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Showing 1 to 8 of 8 for “"Hydrazon-Methode"”.
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Asymmetrische Synthese von Sordidin, 7-epi-Sordidin und von Polyoeinheiten mit quartären Stereozentren
… has been achieved. Starting from dioxanone RAMP-hydrazone the desired C-7 epimers were prepared in 39% overall yield as a 1.5: 1 diastereomeric mixture over 14 steps. The epimers could be separated by preparative GC and thus, each of them could be obtained in high diastereomeric and enantiomeric …
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1,3-Aminoalkohole als Bausteine in der asymmetrischen Synthese von Azetidinen, Azetidincarbonsäuren und Piperidin-3-olen
… in good overall yields starting from SAMP-hydrazones is described. Virtually stereoisomerically pure differently N,O-protected 1,3-amino alcohols were prepared as intermediates. By using the phenyl moiety as a synthetic equivalent of the carboxylic acid function, this protocol could also be …
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Asymmetrische Synthese von hoch substituierten delta -Lactonen : Synthese der Prelactone B und V, von Simplacton B und von Massoialacton
… were carried out in this work. The RAMP-hydrazone of 2,2-dimethyl-1,3-dioxan-5-one was chosen as starting material for the synthesis of the 4-hydroxy-5,6-alkyl and 4-hydroxy-5-alkyl substituted lactones (prelactones und simplacton B). Key step of this six step synthesis was the …
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Totalsynthese von (+)-2-epi-Deoxoprosopinin und neue Hydrazin-Harze für die organische Festphasensynthese
… of a dodecyl nucleophile to an aldehyde-SAMP hydrazone and the a -alkylation of 2,2-dimethyl-1,3-dioxan-5-one SAMP hydrazone were employed to generate two of the three stereogenic centers. Creation of the third stereogenic center was achieved in a domino deprotection/cyclisation/reduction …
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Asymmetric synthesis of lignans and of α-heteroaryl)alkylamines employing the SAMP-/RAMP-hydrazone method
… of heteroarenyllithium species to SAMP-/RAMP-hydrazones, has been developed. Moreover the novel methodology was successfully applied to the synthesis of biologically interesting compounds such as a-aminoacids and b-aminosulfones.
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Versuche zur ersten Totalsynthese des Aglycons der Cripowelline A und B und erste asymmetrische Synthese von Tropional
… enantiomers of Tropional based on the SAMP/RAMP-hydrazone method developed by Enders et al. Starting from the enantiomerically pure propanale hydrazones the desired alpha-alkylated hydrazones could be obtained in yields greater than 70% by deprotonation with LDA at -100øC. Subsequent cleavage to …
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Asymmetrische Totalsynthese von 16(S)-Iloprost und 3-Oxa-16(S)-Iloprost mittels der Azoen-Strategie
… azoene with formation of the corresponding hydrazone in 84% yield. The E-Isomer of 16S-iloprost was obtained in 11 steps with an overall yield of 5%. 3-Oxa-16S-iloprost was successfully prepared by using an asymmetric HWE-reaction with a chiral phosphonate as a key step in an overall yield …