Stereochemistry of hydrogenation of 19-substituted 5α-cholestan-3-ones
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چکیده
منابع مشابه
3β-Chloro-5α-cholestan-6-one
The asymmetric unit of the title compound, C(27)H(45)ClO, consists of two crystallographically independent mol-ecules. In both mol-ecules, the three cyclo-hexane rings in the steroid fused-ring systems adopt chair conformations, while the cyclo-pentane ring adopts a half-chair conformation in one mol-ecule and an envelope conformation in the other. In the crystal, the mol-ecules are linked into...
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A variety of 3-substituted benzisoxazoles were reduced with hydrogen using the chiral ruthenium catalyst, {RuCl(p-cymene)[(R,R)-(S,S)-PhTRAP]}Cl. The ruthenium-catalyzed hydrogenation proceeded in high yield in the presence of an acylating agent, affording α-substituted o-hydroxybenzylamines with up to 57% ee. In the catalytic transformation, the N-O bond of the benzisoxazole substrate is reduc...
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The asymmetric unit of the title compound, C(32)H(51)N(3)O(3), consists of two crystallographically independent mol-ecules, A and B; the 2-methyl-pentane group of mol-ecule A and the propane group of mol-ecule B are each disordered over two sets of sites, with refined site-occupancies of 0.825 (5):0.175 (5) and 0.630 (18):0.370 (18), respectively. In both mol-ecules, the three cyclo-hexane ring...
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Pyrrolizin-3-ones (e.g. 1) can be easily hydrogenated to their hexahydro (pyrrolizidin-3-one) derivatives in the presence of heterogeneous catalysts. Good diastereoselectivity (up to >97:3, depending on catalysts and solvent) can be achieved if the pyrrolizin-3-one is substituted at the 1- (or 7-) position(s), but the selectivity is reduced if both positions are substituted. Subsequent deoxygen...
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ژورنال
عنوان ژورنال: Canadian Journal of Chemistry
سال: 1969
ISSN: 0008-4042,1480-3291
DOI: 10.1139/v69-247