13649-97-3Relevant academic research and scientific papers
Study of the effect of the nature of the side chain in esters of α-amino acids on the diastereoselectivity of condensation with 5(4H)-oxazolone in the synthesis of dipeptides with N-terminal N-acetylphenylalanine
Krasnov,Zhdanova,Solieva,Sadretdinova,Bukrina,Demin,Levit,Ezhikova,Kodess
, p. 1331 - 1334 (2007/10/03)
Conditions for fast racemization of 5(4H)-oxazolones prepared from N-acylphenylalanine were found. Reactions of 4-benzyl-2-methyl-5(4H)-oxazolone with amino acid esters proceed diastereoselectively to give predominantly dipeptides comprising R-phenylalanine. The diastereoselectivity increases with complication of the structure of the side chain in the amino acid esters.
A mild and efficient protocol for the conversion of carboxylic acids to olefins by a catalytic decarbonylative elimination reaction
Goossen, Lukas J.,Rodriguez, Nuria
, p. 724 - 725 (2007/10/03)
A new method for the conversion of aliphatic carboxylic acids to olefins under unprecedented mild conditions is disclosed, wherein the carboxylic acids are converted in situ with pivalic anhydride to the mixed anhydrides, which regioselectively add to a PdCl2-DPE-Phos catalyst. At a temperature of only 110°C, smooth decarbonylation and β-hydride elimination occur, and the corresponding olefins along with CO, CO2 and pivalic acid are liberated.
ASYMMETRIC SYNTHESIS OF AMINO ACIDS VIA THE CATALYTIC REDUCTION OF SUBSTITUTED ACYLAMINOACRYLIC ACID AZLACTONES. 26. AMINOLYSIS OF 2-METHYL-4-BENZYLOXAZOLIN-5-ONE UPON REACTION WITH S-PHENYLALANINE DERIVATIVES
Lyubeznova, M. R.,Karpeiskaya, E. I.,Klabunovskii, E. I.,Koreshkov, Yu. D.,Lutsenko, A. I.,Lubuzh, E. D.
, p. 731 - 737 (2007/10/02)
The kinetics of aminolysis and racemization of 2-methyl-4-benzyloxazolin-5-one upon reaction with S-phenylalanine methyl ester have been studied in dimethoxyethane solvent.The rates of aminolysis and racemization are comparable.Addition of an achiral component, namely Et3N, to the reaction mixture, however, dramatically increases the rate of racemization.The presence of Et3N also increases the ratio of rate constants for the formation of RS- and SS-diastereomers, which determines the reaction stereoselectivity.
STUDIES ON THE KINETICS OF RACEMIZATION OF 2,4-DISUBSTITUTED-5(4H)-OXAZOLONES
Slebioda, Marek,St-Amand, Marc A.,Chen, Francis M. F.,Benoiton, N. Leo
, p. 2540 - 2544 (2007/10/02)
The kinetics of racemization of 2,4-disubstituted-5(4H)-oxazolones obtained from N-acetyl, N-benzoyl, and N-benzyloxycarbonylglycyl-L-leucine, -valine, and -phenylalanine have been studied in several solvents alone and in the presence of tertiary amines.T
Heterocycles as Masked Diamide/Dipeptide Equivalents. Formation and Reactions of Substituted 5-(Acylamino)oxazoles as Intermediates en route to the Cyclopeptide Alkaloids
Lipshutz, Bruce H.,Hungate, Randall W.,NcCarthy, Keith E.
, p. 7703 - 7713 (2007/10/02)
A variety of novel 2,4-dialkyl-5-(acylamino)oxazoles have been prepared by using either amide nitriles or diamides/dipeptides as starting materials.Ring closure calls for the use of trifluoroacetic acid/trifluoroacetic acid anhydride or an acid halide in
