr. Bredereck zum 70. Geburtstag gewidmet. (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1671-1674 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Soluble Copolymers of 1-Vinyl-2-2pyrrolidinone and vinyl Acetate for the Synthesis of Peptides**)The tetrapeptide H—Ala—Gly—Leu—Ala—OH was synthesized on a soluble support consisting of a copolymer of 1-vinyl-2-pyrrolidinone and vinyl acetate which was hydrolysed in a polymeranalogous reaction. The hydroxyl groups so obtained were used as functional groups for the fixation of the first amino acid to the support. The tert-butyloxycarbonyl group was used as amino-protecting group. Coupling was carried out by the dicyclohexylcarbodiimide method. The low-molecular excesses were separated by ultrafiltration.
    Notes: An einem löslichen Träger wurde das Tetrapeptid H—Ala—Gly—Leu—Ala—OH synthetisiert. Der Träger ist ein Copolymer von 1-Vinyl-2-pyrrolidinon und Vinylacetat, das in einer polymeranalogen Umsetzung hydrolysiert wurde. Die so erhaltenen Hydroxyguppen wurden als funktionelle Gruppen zur Fixierung der ersten Aminosäure an den Träger benutzt. Als Aminoschutzgruppe wurde die tert.-Butyloxycarbonylgruppe verwendet. Die Kupplungen erfolgten nach der Dicyclohexylcarbodiimid-Methode. Die niedermolekularen Überschüsse wurden durch Ultrafiltration abgetrennt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419741018
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  • 80
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    Asymmetrische Induktionen, VI1) Bestimmung der absoluten Konfiguration des (+)-4-Benzylidencyclohexancarbonsäure-äthylesters (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1684-1687 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Asymetric Inductions, VI. - Determination of the Absolute Configuration fo Ethyl (+)-4-BenzylidenencyclohexanecarboxylateThe reaction between (+)-(R)-benzylidene(methyl)phenyl(propyl)phosphorane (2) and ethyl4-oxocyclohexanecarboxylate gives carboxylate ][(+)-5]. The absolute configuration of (+)-5 could be determined by correlation with (+)-S)-4(4-methylcyclohexylidene)methylbenzene [(+)-9].
    Notes: Die Reaktionen von (+)-(R)-Benzyliden(methyl)phenyl(propyl)phorphoran (2) mit 4-Oxocyclohexancarbonsäure-äthylester führt zum (+)-4-Benzylidencyclohexancarbonsäure-äthylester [(+)-5]. Die Konfiguration von (+)-5 konnte durch Korrelieren mit (+)-(S)-(4-Methyl-cyclohexyliden)methylbenzol [(+)-9)] bestimmt werden.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419741020
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    Reaktionen mit Phosphinalkylenen, XXXI1) Synthese und Reaktionen von 1-Cyanalkylidentriphenylphosphoranen (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1688-1693 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reaction with Alkylidenetriphenylphosphoranes, XXXI1). - Synthesis and Reactions of 1-CyanoalkylidenetriphenylphosphoranesThe alkylidenetriphenylphosphoranes 1 react with 4-methylphenyl cyanate (2) to yield the 1-cyano ylids 3, which can be alkylated on the ylide C atom as well as on the N atom by alkylating reagents. Reaction of (cyanomethylene)triphenylphosphorane (3a) with ethyl bromoacetate leads to transylidation with formation of an ylide 14, which decomposes on thermolysis into methyl 3-cyanoacrylate (16) and triphenylphosphine. Compounds 3 undergo a Witttig reaction with aldehydes to form α-β-unsaturated nitriles.
    Notes: Die Alkylidentriphenylphosphorane 1 setzen sich mit 4-Methylphenylcyanat (2) zu den 1-Cyanyliden 3 um, die durch Alkylierungsreagentien sowohl am Ylid-C-Atom als auch am N-Atom alkyliert werden können. (Cyanmethylen)triphenylphosphoran (3a) reagiert mit Bromessigsäure-methylester unter Umylidierung zum Ylid 14, da bei der Thermolyse in 3-Cyanacrylsäure-methylester (16) und Triphenylphosphin zerfällt. Die Verbindungen 3 gehen mit Aldehyden Wittig-Reaktionen zu α-β-ungesättigten Nitrilen ein.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/jlac.197419741021
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  • 82
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    Reaktionen enolischer Zuckerderivate, X1) Allylaktivierung in 4- und 3-O-Tosylestern von Hex-5-enopyranosiden (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1675-1683 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Enolic Sugar Derivatives, X1). - Allylic Actiovation in 4- and 3-O-Tosylates of Hex-5-enopyranosidesMethyl-2,4-Di-O-acetyl-6-deoxy-3-O-tosyl-β-D-xylo- and α-L-arabino-hex-5-enopyranoside )2 and 5 as well as the corresponding 4-O-tosylates 8 and 11 were synthesized. The compounds react highly selectively under mild conditions. When treated with sodium methoxide, 2 yields the 3,4-anhydro compound 3 selectively via detosylation and deacetylation. Under the same conditions 5 and 8 yield the isomeric 3,4-anhydro compound 9 in analogous manner; 11 is converted into 3-hydroxy-6-methyl-4H-pyran-4-one (allomaltol, 12). In aqueous pyridine 8 is solvolyzed with inversion at C-4. On vinylogous substitution with sodium iodide, compounds 8 and 11 yield the methyl-2-3,-di-O-acetyl-4,6-dideoxy-6-iodo-α-L-threo-hex-4-enopyranoside (20).
