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Heinz Heimgartner - One of the best experts on this subject based on the ideXlab platform.
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Optisch aktive 3‐Amino‐2H‐Azirine als Bausteine für enantiomerenreine αα‐disubstituierte α‐Aminosäuren: Synthese von Isovalin‐Synthonen und Einbau in ein Trichotoxin‐A‐50‐Segment
Helvetica Chimica Acta, 1996Co-Authors: Christoph Bucher, Heinz HeimgartnerAbstract:Optically Active 3-Amino-2H-Azirines as Synthons for Enantiomerically Pure αα-Disubstiuted α-Amino Acids: Syntheses of Isovaline Synthons and a Segment of Trichotoxin A-50 The synthesis of a novel 3-amino-2-methyl-2-[2-(phenylsulfonyl)ethyl]-2H-Azirine Derivative 12 with a chiral substituent at the amino group is described. Chromatographic separation of the diastereoisomer mixture gave pure diastereoisomers which, after an electrochemical cleavage of the phenylsulfonyl group, yielded the (S)- and (R)-isovalin (Iva) synthons 13a and 13b, respectively. The absolute configuration of the precursor molecule 12b was established by X-ray crystallography. The Iva synthons were successfully used in the synthesis of the C-terminal pentapeptide Z-Leu-Aib-(R)-Iva-Gln-Valol of the peptaibole Trichotoxin A-50 and its epimer.
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Optisch aktive 3-Amino-2H-Azirine als Bausteine für enantiomerenreine alpha,alpha-disubstituierte alpha-Aminosäuren: Synthese des alpha-Methylphenylalanin-Synthons and Einbau in Modell-Peptide
Helvetica Chimica Acta, 1995Co-Authors: Christoph Bucher, Anthony Linden, Heinz HeimgartnerAbstract:Optically Active 3-Amino-2H-Azirines as Synthons for Enantiomerically Pure alpha,alpha-Disubstituted alpha-Amino Acids: Synthesis of the alpha-Methylphenylalanine Synthons and Some Model Peptides The synthesis of a novel 2-benzyl-2-methyl-3-amino-2H-Azirine Derivative with a chiral amino group is described. Chromatographic separation of the diastereoisomer mixture yielded the pure diastereoisomers 9a and 9b (Scheme 4 ) which are the D- and L-2-methylphenylalanine ((alpha-Me)Phe) synthons, respectively. The reaction of 9a and 9b with thiobenzoic acid and with Z-leucine yielded the monothiodiamides 10a and 10b (Scheme 5 ) and the dipeptide Derivatives 11a and 11b (Scheme 6), respectively. Methanolysis of 11b yielded 12b. The absolute configuration of 10a was established by X-ray crystallography. The absolute configuration of (alpha-Me)Phe in 12b has been deduced from the known configuration of L-leucine.
Christoph Bucher - One of the best experts on this subject based on the ideXlab platform.
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Optisch aktive 3‐Amino‐2H‐Azirine als Bausteine für enantiomerenreine αα‐disubstituierte α‐Aminosäuren: Synthese von Isovalin‐Synthonen und Einbau in ein Trichotoxin‐A‐50‐Segment
Helvetica Chimica Acta, 1996Co-Authors: Christoph Bucher, Heinz HeimgartnerAbstract:Optically Active 3-Amino-2H-Azirines as Synthons for Enantiomerically Pure αα-Disubstiuted α-Amino Acids: Syntheses of Isovaline Synthons and a Segment of Trichotoxin A-50 The synthesis of a novel 3-amino-2-methyl-2-[2-(phenylsulfonyl)ethyl]-2H-Azirine Derivative 12 with a chiral substituent at the amino group is described. Chromatographic separation of the diastereoisomer mixture gave pure diastereoisomers which, after an electrochemical cleavage of the phenylsulfonyl group, yielded the (S)- and (R)-isovalin (Iva) synthons 13a and 13b, respectively. The absolute configuration of the precursor molecule 12b was established by X-ray crystallography. The Iva synthons were successfully used in the synthesis of the C-terminal pentapeptide Z-Leu-Aib-(R)-Iva-Gln-Valol of the peptaibole Trichotoxin A-50 and its epimer.
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Optisch aktive 3-Amino-2H-Azirine als Bausteine für enantiomerenreine alpha,alpha-disubstituierte alpha-Aminosäuren: Synthese des alpha-Methylphenylalanin-Synthons and Einbau in Modell-Peptide
Helvetica Chimica Acta, 1995Co-Authors: Christoph Bucher, Anthony Linden, Heinz HeimgartnerAbstract:Optically Active 3-Amino-2H-Azirines as Synthons for Enantiomerically Pure alpha,alpha-Disubstituted alpha-Amino Acids: Synthesis of the alpha-Methylphenylalanine Synthons and Some Model Peptides The synthesis of a novel 2-benzyl-2-methyl-3-amino-2H-Azirine Derivative with a chiral amino group is described. Chromatographic separation of the diastereoisomer mixture yielded the pure diastereoisomers 9a and 9b (Scheme 4 ) which are the D- and L-2-methylphenylalanine ((alpha-Me)Phe) synthons, respectively. The reaction of 9a and 9b with thiobenzoic acid and with Z-leucine yielded the monothiodiamides 10a and 10b (Scheme 5 ) and the dipeptide Derivatives 11a and 11b (Scheme 6), respectively. Methanolysis of 11b yielded 12b. The absolute configuration of 10a was established by X-ray crystallography. The absolute configuration of (alpha-Me)Phe in 12b has been deduced from the known configuration of L-leucine.
Anthony Linden - One of the best experts on this subject based on the ideXlab platform.
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Optisch aktive 3-Amino-2H-Azirine als Bausteine für enantiomerenreine alpha,alpha-disubstituierte alpha-Aminosäuren: Synthese des alpha-Methylphenylalanin-Synthons and Einbau in Modell-Peptide
Helvetica Chimica Acta, 1995Co-Authors: Christoph Bucher, Anthony Linden, Heinz HeimgartnerAbstract:Optically Active 3-Amino-2H-Azirines as Synthons for Enantiomerically Pure alpha,alpha-Disubstituted alpha-Amino Acids: Synthesis of the alpha-Methylphenylalanine Synthons and Some Model Peptides The synthesis of a novel 2-benzyl-2-methyl-3-amino-2H-Azirine Derivative with a chiral amino group is described. Chromatographic separation of the diastereoisomer mixture yielded the pure diastereoisomers 9a and 9b (Scheme 4 ) which are the D- and L-2-methylphenylalanine ((alpha-Me)Phe) synthons, respectively. The reaction of 9a and 9b with thiobenzoic acid and with Z-leucine yielded the monothiodiamides 10a and 10b (Scheme 5 ) and the dipeptide Derivatives 11a and 11b (Scheme 6), respectively. Methanolysis of 11b yielded 12b. The absolute configuration of 10a was established by X-ray crystallography. The absolute configuration of (alpha-Me)Phe in 12b has been deduced from the known configuration of L-leucine.
