Triphen­yl(prop-2-yn-1-yl)silane

In the title compound, C21H18Si, the coordination geometry around the Si atom is a slightly distorted tetra­hedron with C—Si—C angles in the range 106.05 (11) to 110.58 (10) ° and Si–C bond lengths in the range 1.855 (2) to 1.883 (3) Å. The alkyne C—C bond length is 1.167 (4) Å. The dihedral angles between the three phenyl rings are 63.89 (7), 86.38 (7) and 70.51 (8)°. In the crystal, mol­ecules inter­act only by van der Waals forces

(2SR,3SR)-Isopropyl 3-{[dimeth­yl(phenyl)­sil­yl]meth­yl}-2-hy­droxy-2-vinyl­pent-4-enoate

The relative configuration of the title compound, C19H28O3Si, which was synthesized using a dienolate-[2,3]-Wittig rearrangement, was corroborated by single-crystal X-ray diffraction analysis. The Si—C bond distances are in the range 1.858 (2)–1.880 (2) Å and an intra­molecular O—H⋯O hydrogen bond helps to stabilize the mol­ecular conformation

(3S,4S,5R)-4-Hydr­oxy-3-methyl-5-[(2S,3R)-3-methyl­pent-4-en-2-yl]-4,5-dihydro­furan-2(3H)-one

The relative configuration of the title compound, C11H18O3, was corroborated by single-crystal X-ray diffraction analysis. In the crystal, mol­ecules are linked via a O—H⋯O hydrogen bond and a chain of mol­ecules is formed along [010]

(3R,4R,5S)-4-Hydr­oxy-3-methyl-5-[(2S,3R)-3-methyl­pent-4-en-2-yl]-4,5-dihydro­furan-2(3H)-one

The relative configuration of the title compound, C11H18O3, which was synthesized using a catalytic asymmetric Gosteli–Claisen rearrangement, a diastereoselective reduction with K-Selectride and an Evans aldol addition, was corroborated by single-crystal X-ray diffraction analysis. The five-membered ring has an envelope conformation with a dihedral angle of 29.46 (16)° between the coplanar part and the flap (the hydr­oxy-bearing ring C atom). In the crystal, mol­ecules are connected via bifurcated O—H⋯(O,O) hydrogen bonds, generating [010] chains

Der Leipziger Gewerbeschullehrer August Föppl und die Theoretisierung der Technik

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Datengenerierung in Automationsgeräten, Datenintegration und Visualisierung in CPS-Leitständen

Der durchgängige Einsatz von ETHERNET-Technologien in der Industrie ermöglicht den Durchgriff auf Daten von der (Werks-)Leitebene bis in die Feldebene (Aktoren und Sensoren). Die Realisierung dieser Funktionen bedarf struktureller und funktioneller Festlegungen und Normative, an die Entwickler und Nutzer zu binden sind. Die konzipierten und umgesetzten Daten-Erfassungs-, -Übertragungs- und -Visualisierungskonzepte konnten in ihrer Funktionsfähigkeit demonstratorhaft nachgewiesen werden. Eine Anpassung auf weitere Technologien ist möglich und im Zuge der Weiterentwicklung in Richtung Vermarktbarkeit vorgesehen

(±)-syn-Isopropyl 4-(1,1,1,3,3,3-hexa­fluoro­propan-2-yl­oxy)-1-hydr­oxy-3-methyl-2-(prop-1-yn­yl)cyclo­pent-2-ene­carboxyl­ate

The title compound, C16H18F6O4, was obtained through an unprecedented one-pot reaction sequence involving a Gosteli–Claisen rearrangement and a cyclo­isomerization. The constitution and relative configuration were determined by single-crystal X-ray diffraction analysis. In the crystal, mol­ecules are connected via O—H ⋯ O hydrogen bonds

(4R)-4-Benzyl-3-{(4S)-4-chloro-4-[(S)-2,2-dimethyl-1,3-dioxolan-4-yl]butano­yl}-1,3-oxazolidin-2-one

The title compound, C19H24ClNO5, was synthesized and subsequently employed in an Evans alkyl­ation. The purpose was to prove the absolute configuration in the projected synthesis of the side chain of (–)-Lytophilippine A. The oxazolidinone and the isopropylidene acetal rings have twisted conformations. The oxazolidinone and side-chain carbonyl groups are orientated in an anti­periplanar arrangement to minimize van der Waals repulsions. Furthermore, the Cl atom and the acetonide-protected secondary alcohol are also in an anti­periplanar arrangement with a torsion angle of 173.64 (14)°. The absolute configuration was determined and agrees with the configuration of the used chiral auxiliary

(3R,4S,5S)-4-Hydr­oxy-3-methyl-5-[(2S,3R)-3-methyl­pent-4-en-2-yl]tetra­hydro­furan-2-one

The title compound, C11H18O3, was synthesized to prove the relative configuration of the corresponding acyclic C1—C8 stereopentade. It crystallizes with two mol­ecules in the asymmetric unit, which show only slight differences. The mol­ecules are linked via O—H⋯O hydrogen bonds, resulting in two crystallographically independent chains of mol­ecules propagating in the a-axis direction. The absolute configuration was known from the synthesis

{2,2-Bis[(4S)-4-tert-butyl-4,5-dihydro-1,3-oxazol-2-yl]propane}bis­(N,N-di­methyl­formamide)copper(II) bis­(hexa­fluoridoantimonate)

In the title compound, [Cu(C17H30N2O2)(C3H7NO)2][SbF6]2, which is a potential catalyst in the asymmetric Gosteli–Claisen rearrangement, the Cu atom adopts a distorted cis-CuN2O2 square-planar geometry arising from N,N′-bidentate coordin­ation by the chiral ligand and two O-bonded dimethyl­formamide mol­ecules. Two short C—H⋯O contacts occur within the ligand and two weak inter­molecular C—H⋯F bonds may help to establish the packing