    Notes: Methyl-2,4-di-O-acetyl-6-desoxy-3-O-tosyl-β-D-xylo-und α-L-arabino-hex-5-enopyranosid (2 bzw. 5) sowie die entsprechenden 4-O-Tosylverbindungen 8 und 11 wurden dargestellt. Die Verbindungen setzen sich unter milden Bedingungen mit hoher Selektivität um. Das Hex-5-enopyranosid 2 reagiert mit Natriummethylat unter Enttosylierung und Entacetylierung selektiv zu der 3,4-Anhydroverbindung 3 Aus 5 und 8 entsteht entsprechend die isomere 3,4-Anhydroverbindung 9, aus 11das 3-Hydroxy-6methyl-4-H-pyran-4-on (Allomaltol, 12). In wasserhaltigem Pyridin solvolysiert die Tosylgruppe von 8 glatt unter Inversion an C-4. Die 4-O-Tosylverbindungen 8 und 11 bilden durch vinyloge Substitution mit Natriumjodid Methyl-2,-3-di-O-acetyl-4-,6-didesoxy-6-jod-α-L-threo-hex-4-enopyranosid (20).
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/jlac.197419741019
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    Alkaloide aus Rhamnaceen, XVII1) Mauritin-C, -D, -E und -F; neue Peptidalkaloide aus Ziziphus mauritiana Lam.Herrn Prof. Dr. M. Viscontini, Zürich, herzlich zum 60. Geburtstag gewidmet. (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1694-1701 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Alkaloids from Rhamnaceae, XVII1). - Mauritine-C, -D, -E, and -F;New Peptide Alkaloids from Ziziphus mauritiana Lam.**In addition to mauritine-A and -B2), frangufoline3), and the previously known amphibines-B, -d, E4) an -F5), four new alkaloids, mauritine-c, -D, -E, and -F (3-6) were isolated from the mixture of bases from Ziziphus mauritiana Lam. and their structures elucidated. Alle these alkaloids belong to the same structural type with a 14-membered ring system containing trans-3-hydroxyproline, p-hydroxystyrylamine, and α-amino acid.
    Notes: Aus dem Rohbasengemisch von Ziziphus mauritiana Lam. wurden neben Mauritin-A und -B2), Franguforlin3) und den bereits bekannten Amphibinen-B, -D, -E4) und -F5) vier weitere Cyclopeptidalkaloide, die Mauritine-C, -D, -E (3-6) isoliert und deren Struktur aufgeklärt. Alle Alkaloide zählen zum gleichen Strukturtyp mit 14 gliedrigen Ringsystem aus trans-3-Hydrooxyprolin, p-Hydroxystryrylamin und einer α-Aminosäure.
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    URL: http://dx.doi.org/10.1002/jlac.197419741022
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    Berichtigung (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1726-1726 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419741026
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    Methylendihydrazin (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1851-1855 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: MethylenedihydrazineMethylenedihydrazine (3) was synthesized by reaction of hydrazine with tris(chloromethyl)-amine (1) or with the boron trifluoride adduct 4 · 3 BF3 of 1,3,5-trimethylhexahydro-s-triazine (4) and spectroscopically characterized. Reaction between methylhydrazine and tris(chloromethyl)amine (1) yields 1,4-dimethylhexahydro-s-tetrazine (5).
