Sythese von α und β-Sinensal

β-Sinensal (2,6-dimethyl-10-methylene-dodeca-2,6,11-trienal) was synthesized from the diene-aldehyde 5 . This was converted into the trans- and cis-triene-aldehydes 16 and 17 , which were condensed with the phosphorane 18 to give the corresponding two geometrical isomers ( 3 and 19 ) of β-sinensal.     

Synthese von diastereo- und enantio-selektiv deuterierten β,ε-, β,β-, β,γ- und γ,γ-Carotinen

Synthesis of Diastereo- and Enantioselectively Deuterated β,ε-, β,β-, β,γ- and γ,γ-Carotenes We describe the synthesis of (1′R, 6′S)-[16′, 16′, 16′-²H₃]-β, εcarotene, (1R, 1′R)-[16, 16, 16, 16′, 16′, 16′-²H₆]-β, β-carotene, (1′R, 6′S)-[16′, 16′, 16′-²H₃]-γ, γ-carotene and (1R, 1′R, 6S, 6′S)-[16, 16, 16, 16′, 16′, 16′-²H₆]-γ, γ-carotene by a multistep degradation of (4R, 5S, 10S)-[18, 18, 18-²H₃]-didehydroabietane to optically active deuterated β-, ε- and γ-C₁₁-endgroups and subsequent building up according to schemes \documentclass{article}\pagestyle{empty}\begin{document}${\rm C}_{11} \to {\rm C}_{14}^{C_{\mathop {26}\limits_ \to }} \to {\rm C}_{40} $\end{document} and C₁₁ → C₁₄; C₁₄+C₁₂+C₁₄→C₄₀. NMR.- and chiroptical data allow the identification of the geminal methyl groups in all these compounds. The optical activity of all-(E)-[²H₆]-β,β-carotene, which is solely due to the isotopically different substituent not directly attached to the chiral centres, is demonstrated by a significant CD.-effect at low temperature. Therefore, if an enzymatic cyclization of [17, 17, 17, 17′, 17′, 17′-²H₆]lycopine can be achieved, the steric course of the cyclization step would be derivable from NMR.- and CD.-spectra with very small samples of the isolated cyclic carotenes. A general scheme for the possible course of the cyclization steps is presented.     

Die Kristallstruktur von β-RbScO2

The Crystal Structure of β-RbScO₂ Single crystals of β-RbScO₂ have been prepared. β-RbScO₂ crystallizes hexagonal, a = 3.25₁, c = 12.78₆ Å. The structure has been refined by 4-cyclediffractometer data.     

Die Kristallstrukturen von α- und β-K3OCl

The Crystal Structures of α- and β-K₃OCl The orange coloured compound K₃OCl has been prepared. It exists in a low temperature modification (α-K₃OCl) and a high temperature modification (β-K₃OCl). The transition temperature is 364 ± 5 K. The crystal structures were determined by x-ray diffraction. α-K₃OCl crystallizes at room temperature in the orthorhombic space group Pbnm (Z = 4) with the cell parameters a = b = 723.9(2) pm and c = 1 027.7(2) pm in the anti-GdFeO₃-structure type. The high temperature modification β-K₃OCl crystallizes (Z = 1) in the cubic space group Pm3m in the β-Ag₃SI-structure type with a = 516.2(2) pm (T = 393 K).