- Rational synthesis of all the four stereoisomers of 3-(trans-2- aminocyclopropyl)alanine
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All the four stereoisomers of 3-(trans-2-aminocyclopropyl)alanine - a key constituent of the potential antitumor agent belactosin A -were prepared by simple catalytic hydrogenation of (2S,1′S,2′S)-, (2S,1′R,2′R)-, (2R,1′R,2′R)-, and (2R,1′S, 2′S)-3-(trans-2-nitro-cyclopropyl)alanines in 95, 93, 91 and 92% yields, respectively.
- Larionov, Oleg V.,Kozhushkov, Sergei I.,Brandl, Melanie,De Meijere, Armin
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- Chiral Receptors for Lysine Based on Covalently Linked Bis- and Tris-binaphthylphosphoric Acids
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The synthesis and application of three chiral receptors based on the covalent linkage of 1,1′-binaphthylphosphoric acids is reported. The binding of the lysine enantiomers to the chiral receptors was investigated by DOSY-NMR and NMR titrations, revealing that the bisphosphoric acid 1d acts as a highly stereoselective receptor for binding of d-lysine.
- Octa-Smolin, Frescilia,Thiele, Maike,Yadav, Rohan,Platzek, André,Clever, Guido H.,Niemeyer, Jochen
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supporting information
p. 6153 - 6156
(2018/10/05)
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- Process for racemizing optically active α-amino acids or a salt thereof
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DL-α-amino acids or a salt thereof can be obtained by racemizing an optically active α-amino acid or a salt thereof in the presence of an aliphatic acid and an aldehyde.
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- Method for the Racemization of Optically Active Amino Acids
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A practical method for the racemization of optically active amino acids has been developed.A wide variety of optically active α-amino acids, including neutral amino acids, acidic amino acids, basic amino acids, and imino acids, could be racemized by heating in a medium of acetic acid at 80-100 deg C for 1 h in the presence of 0.05 molar equiv of an aliphatic or an aromatic aldehyde.The factors influencing the racemization were investigated.Phenylglycine, (p-hydroxyphenyl)glycine, and serine could be racemized without complete dissolution of the optically active isomers.Thus, isolation of the racemic modification was easily achieved by simple filtration of the racemic modification suspended in the reaction mixture.The mechanism of the racemization is discussed.
- Yamada, Shigeki,Hongo, Chikara,Yoshioka, Ryuzo,Chibata, Ichiro
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p. 843 - 846
(2007/10/02)
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