    Notes: Methylendihydrazin (3) wurde durch Umsetzung von Hydrazin mit Tris(chlormethyl)amin (1) oder mit dem Bortrifluoridaddukt 4 · 3 BF3 von 1,3,5-Trimethylhexahydro-s-triazin (4) dargestellt und spektroskopisch charakterisiert. Die Reaktion zwischen Methylhydrazin und Tris(chlormethyl)amin (1) liefert 1,4-Dimethylhexahydro-s-tetrazin (5)
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419741115
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    Photolyse von Benzoinalkyläthern in sauerstofffreien Lösungen (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1831-1842 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photolysis of Benzoin Alkyl Ethers in Oxygen-Free SolutionsThe quantum yields for the photodissociation of benzoin alkyl ethers on n-π*-excitation with 366 nm light have been measured as a function of the α-substituent, ether group, solvent and temperature. The primary step in the photoreaction is dissociation into a benzoyl radical 1 and an α-alkoxybenzyl radical 2, both of which have been detected by ESR spectroscopy at room temperature during the photolysis. Final products of the photolytically induced α-cleavage of benzoin methyl ether in oxygen-free benzene are the dimerization products of the primary radicals, benzil and 1,2-dimethoxy-1,2-diphenylethane, each in 40% yield. In oxygen-free alcohols the benzoyl radical reacts partially with the solvent as well as with the starting material to give benzoates and benzaldehyde, respectively. Product analysis after the photolysis of several specifically deuterated benzoin alkyl ethers permits elucidation of the reaction path of the primary radicals.
    Notes: Die Quantenausbeuten der Photolyse von Benzoinalkyläthern bei n-π*-Anregung mit der Wellenlänge 366 nm wurden in Abhängigkeit von den α-Substituenten, von der Äthergruppe, vom Lösungsmittel und von der Temperatur gemessen. Der Primärschritt der Photoreaktion ist die Dissoziation in ein Benzoylradikal 1 und ein α-Alkoxybenzylradikal 2, die durch direkten ESR-spektroskopischen Nachweis während der Belichtung nachgewiesen wurden. Endprodukte der photolytischen α-Spaltung von Benzoinmethyläther in sauerstofffreiem Benzol sind unter anderem zu je 40% die Dimerisierungsprodukte der beiden Primärradikale, Benzil und 1,2-Dimethoxy-1,2-diphenyläthan. Neben der Dimerisierung reagiert das Benzoylradikal in sauerstofffreien Alkoholen zum Teil mit dem Lösungsmittel unter Bildung von Benzoesäureester, zum Teil mit der Ausgangssubstanz unter Wasserstoffabstraktion zu Benzaldehyd. Durch Produktanalyse der bei der Photolyse spezifisch deuterierter Benzoinäther gebildeten deuterierten Endprodukte wurde der Reaktionsweg der Primärradikale gesichert.
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    URL: http://dx.doi.org/10.1002/jlac.197419741113
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    Riburonsäurederivate zur gezielten Veränderung der Ribose (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1856-1863 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Riburonic Acid Derivatives for Modification of the Ribose MoietyPermanganate oxidation of methyl-2,3-O-isopropylidene-β-D-ribofuranoside(2), which is readily available from D-ribose, provides a convenient method for the synthesis of methyl-2,3-O-isopropylidene-β-D-ribofuranosiduronic acid (5a), the methyl ester 5b of which is a key intermediate for directed chemical modification of the C-atoms 3, 4, and 5 of D-ribose. This is demonstrated by examples. The structures and conformations of the synthesized compounds are discussed.
    Notes: Die Permanganatoxidation von Methyl-2,3-O-isopropyliden-β-D-ribofuranosid (2), aus D-Ribose leicht zugänglich, stellt ein bequemes Verfahren zur Herstellung von Methyl-2,3-O-isopropyliden-β-D-ribofuranosiduronsäure (5a) dar. Ihr Methylester 5b ist eine Schlüsselsubstanz zur gezielten chemischen Veränderung der C-Atome 3, 4 und 5 der D-Ribose. Dies wird an einigen Beispielen gezeigt. Die Struktur und Konformation der hergestellten Verbindungen wird diskutiert.
    Additional Material: 1 Tab.
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    Formylierung von Benzylphosphonsäure-diäthylester und (Arylmethyl)phosphoniumsalzen (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1872-1875 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Formylation of Diethyl Benzylphosphonate and (Arylmethyl)phosphonium SaltsDiethyl benzylphosphonate (1) and (arylmethyl)triphenylphosphonium chlorides 5a-c (aryl = phenyl, 2-furyl, 2-thienyl) react with tert-butyloxy-N,N,N′,N′-tetramethylmethylene-diamine and with N,N-dimethylformamide diethyl acetal, respectively, to give the dimethylaminomethylene derivatives 2 and 6a - c. Diethyl α-(cyclohexylaminomethylene)benzylphosphonate (4) is formed from 2 and cyclohexylamine. Hydrolysis of 2 and 6a yields the benzyl compounds formylated at the α-position.
