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Few Steps (few + step)
Selected AbstractsSynthesis of 3,-Deoxyribolactones using a Hydrolysis-Induced Lactonization Cascade Reaction of Epoxy CyanohydrinsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 8 2008Danielle J. Vugts Abstract The synthesis of 3,-deoxyribolactones was accomplished in a few steps from the commercially available 3-decyn-1-ol in 44,% overall yield. The key transformation comprises a one-pot four-reaction hydrolysis-induced lactonization cascade. The strategy was employed to efficiently access optically active 5,-chloro-3,-deoxyribolactones. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Synthesis of Novel Di- and Trisaccharide Mimetics with Non-Glycosidic Amino BridgesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 7 2007Janna Neumann Abstract Synthesis of novel di- and trisaccharides using enzymatic glycosylation, Dess,Martin oxidation and reductive amination allows rapid access to the target structures. Thus, a novel class of glycomimetics was obtained having nitrogen inserted as bridging atom between two non-anomeric positions. Novel di- and trisaccharide mimetics were designed using N -acetylglucosamine as a basis structure. A third monosaccharide unit was attached via an unnatural sugar,sugar bond without participation of the anomeric center. Their synthesis, proceeding via oxidation, glycosylation and reductive amination, required only a few steps, thus allowing rapid access to the target structures. Generation of the novel pseudo-disaccharide was achieved by Dess,Martin oxidation and a subsequent reductive amination. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Access to Any Site-Directed Isotopomer of Methionine, Selenomethionine, Cysteine, and Selenocysteine , Use of Simple, Efficient Modular Synthetic Reaction Schemes for Isotope IncorporationEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 13 2004Arjan H. G. Siebum Abstract Simple modular reaction schemes that allow access to any isotopomer of protected serine and homoserine have been worked out. These systems could be simply converted into cysteine, selenocysteine, homocysteine, homoselenocysteine, the essential amino acid methionine, and selenomethionine by Mitsunobu chemistry. These sulfur- and selenium-containing amino acids fulfil many essential roles in the living organism. In addition, homoserine could be converted in a few steps into optically active L -vinylglycine. As well as the stable isotopes 13C, 15N, 17O, and 18O, the radioactive isotopes of sulfur, selenium and carbon can also be easily introduced in a site-directed fashion. In view of the wide scope of the Mitsunobu reaction, we feel that many more important systems with the carbon skeleton of serine and homoserine should be preparable through this basic chemistry in any site-directed isotopically labeled form. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source] Synthesis and biological evaluation of structural variants of carbazoquinocin CJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 3 2003Alparslan Aygün Some new structural variants of the alkaloid carbazoquinocin C were synthesized in a few steps with good to excellent yields. The key step comprises a cyclisation reaction of appropriate 2-vinylindoles with oxalyl chloride. The carbazole-3,4-quinones are able to trap oxygen-centred radicals. In some biological/biochemical assays some of these compounds exhibit extraordinary results including inhibition of cyclooxygenase-1 and 5-lipoxygenase in the ,M-range. Moreover some of the carbazoquinocin C-variants inhibit significant oxidative damage of cellular DNA in nM-range. [source] Convenient Synthesis of Bicyclic Carbohydrate 1,2-Lactones and Their Stereoselective Opening to 1-Functionalized Glucose DerivativesCHEMISTRY - A EUROPEAN JOURNAL, Issue 1 2009Jian Yin Closed and re-opened for business: C-2 branched carbohydrates 1 cyclize under conditions of decarboxylation to the hitherto unknown carbohydrate 1,2-lactones 2 in high yields. The gluco isomer can be opened at the anomeric position with various nuceophiles in the presence of Sc(OTf)3, which allows the stereoselective synthesis of 1-functionalized glucose derivatives 3. Thus, 1,2- bis-C -branched saccharides become available in only a few steps starting from glycals. [source] | ||||||||||