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Cyclohexanone Derivatives (cyclohexanone + derivative)
Selected AbstractsThe Effect of ,-Cyclodextrin on the Diastereoselective NaBH4 Reduction of Cyclohexanone Derivatives.CHEMINFORM, Issue 52 2006Myung Soo Seo Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Formation of Highly Substituted Chiral Cyclohexanone Derivatives Using a Tandem Conjugate Addition/Cyclization.CHEMINFORM, Issue 8 2005David W. Jeffery Abstract For Abstract see ChemInform Abstract in Full Text. [source] A New, Efficient and Stereoselective Synthesis of Tricyclic and Tetracyclic Compounds by Samarium Diiodide Induced Cyclisations of Naphthyl-Substituted Arylketones,An Easy Access to Steroid-Like SkeletonsCHEMISTRY - A EUROPEAN JOURNAL, Issue 21 2007Francesca Aulenta Dr. Abstract In this report, we present the application of samarium diiodide induced cyclisations of naphthyl-substituted ketones towards an easy and stereoselective access to tri- and tetracyclic-functionalised compounds. Typical naphthalene derivatives were studied to investigate the scope and limitations of this novel cyclisation process. The model substrates studied demonstrate that the samarium ketyl cyclisations are essentially restricted to the formation of six-membered rings. The diastereoselectivity of these reactions is strongly influenced by the connection of the alkyl side chain to the naphthalene core. ,-Naphth-1-yl-substituted ketones furnished cyclisation products, such as 17 or 22,26, as single diastereomers, whereas ,-naphth-2-yl-substituted precursors gave mixtures of diastereomers,as demonstrated by the conversion of model compound 10 into tricyclic products 18,a/18,b, or that of cyclohexanone derivative 33 into tetracyclic diastereomers 34,a/34,b. Cyclic ketones as ketyl precursors furnished steroid-like tetracyclic skeletons; however, due to the cis/cis fusion of rings B/C and C/D these products have an "unnatural" bowl-like shape. Several of the cyclisation products have been identified by X-ray analyses, which not only proved the constitutions, but also the relative configurations and the preferred conformations. Steroid analogue 23 was subjected to subsequent transformations, which demonstrate that the styrene-like double bond of such compounds can be used for further structural diversification. First attempts to synthesise related azasteroids by incorporating nitrogen atoms into the ketone moiety are also reported. Thus, pyrrolidine derivatives 44 and 47 as well as piperidine derivatives 50 and 52 were subjected to samarium diiodide induced cyclisations. The expected tetracyclic products 48, 49,a/49,b, 51 and 53,a/53,b were obtained in moderate to good yields. The stereoselectivities observed follow the rules already established for the all-carbon precursors. The resulting products, bearing a nitrogen atom in ring D, are interesting azasteroid analogues with "unnatural" configuration. [source] Synthesis of Enantiopure 1-Azaspiro[4.5]decanes by Iodoaminocyclization of AllylaminocyclohexanesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 18 2007Faïza Diaba Abstract The 5- endo iodine-promoted ring closure of 4-allyl-4-(alkylamino)cyclohexanone derivatives gives the corresponding 1-azaspiro[4.5]decanes in good yields. The reaction was tested with enantiopure homoallylamines to evaluate the diastereoselectivity of the process and to provide a route for possible intermediates to the natural products embodying this azabicyclic ring.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] ChemInform Abstract: Rh(I)-Catalyzed [(3 + 2) + 1] Cycloaddition of 1-Yne/Ene-vinylcyclopropanes and CO: Homologous Pauson,Khand Reaction and Total Synthesis of (.+-.)-,-Agarofuran (XIII).CHEMINFORM, Issue 41 2010Lei Jiao Abstract The novel reaction is developed to prepare bicyclic cyclohexanone derivatives. [source] | ||||||||||