    Notes: Benzylphosphonsäure-diaäthylester (1) und (Arylmethyl)triphenylphosphoniumchloride 5a-c (Aryl = Phenyl, 2-Furyl, 2-Thienyl) reagieren mit tert.-Butoxy-N,N,N′,N′-tetramethylmethylendiamin bzw. N,N-Dimethylformamid-diäthylacetal zu den Dimethylaminomethylen-Derivaten 2 und 6a-c. Aus 2 entsteht mit Cyclohexylamin der α-(Cyclohexylaminomethylen)-benzylphosphonsäure-diäthylester (4). Die Hydrolyse von 2 und 6a liefert die an der α-Stellung formylierten Benzylverbindungen 3 und 7a.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419741118
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  • 89
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    13C-NMR-spektroskopische und stereochemische Untersuchungen, VII1) 13C-NMR-Verschiebungen und Bildungsgeschwindigkeiten von Trimethylsilyläthern (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1864-1871 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 13C-NMR Spectroscopic and Stereochemical Investigations, VII1.) - 13C-NMR Shifts and Formation Rates of Trimethylsilyl EthersThe trimethylsilylation rates of alcohols depend strongly on the steric environment of the OH group, as shown by a kinetic study with several cyclohexanols and bicyclo[2.2.1]heptanols. In the ethers there is no significant steric interaction between the bulky trimethylsilyl group and the rest of the molecule; this effect of the oxygen bridge can be seen in the invariable 13C-NMR shift of the trimethylsilyloxy groups and in the equilibrium between equatorial and axial cyclohexyl trimethyl ether, as determined by low temperature 13C-NMR signal integration. The 13C-NMR shift effects caused by introduction of the trimethylsilyl group can be used for signal assignments; the effects are compared with concentration dependent shifts of alcohols.
    Notes: Die Geschwindigkeit der Trimethylsilylierung von Alkoholen hängt stark von der sterischen Umgebung der OH-Gruppe ab, wie sich aus kinetischen Messungen mit Cyclohexanolen und Bicyclo[2.2.1]heptanolen ergibt. Wegen der Sauerstoffbrücke kommt es in den Äthern zu keiner sterischen Wechselwirkung der sperrigen Trimethylsilylgruppe mit dem übrigen Molekülrest; dies zeigt sich sowohl in der gleichbleibenden 13C-NMR-Verschiebung der Trimethylsilyloxygruppen wie in der tieftemperaturspektroskopisch ermittelten Gleichgewichtslage zwischen äquatorialem und axialem Cyclohexyl(trimethylsilyl)äther. Die durch die Einführung der Trimethylsilylgruppe hervorgerufenen 13C-NMR-Verschiebungseffekte können zur Signalzuordnung herangezogen werden und werden mit Konzentrationsabhängigkeiten der 13C-NMR-Verschiebungen von Alkoholen verglichen.
    Additional Material: 3 Tab.
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    URL: http://dx.doi.org/10.1002/jlac.197419741117
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  • 90
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    Darstellung von Zuckerestern über N-Acylimidazole1) (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 1-3 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation of Sugar Esters Via N-Acylimidazoles1)Reaction of the N-(tri-O-methylgalloyl)- and N-(tri-O-benzylgalloyl)imidazoles 1 and 2 with α-methyl-D-glucopyranoside furnished the corresponding 2,3,4,6-tetraacyl-derivatives 3 and 4 in short reaction times and good yields.
    Notes: Durch Umsetzung der N-(Tri-O-methylgalloyl)- und N-(Tri-O-benzylgalloyl)imidazole 1 und 2 mit α-Methyl-D-glucopyranosid wurden die entsprechenden 2,3,4,6-Tetraacyl-Derivate 3 und 4 in kurzen Reaktionszeiten und guten Ausbeuten erhalten.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419740102
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  • 91
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    Synthese und Reaktionen eines Pyrazolylmethylen-1,3-oxazolin-5-ons (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 37-43 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Reactions of a Pyrazolylmethylene-1, 3-oxazolin-one4-(1,3-Diphenyl-4-pyrazolylmethylene)-2-phenyl-1,3-oxazolin-5-one (2) has been synthesized from 1,3-diphenylpyrazol-4-carbaldehyde (1) and hippuric acid. The oxazoline ring of 2 is opened by amines forming the amides 3. Hydrolysis of 2 by acid or alkali as well as alkaline hydrolysis of the amides 3a, e afford the corresponding acid 4a. Reaction of 3 with hydroxyl-amine or of the amide 3a with sodium ethoxide leads to the imidazolinone derivatives 5 through substitution of the hetero oxygen by nitrogen. With hydrazine, 2 as well as 3f are converted into the pyrazolidinone derivative 6, while the amides 3a, e and the carboxylic acid 4a give the corresponding amidrazones 7. In boiling alkali the amide 3f yields the triazine derivative 8 by ring enlargement. Clemmensen reduction of2 affords 3-(1,3-di-phenyl-4-pyrazolyl)lactic acid (9).
