Synthese von aromatischen Verbindungen mit einer prostaglandin-ähnlichen Struktur

Synthesis of Aromatic Compounds with a Prostaglandin-like Structure The syntheses of two prostaglandin-like molecules with aromatic nuclei instead of the usual 5membered ring are described.     

Über die Reaktion von Tellur mit Wolframhalogeniden: Synthese und Struktur von Te7WOCl5, einer Verbindung mit einem polymeren Tellur-Kation

On the Reaction of Tellurium with Tungsten Halides: Synthesis and Crystal Structure of Te₇WOCl₅, a Compound with a Polymer Tellurium Cation The reaction of tellurium with WOCl₄ in the presence of a large excess of WCl₆ in a sealed evacuated glass ampoule at 150°C yields beside the main product Te₈(WCl₆)₂ a small amount of Te₇WOCl₅. The crystal structure determination (orthorhombic space group Pcca, lattice parameters at 173 K: a = 2 596.5(9) pm, b = 810.0(3) pm, c = 775.7(2) pm) shows that Te₇WOCl₅ is built of one-dimensional band shaped polymeric tellurium cations, one-dimensional associated pyramidal WOCl₄^? anions and of isolated Cl^? anions. Te₇WOCl₅ can thus be formulated as [Te₇²⁺]_n [WOCl₄^?]_n (Cl^?). The structure is closely related but not isotypic to the bromine containing analogue Te₇WOBr₅. The difference between the two structures lies in different directions of the polar [WOX₄^?]_n chains (X = Cl, Br). The strongly elongated thermal ellipsoid of one tellurium atom is shown to be caused by thermal vibration by determing the crystal structure of Te₇WOCl₅ at three different temperatures (223, 173 and 123 K). All displacement parameters of all atoms can be extrapolated to zero for 0 K.     

Synthese und Chiralität von (5S, 6R)-5,6-Epoxy-5,6-dihydro-β,β-carotin und (5R, 6R)-5,6-Dihydro-β,β-carotin-5,6-diol,einem Carotinoid mit ungewöhnlichen Eigenschaften

Synthesis and Chirality of (5S,6R)-5,6-Epoxy-5,6-dihydro-β,β-carotene and (5R,6R)-5,6-Dihydro-β,β-carotene-5,6-diol, a Compound with Unexpected Solubility Characteristics Wittig-condensation of azafrinal ( 1e ) with the phosphorane derived from 7 leads to a (1:3)-mixture of (E)-9′- and (Z)-9′-β,β-carotene-diol 3 , from which pure and optically active 3 ((5R,6R)-5,6-dihydro-β,β-carotene-5,6-diol) has been isolated as bright violet leaflets, m.p. 168°. Due to the trans-configuration of the diol moiety and to severe steric hindrance, hydrogen bonding is reduced to such an extent, that 3 behaves much more as a hydrocarbon than as a diol. There is good evidence that the so-called ‘β-oxycarotin’ obtained by Kuhn & Brockmann [15] by chromic acid oxidation of β, β-carotene is the corresponding racemic cis-diol. 3 has been converted into (5S, 6R)-5,6-epoxy-5.6-dihydro-β,β-carotene ( 4 ), m.p. 156°. This transformation establishes for the first time the chirality of a caroteneepoxide (without other O-functions). Full spectral and chiroptical data including a complete assignement of ¹³C-chemical shifts for azafrin methyl ester and 3 are presented.     

Synthese und Struktur von Zr4ON3F5, einer Verbindung mit fluorit-verwandter Überstruktur vom Vernier-Typ

Synthesis and Structure of Zr₄ON₃F₅, a Compound with a Fluorite Related Superstructure of the Vernier Type Ammonolysis of β? ZrF₄ or ZrF₄ · NH₃ yields zirconium nitride fluoride ZrNF and zirconium oxide nitride fluoride Zr₄ON₃F₅. Electron diffraction and electron energy loss spectroscopy were used to distinguish these two ammonolysis products by structure and composition. ZrNF crystallizes isotypically to baddeleyite ZrO₂ in the space group P2₁/c with the lattice constants a = 522.7(3), b = 502.6(2), c = 519.1(3) pm, β = 98.98(7)°, Z = 4, while Zr₄ON₃F₅ forms an anion-excess fluorite-related structure of the vernier type. The structure of Zr₄ON₃F₅ was refined from neutron powder diffraction data. It crystallizes monoclinic in space group P112₁/b with lattice constants a = 512.17(3), b = 2 151.3(1), c = 536.69(3) pm, γ = 90.128(6)°, Z = 4. Within the homologous series M_nX_2n+1 of the vernier phases Zr₄ON₃F₅ is a member with n = 4.