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Stereochemical Aspects (stereochemical + aspect)
Selected AbstractsSynthesis and Stereochemical Aspects of 2,6-Disubstituted Perhydroazulenes , Core Units for a New Class of Liquid Crystalline MaterialsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 24 2006Zakir Hussain Abstract A novel approach for the synthesis of cis/trans -fused perhydroazulenes 13,19 is reported. The stereochemistry of the derivatives of carbene addition products 9a,c/20,22, of the 2,6-disubstituted perhydroazulenes 12a,c/23,25, and that of compounds 26,27 has been studied by single-crystal X-ray crystallography. The hydrogenation of the tropylidene to the perhydroazulene skeleton under various conditions is described. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] Regio- and Stereochemical Aspects in Synthesis of 2-Allyl Derivatives of Glycolic, Mandelic and Lactic Acids and Their Iodocyclizations to 3-Hydroxy-3,4-dihydrofuran-2(5H)-ones.CHEMINFORM, Issue 49 2005Pervinder Kaur Abstract For Abstract see ChemInform Abstract in Full Text. [source] Mechanistic and Stereochemical Aspects of the Asymmetric Cyclocarbonylation of 1,6-Enynes with Rhodium Catalysts.CHEMINFORM, Issue 12 2005Thomas M. Schmid Abstract For Abstract see ChemInform Abstract in Full Text. [source] Iridium-Catalyzed Allylic Substitution: Stereochemical Aspects and Isolation of IrIII Complexes Related to the Catalytic Cycle.CHEMINFORM, Issue 4 2003Bjoern Bartels Abstract For Abstract see ChemInform Abstract in Full Text. [source] Main Structural and Stereochemical Aspects of the Antiherpetic Activity of Nonahydroxyterphenoyl-Containing C -Glycosidic EllagitanninsCHEMISTRY & BIODIVERSITY, Issue 2 2004Stéphane Quideau Antiherpetic evaluation of five nonahydroxyterphenoyl-containing C -glycosidic ellagitannins, castalagin (1), vescalagin (2), grandinin (3), roburin B (5), and roburin D (7), was performed in cultured cells against four HSV-1 and HSV-2 strains, two of which were resistant to Acyclovir. All five ellagitannins displayed significant anti-HSV activities against the Acyclovir -resistant mutants, but the monomeric structures 1,3 were more active than the dimers 5 and 7. Vescalagin (2) stands out among the five congeners tested as the most potent and selective inhibitor, with an IC50 value in the subfemtomolar range and a selectivity index 5×105 times higher than that of Acyclovir. Molecular modeling was used to provide a rationale for the surprisingly lower activity profile of its epimer castalagin (1). These ellagitannins have promising potential as novel inhibitors in the search for non-nucleoside drugs active against Acyclovir -resistant herpes viruses. [source] In the Quest for a Virtual Pseudo Receptor for Sandalwood-Like Odorants.CHEMISTRY & BIODIVERSITY, Issue 7 2004Based on similarities between naturally occurring (,)-(Z)- , - or (+)-(Z)- , -santalol ((,)- 1 or (+)- 2, resp.) and the reversed (E)-configured synthetic derivatives from campholenal (7a), a simple model A was developed. Besides reconciliation of this stereochemical aspect, this initial model also tentatively explained the enantiodiscriminations as well as the large spectra of distances separating the OH function from the lipophilic quaternary center(s) reported for different classes of substrates. Evolution, modifications, and refinement of this imperfect model allied with the research for alternative possibilities are illustrated, along with a historical guideline, in the light of olfactively challenging synthetic seco-substructures as well as literature reports. Despite evolution of the inadequate model A and a plausible interpretation of the lipophilic part, the topological positions of the OH function and its vicinal alkyl substituent could nevertheless not be fully ascertained by this approach. This apparently inconclusive empirical concept prompted us to turn our attention towards a computerized methodology, which will constitute the second and third part of this study. [source] | ||||||||||