    Notes: 4-(1,3-Diphenyl-4-pyrazolylmethylen)-2-phenyl-1,3-oxazolin-5-on (2) wird aus 1,3-Diphenyl-pyrazol-4-carbaldehyd (1) und Hippursäure synthetisiert. Mit Aminen findet Öffnung des Oxazolinrings unter Bildung der Amide 3 statt. Hydrolyse von 2 mit Säuren oder Alkalien sowie alkalische Hydrolyse der Amide 3a, e führen zur entsprechenden Säure 4a. Umsetzung von 2 mit Hydroxylamin oder des Amids 3a mit Natriumäthanolat ergibt unter Ersatz des Heterosauerstoffs durch Stickstoff die Imidazolinonderivate 5. Mit Hydrazin gehen 2 sowie 3f in das Pyrazolidinonderivat 6 über, während die Amide 3a und 3e sowie die Carbonsäure 4a die entsprechenden Amidrazone 7 liefern. Aus dem Amid 3f entsteht in siedenden Alkalien unter Ringerweiterung das Triazinderivat 8. Clemmensen-Reduktion von 2 führt zur 3-(1,3-Diphenyl-4-pyrazolyl)milchsäure (9).
    Additional Material: 2 Tab.
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    URL: http://dx.doi.org/10.1002/jlac.197419740106
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  • 92
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    Synthesen mit α-metallierten Isocyaniden, XXVII1) Umsetzungen von α-metalliertem Isocyanmethyl- und α-Isocyanbenzylphosphonsäure-diäthylester mit Carbonylverbindungen (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 44-53 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses with α-Metalated Isocyanides, XXVII1). - Reactions of α-Metalated Diethyl Isocyanomethyl- and α-Isocyanobenzylphosphonates with Carbonyl CompoundsDiethyl α-lithium-isocyanomethyl- and α-lithium-α-isocyanobenzylphosphonates (10 and 11) were reacted with the carbonyl compounds 12 and glyoxal to give respectively the vinyl iso-cyanides 16 and 1,4-diphenyl-l,3-butadienylene diisocyanide (17). - Diethyl isocyano-methylphosphonate (5) gives the diethyl2-oxazolin-4-ylphosphonates 18 on reaction with aldehydes (but not ketones) in ethanol in the presence of catalytic amounts of sodium cyanide. The oxazolines 18 give the N-(1-diethoxyphosphorylvinyl)formamides 13 on treatment with potassium tert.-butoxide in tetrahydrofuran.
    Notes: α-Lithium-isocyanmethyl- und α-Lithium-α-isocyanbenzylphosphonsäurediäthylester (10 bzw. 11) wurden mit dep Carbonylverbindungen 12 zu den Vinylisocyaniden 16 sowie mit Glyoxal zu 1,4-Diphenyl-l,3-butadienylendiisocyanid (17) umgesetzt. - Isocyanmethyl-phosphonsäure-diäthylester (5) reagiert in Äthanol in Gegenwart von Natriumcyanid als Katalysator mit Aldehyden (aber nicht mit Ketonen) zu den: 2-Oxazolin-4-ylphosphonsäure-diäthylestern 18. Diese sind mit Kalium-tert.-butanolat in Tetrahydrofuran in die N-(1-Diäthoxyphosphorylvinyl)formamide 13 umzuwandeln.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/jlac.197419740107
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  • 93
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    Borverbindungen, XXVI1) Wirkungsweise des Diäthylboryl-pivalats bei der N-Diäthyl-borylierung von Alkylaminen und von Ammoniak (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 101-111 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Boron Compounds, XXVI1). - Effect of Diethylboryl Pivalate on the N-Diethylborylation of Alkylamines and of AmmoniaThe effect of diethylboryl pivalate (1) on the catalytic diethylborylation of the primary amines 2 with triethylborane has been investigated. The 1 : 1 adducts 3, formed on the addition of amines [tert-butylamine (2a) and cyclohexylamine (2b)] to 1 react further in a two-step cycle with the additional amine 2. This reaction forms 1 mol each of alkylammonium pivalate 4 and alkylaminodiethylborane 5. The salts 4 and triethylborane react to regenerate 3 with the evolution of ethane. The separate steps of the catalytic cycle have been verified by various reactions on a preparative scale. - Reaction of ammonium pivalate with 2 mol of triethyl-borane affords the thermally stable 1 : 1 addition compound 6 of aminodiethylborane and 1. Under the catalytic conditions only one NH bond of ammonia reacts with triethylborane to give aminodiethylborane in high yield.
