منابع مشابه
3β,12β,14α-Trihydroxypregnan-20-one
The title compound, C(21)H(34)O(4), is a steriod of the pregnane family prepared by the sequential oxidation and reduction of 3β,12β-diacet-oxy-20-ethyl-enedioxy-pregnan-14-ene. The con-formations of the six-membered rings are close to chair forms, while the five-membered ring adopts an envelope conformation. All the rings are trans-fused and an intra-molecular O-H⋯O hydrogen bond occurs. In th...
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In the title compound, C(23)H(34)O(4), the C/D and D/E rings are trans fused and the A/B ring possesses an anti fusion. The two cyclo-hexane rings adopt a chair conformation while the cyclo-hexene ring exhibits a half-chair conformation. The cyclo-pentane ring displays an envelope conformation with the C atom bearing the methyl group as the flap. In the crystal, the mol-ecules are linked by O-H...
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A technique for avoiding infinite integrals in the calculation of the one-loop diagram contribution to the vacuum polarization component of an atomic energy level is presented. This makes renormalization unnecessary. Infinite integrals do not occur because, as it is shown, no delta functions are required for the Green’s functions. Thus there are none to overlap. This procedure is shown to produ...
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We present an up-to-date survey of theoretical concepts and results in the field of one-dimensional magnetism and of their relevance to experiments and real materials. Main emphasis of the chapter is on quantum phenomena in models of localized spins with isotropic exchange and additional interactions from anisotropy and external magnetic fields. Three sections deal with the main classes of mode...
متن کاملLup-20(29)-en-28-ol-3-one (betulone)
The asymmetric unit of the title compound, C30H48O2, contains two independent mol-ecules, the main difference between them being that the isopropenyl group is rotated by approximately 180°. In each mol-ecule, the fused six-membered rings have chair-chair-chair-chair conformations and the cyclo-pentane ring adopts an envelope conformation with the C atom bearing the hy-droxy-methyl group as the ...
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ژورنال
عنوان ژورنال: Acta Crystallographica Section E Structure Reports Online
سال: 2009
ISSN: 1600-5368
DOI: 10.1107/s1600536809013853