Crystal and molecular structures of two unsaturated monosaccharides: methyl 6-(N-benzenesulfonylamino)-N,O-isopropylidene-2,3,6,8-tetradeoxy-α-D-erythrooct-2-enopyranos-4-uloside,and 1,1-O,O-ethylidene-3,4-dideoxy-D,L-hex-3-enoz-2-ulopyranos-5-ulose

Methyl 6-(N-benzenesulfonylamino)-N,O-isopropylidene-2,3,6,8-tetradeoxy--d-erythrooct-2-enopyranos-4-uloside, C₁₈H₂₃N₁O₆S₁, (3) crystallizes in the orthorhombic space groupP2₁2₁2₁. The unit cell parameters are:a=7.839(2),b=10.111(2),c=24.217(5) Å. The dihydropyranone ring adopts a deformed sofa conformation with the O5 atom deviating 0.586(2) Å from the least-squares plane and the -face of the carbonyl group shielded by the terminal (C8) methyl group. 1,1-O,O-Ethylidene-3,4-dideoxy-d,l-hex-3-enoz-2-ulopyranos-5-ulose, C₈H₁₀O₅, (6) crystallizes in the monoclinic space groupP2₁/n. The unit cell parameters are:a=6.310(1),b=18.656(3),c=7.604(1) Å, =106.01(1)°. The dihydropyranone ring adopts a deformed sofa conformation with O6 atom deviating 0.482(1) Å from the leastsquares plane and the hydroxy and dioxolanyl substituents are in pseudoaxial and pseudoequatorial positions, respectively. The average planes of six-membered and five-membered rings are approximately coplanar.     

Structure of 4-thioethyl-4-cholesten-3-one,C29H48OS

The crystal structure of 4-thioethyl-4-cholesten-3-one, C₂₉H₄₈OS, has been determined by X-ray methods. The compound is orthorhombic:P2₁2₁2₁,a=7.787(2),b=12.586(4),c=27.960(6) Å,V=2740(3) ų,M _r =444.8,Z=4,D _x =1.08 Mg m^–3, CuK radiation (=1.5418 Å),=11.2 cm^–1,F(000)=984. FinalR=0.073 andR _w =0.057 for 1562 reflections. A comparison with other 4-substituted 4-en-3-ore steroids suggests that theA ring conformation and its relative orientation can be influenced by the thioethyl substituent. The C4 side chain is turned under the steroid skeleton. The cholesterol side chain is fully extended, with atrans, +gauche conformation of the terminal C26 and C27 methyl groups.     

Synthese,Kristallstruktur und Konformation von N2-Dibenzyl-N1-t-butoxycarbonylhydrazin

Summary The synthesis and the crystal structure of N²-dibenzyl-N¹-butoxycarbonyl hydrazine are reported. The compound was prepared from commercially availablet-butyl carbazate. It crystallizes in the triclinic space group P 1 witha=5.479(1) Å,b=9.559(1) Å,c=9.748(1) Å,a=63.81(1)°, =87.52(1)°, =74.07(1) Å,Z=1,D=1.18 g/cm³. The structure was solved by direct methods and refined toR=0.0329.

     

The initiation properties of 2-cyano-2-propyl hydroperoxide in oxidation processes

The initiating ability of 2-cyano-2-propyl hydroperoxide in the oxidation reaction of cumene by molecular oxygen has been investigated and compared with the initiating ability of cumene hydroperoxide.

---

Die Initiierungseigenschaften von 2-Cyano-2-propyl-hydroperoxid bei Oxydations-prozessen

Zusammenfassung Es wurde die Initiierungsfähigkeit des 2-Cyan-2-hydroperoxypropans in der Oxidation von Cumol mit molekularem Sauerstoff untersucht und mit der Initiierungsfähigkeit des Cumolhydroperoxids verglichen.

     

Improvement of polarized double-zeta basis sets for molecular interactions. Complexes of NH3, OH2, and FH with H+ and Li+

Interaction energies of a proton and lithium cation with NH₃, OH₂, and HF axe computed at the SCF and Møller-Plesset levels. It is found that the basis set superposition errors at all levels with the 6-3 1G** basis set may be greatly reduced by including an additional diffuse sp shell on first-row atoms; the exponent of this shell has been optimized to 0.1.     

Synthesis and Alkaline Metal Ion Binding Ability of New Steroid Dimers Derived from Cholic and Lithocholic Acids

The synthesis and NMR spectra of steroid dimers being derivatives of cholic and lithocholic acid methyl esters, in which the steroid residues are linked by the terephthaloyl spacer, are described. The complexing ability of the dimers towards alkaline metal cations has been studied by the electrospray mass spectrometry. Cholic acid derivatives show affinity toward metal cations and anions. Binding of metal cations by methyl lithocholate dimer has not been detected.     

2-Thion-5-mercapto-1,3,4-thiadiazolidin als Reagens für die photometrische Bestimmung von Platin(IV), Palladium(II) und Osmium(VIII)

A method for the photometric determination of platinum(IV), palladium(II) and osmium(VIII) with 5-mercapto-thiadiazolidine-thione-2 is described. The effects of an excess of reagent, of time, pH and of diverse ions were studied. The optimum concentration range for the method is 10 to 100 Μg of Pt(IV), Pd(II) and Os(VIII).