    Notes: Die Wirkungsweise des Diäthylboryl-pivalats (1) bei der katalysierten Diäthylborylierung der primaren Alkylamine 2 mit Triäthylboran wird untersucht. In einem Zweistufenzyklus reagieren die aus 1 und [z. B. tert.-Butylamin (2a), Cyclohexylamin (2b)] entstehenden 1 : 1-Additionsverbindungen 3 zunächst mit einem zweiten Molekül 2. Dabei bilden sich je 1 mol Alkylammonium-pivalat 4 und Alkylaminodiathylboran 5. Die Salze 4 liefern mit Triäthylboran unter Abspaltung von Äthan 3 zurück. Die einzelnen Reaktionsstufen des Katalysezyklus werden mit präparativen Beispielen belegt. - Aus Ammoniumpivalat gewinnt man mit 2 mol Triathylboran die thermisch stabile 1 : 1-Additionsverbindung 6 von Aminodiäthylboran und 1. Beim Ammoniak reagiert nur eine NH-Bindung unter den Katalysebedingungen mit Triäthylboran; in hoher Ausbeute entsteht Aminodiäthylboran.
    Additional Material: 4 Tab.
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    URL: http://dx.doi.org/10.1002/jlac.197419740110
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    Ramanspektroskopie und Molekülstruktur, VII1) Infrarot-, Raman- und Photoelektronenspektrum des Hexamethyl-Dewarbenzols; Normalkoordinatenberechnung und Untersuchung der π-Elektronen-Wechselwirkunga) (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 137-156 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Raman Spectroscopy and Molecular Structure, VII1). - Infrared, Raman and Photoelectron Spectrum of Hexamethylcommat( Dewar Benzene) Normal Coordinate Calculations and Investigation of π-Electron Interaction α′The frequencies and modes of all vibrations of hexamethyl(Dewar benzene) have been calculated. The frequencies thus obtained agree within a mean deviation of 1.3 % with the values observed in the infrared and Raman spectra. The calculated force constants give no indication of ring-strain effects. However, some of the calculated force constants deviate from the expected values. The bond orders derived from force constants according to Siebert) are 0.87 for the central Cl—C4-bond and 1.64 for the C=C-bonds. Surprisingly. The bond orders of the neighbouring single bonds hardly deviate from unity. - The photoelectron spectrum shows a π-electron ionisation potential splitting of 0.41 eV; this is attributed to the competing direct through-space interaction of the π-orbitals as well as to coupling with the central 1,4-σ-orbital. The latter mechanism predominates, and leads to an “inverted” order of the π-orbital energies.
    Notes: Die Frequenzen und Formen sämtlicher Schwingungen des Hexamethyl-Dewarbenzols wurden berechnet. Diese Frequenzen stimmen, bei einer mittleren Abweichung von 1.3 %, mit den im Infrarot- und Ramanspektrum gemessenen überein. Die bei der Berechnung ermittelten Kraftkonstanten zeigen keine Auswirkung der “Ringspannung” des Moleküls. Einige Kraftkonstanten weichen jedoch von den erwarteten Werten ab. Die aus den Kraftkonstanten nach Siebert9) ermittelte Bindungsordnung der zentralen C1 —C4-Bindung beträgt 0.87 und die der C=C-Bindungen 1.64, ohne daß die Bindungsordnung der benachbarten Einfachbindungen wesentlich von 1 abweicht. - Das Photoelektronenspektrum des Hexamethyl-Dewarbenzols zeigt eine Aufspaltung der Ionisationspotentiale der π-Elektronen um 0.41 eV, diese ist auf die gleichzeitige direkte Wechselwirkung der n-Orbitale durch den Raum und durch Kopplung mit dem zentralen (C1 —C4)-σ-Orbital zurückzuführen. Wir sind der Meinung, daß der zuletzt genannte Mechanismus überwiegt und zu einer “invertierten” Ordnung der Energie der π-Orbitale führt.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419740114
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    Isolierung und Struktur von Larreagenin A (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 169-175 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Isolation and Structure of Larreagenin AFour glycosides have been isolated from leaves of the central american plant Larreu divaricata Cav.; the structure of one of the aglycons, larreagenin A, has been elucidated by means of 1H-NMR- and 13C-NMR-investigation together with other spectroscopic data as 3β-hydro-xy-29-nor-urs-13(18)-en-20β,28β-olide (4). Larreic acid, isolated from the same plant as glycoside, can be isomerized to larreagenin A.
