Structural Studies of Crystalline Enamines

Authors

  • Kevin L. Brown,

    1. Organic Chemistry Laboratory, Swiss Federal Institute of Technology, ETH-Zentrum, CH-8092 Zürich
    Current affiliation:
    1. Chemistry Division, D. S. I. R., Petone, New Zealand
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  • Lorenz Damm,

    1. Organic Chemistry Laboratory, Swiss Federal Institute of Technology, ETH-Zentrum, CH-8092 Zürich
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  • Jack D. Dunitz,

    1. Organic Chemistry Laboratory, Swiss Federal Institute of Technology, ETH-Zentrum, CH-8092 Zürich
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  • Albert Eschenmoser,

    1. Organic Chemistry Laboratory, Swiss Federal Institute of Technology, ETH-Zentrum, CH-8092 Zürich
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  • Reinhard Hobi,

    1. Organic Chemistry Laboratory, Swiss Federal Institute of Technology, ETH-Zentrum, CH-8092 Zürich
    Current affiliation:
    1. Institut für Pharmakologie und Biochemie der Vet. Med. Fakultät der Universität Zürich
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  • Christoph Kratky

    1. Organic Chemistry Laboratory, Swiss Federal Institute of Technology, ETH-Zentrum, CH-8092 Zürich
    Current affiliation:
    1. Institut für Physikalische Chemie, Universität Graz, A-8010 Graz, Österreich
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Abstract

Crystal structure analyses of five crystalline enamines together with recently published structural data for two other enamines reveal varying degree of pyramidality at the enamine nitrogen atom. The pyramidality appears to be most pronounced in enamines from piperidine and morpholine, less so in enamines derived from prolinoid amines. A pyrolidine enamine obtained from a derivative of cyclohexane-1,4-dione seems to have a virtually planar enamine group. The implications of these findings for current stereochemical problems in enamine chemistry are discussed.

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