Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 7 of 7 for “"beta-amino acids"”.
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The preparation of racemic and optically active beta-amino-acids and their utilisation in peptide formation.
B-Amino acids are being isolated from biologically active peptide antibiotics with increasing frequency nowadays. Recognition of the importance of these amino acids, has led to their incorporation into synthetic peptide analogues and into polymers. The main part of this thesis reports the …
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Delta-Hydroxy-beta,beta-disubstituierte-beta-Aminosäuren: asymmetrische Synthese und Überführung in Dipeptide
… thesis describes a pathway for the synthesis of beta-mono- and beta-disubstituted delta-hydroxy-beta-amino acids having three contiguous stereogenic centers and the conversion of these molecules to dipeptides. The advantages of the herein described synthetic strategy relies on the extended …
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1,3-Aminoalkohole als Bausteine in der asymmetrischen Synthese von Azetidinen, Azetidincarbonsäuren und Piperidin-3-olen
… azetidines and especially azetidine carboxylic acids in the literature.A versatile and efficient asymmetric synthesis of substituted azetidines with excellent diastereomeric and enantiomeric excesses (de = 93-99%, ee = 96-99%) in good overall yields starting from SAMP-hydrazones is described. …
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Asymmetric anhydride opening : optimization and applications
… by the preparation of optically active beta-amino acids through a reaction sequence involving a Curtius degradation as a key step. Their complete deprotection could be accomplished in a single step by simple hydrogenation enabling the isolation of rather sensitive products. As an …
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Stereoselective synthesis of piperidines
… enol ethers iii. These were cleaved to give amino ketones iv. The switch in the nature of the resin from acid-stable to acid-labile is key to the purity of the amino ketones iv, as during cleavage only the acid-sensitive enol ethers iii are cleaved, leaving the unreacted esters i on the …
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Katalytische, enantioselektive Synthesen von Diarylmethanolen und Allylalkoholen
… asymmetric phenyl transfer, were N-substituted beta-amino alcohol derivatives, including either cis- or trans-beta-aminocyclohexanols and an open chain pyrrolinyl amino alcohol. The products were attained in good yields (73-99%) with enantioselectivities of between 6% and 87% ee. Triphenylborane …