    Notes: Aus Blättern der mittelamerikanischen Pflanze Lurrea divaricata Cav. wurden 4 Glykoside isoliert; die Struktur eines der Aglyka, das Larreagenin A wurde mit Hilfe von 1H-NMR- und 13C-NMR-Untersuchungen sowie anderer spektroskopischer Daten als 3β-Hydroxy-29-nor-urs-l3(18)-en-20β,28β-olid (4) aufgeklärt. Die aus der gleichen Pflanze als Glykosid isolierte Larreasäure läßt sich zu Larreagenin A isomerisieren.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/jlac.197419740202
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    Synthese von Indian-Derivaten aus trans-1,4,9-DecatrienVortrag anläßlich der GDCh-Tagung an der Techn. Universität Karlsruhe am 17.Sept. 1971. (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 176-182 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of Indan Derivatives from trans-1,4,9-Decatriene*Trienoic hydrocarbons with isolated double bonds or with two conjugated double bonds separated from the third one by at least two methylene groups lead inter alia to 3a,4,5,7a-tetrahydroindan derivatives in the presence of alkali. Thus in the reaction of trans-1,4,9-decatriene (1) with alcoholic NaOH, 5-methyl-3a,4,5,7a-tetrahydroindane (3) is formed besides 5,6-dialkyl-1,3-cyclohexadienes 6. The reactions of 1 with aqueous NaOH on the other hand yields the tetrahydroindan 3 as the only cyclization product. - 5-Methyl-3a,4,5,7a-tetrahydroindan (3) is also formed on heating 1,6,8-decatriene (2a). Substance 2a is prepared from 1 by isomerization with potassium tert.-butoxide. - The mechanism of the cyclization of 1 in alkaline media is discussed.
    Notes: Trienkohlenwasserstoffe mit isolierten Doppelbindungen oder mit zwei konjugierten Doppelbindungen, die von der dritten durch mindestens zwei Methylengruppen getrennt sind, führen in Gegenwart von Alkali unter anderem zu 3a,4,5,7a-Tetrahydroindan-Derivaten. So entsteht bei der Umsetzung von trans-1,4,9-Decatrien (1) mit alkoholischer NaOH neben 5,6-Dialkyl-1,3-cyclohexadienen 6 das 5-Methyl-3a,4,5,7a-tetrahydroindan (3). Die Umsetzung von 1 mit wäßriger NaOH liefert dagegen als einziges Cyclisierungsprodukt das Tetrahydroindan 3. - 5-Methyl-3a,4,5,7a-tetrahydroindan (3) entsteht auch durch Erhitzen von 1,6,8-Decatrien (2a). Dazu wird 2a aus 1 durch Isomerisierung mit Kalium-tert.-Butylat hergestellt. - Der Mechanismus der Cyclisierung von 1 in alkalischen Medien wird diskutiert.
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    URL: http://dx.doi.org/10.1002/jlac.197419740203
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    Synthesen von Heterocyclen, 1781) Synthesen von Chromanonen und Chromonen (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 195-200 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses of Heterocycles, 1781). - Syntheses of Chromanones and ChromonesThe Fries rearrangement of diphenyl fumarates 1a-c and diphenyl chlorofumarates 6a-b yields derivatives (2a-c and 7a-b) of 2-butene-1,4-dione. These compounds can be cyclized to chromanones 3a-c and chromones 8a-b.
    Notes: Aus den Fumarsäurediphenylestern 1a-c und Chlorfumarsäure-diphenylestern 6a-b erhält man durch doppelte Friessche Verschiebung Derivate (2a-c und 7a- b) des 2-Buten-1,4-dions, welche sich anschließend zu Chromanonen 3a-c und Chromonen 8a-b cyclisieren lassen.
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    URL: http://dx.doi.org/10.1002/jlac.197419740206
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    Modellversuche zur Synthese von Anhydrogliotoxin-Analoga: Eine bequeme Synthese von Thiazoloindolon-Derivaten (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 206-212 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Model Experiments for the Synthesis of Anhydrogliotoxin Analogs: A Convenient Synthesis of Thiazoloindolone DerivativesThe addition of thioglycolic acid (11, R=H) or 2-mercaptopropionic acid (12, R=H) to ethyl 2-ethoxycarbonyl-3,3-dimethylindolenine (5) yields the hexahydrothiazolo[3,2-a]-indolones 6 and 14, respectively. When the ethyl ester 11 (R=C2H5) is used instead of the acid 11 (R = H), this reaction proceeds only in the presence of a trace of acid. - Compound 6 can be converted into the a,cw-dichlorosulfenyl chloride 18, which reacts quantitatively with ethanethiol to yield19. 3-Mercaptopropionic acid (21) reacts with 5 to yield 22. The conversions of 6 → 19 and 5 → 22 are model reactions for the synthesis of the seco-anhydrogliotoxin analog 20 and the dethiornethyleneanhydrogliotoxin analog 24, respectively. First attempts in this direction are discussed.
    Notes: Die Addition von Thioglykolsäure (11, R = H) oder 2-Mercaptopropionsäure (12, R = H) am 2-Äthoxycarbonyl-3,3-dirnethylindolenin (5) führt zu den Hexahydrothiazolo[3,2-a]- indolonen 6 bzw. 14. Verwendet man statt der Säure 11 (R = H) deren Äthylester 11,/ (R=C2H5), so verläuft die Reaktion nur in Anwesenheit von Spuren einer Säure. - Die Verbindung 6 wird zum α,α-Dichlorsulfenylchlorid 18 umgesetzt, das mit Äthanthiol quantitativ unter Bildung von 19 reagiert. 3-Mercaptopropionsaure (21) reagiert mit 5 unter Bildung von 22. Die Umwandlungen von 6 in 19 und von 5 in 22 sind Modellreaktionen für die Synthese des seco-Anhydrogliotoxin-Analogons 20 bzw. des Desthiornethylenanhydrogliotoxin-Analogons 24. Erste Versuche dazu werden diskutiert.
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    URL: http://dx.doi.org/10.1002/jlac.197419740208
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    Über die Oxidationsprodukte von Thiocarbonsäureamiden, XXIX1) Konfiguration alkyl- und aryl-substituierter Thioharnstoff-S-trioxide (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 243-252 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Oxidation Products of Carbothioamides, XXIX1). - Configuration of Alkyl- and Aryl-Substituted Thiourea S-TrioxidesMonoalkyl-, monoaryl-, and dialkyl-substituted thioureas are easily oxidized to thiourea S-trioxides. Like 1,3-di-tert.-butylthiourea, tribenzylthiourea gives formamidinium alkyl-sulfates on oxidation in different solvents, the nature of the alkyl group being determined by the solvent used. - The 1H-NMR parameters of the thiourea S-trioxides are recorded as functions of the substituents, and proton exchange, hindered internal rotation about the C2-N-bonds, and the configuration are discussed and compared with those in thioureas.
    Notes: Monoalkyl-, monoaryl- und dialkyl-substituierte Thioharnstoffe lassen sich glatt zu den Thioharnstoff-S-trioxiden oxidieren. Tribenzylthioharnstoff liefert bei der Oxidation in verschiedenen Lösungsmitteln ebenso wie 1,3-Di-tert.-butylthioharnstoff Formamidinium-alkyl-sulfate, wobei die Art des Alkylrestes durch das Lösungsmittel bestimmt wird. - 1H-NMR-spektroskopisch werden bei den Thioharnstoff-S-trioxiden Protonenaustauscheffekte, behinderte Rotation um die C2-N-Bindungen und die Konfiguration in Abhängigkeit von den Substituenten untersucht und mit den Verhältnissen bei Thioharnstoffen verglichen.
    Additional Material: 6 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419740211
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    Über die Struktur der Thioamide und ihrer Derivate, XXVIII1) Über intramolekulare Wechselwirkungen in N,N′-Diacylbenzimidazolinen (1974)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1974 (1974), S. 274-282 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Structure of Thioamides and Their Derivatives, XXVIII1). - Intramolecular Interactions in N,N′-DiacylbenzimidazolinesN,N′-Diacylbenzimidazolines 5 exhibit hindered rotation around the partial C···N double bond. The coplanar arrangement of the amide groups and the benzene ring leads to steric interactions between the acyl groups and the ortho-protons of the aromatic ring. The preference of the E1, Z3 and Z1, E3 structures shows that there is an additional mutual influence between the acyl groups. The dipoles of the C=O or C=S bonds compensate each other in the E,Z structure so that it is favoured over the E,E and Z,Z isomers for electrostatic reasons.
    Notes: N,N′-Diacylbenzimidazoline 5 zeigen eine behinderte Rotation urn die partielle C···N-Doppelbindung. Die koplanare Anordnung der Acylgruppen und des Benzolkernes führt zu sterischen Wechselwirkungen zwischen den Säureresten und den ortho-Protonen des aromatischen Ringes. Eine zusätzliche gegenseitige Beeinflussung der Acylgruppen zeigt sich in der Bevorzugung der isomeren Formen E1, Z3 und Z1, E3, wenn dem keine sterischen Gründe entgegenstehen. In diesen Strukturen kompensieren sich die Bindungsmomente der C=O- oder der C=S-Bindungen, so daß sie gegenüber den E,E- und Z,Z-Isomeren aus elektrostatischen Gründen begünstigt sind.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197419740213
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