16679-94-0Relevant academic research and scientific papers
Cleavage of benzyloxycarbonyl-5-oxazolidinones to α-benzyloxycarbonylamino-α-alkyl esters by alcohols and sodium hydrogen carbonate
Allevi, Pietro,Cighetti, Giuliana,Anastasia, Mario
, p. 5319 - 5321 (2007/10/03)
The reaction of benzyloxycarbonyl-5-oxazolidinones with alcohols and sodium hydrogen carbonate to afford the corresponding benzyloxycarbonyl esters is described.
A simple and efficient procedure for the synthesis of optically active 4-methoxy-α-methylphenylethylamine from tyrosine
Kohno, Harumichi,Iwakuma, Takeo,Yamada, Koichiro
, p. 1935 - 1945 (2007/10/03)
Optically active 4-methoxy-α-methylphenylethylamine (1), a useful chiral building block in medicinal chemistry, was synthesized from L- or D- tyrosine by using a simple and efficient procedure via one-pot zinc reduction of the corresponding O-tosylate (4) in the presence of H2O and NaI in pure form.
An Improved Preparation of Oxazolidin-2-one Chiral Auxiliaries
Sudharshan, Manjula,Hultin, Philip G.
, p. 171 - 172 (2007/10/03)
Reduction of carbamate-blocked amino esters by lithium borohydride (made in situ from sodium borohydride and lithium iodide) forms chiral 4-substituted oxazolidin-2-ones directly. The presence of iodide in the reaction mixture appears to promote the cyclization of the intermediate alkoxyborohydride. This provides a route to these important chiral auxiliaries, employing less hazardous reagents and simpler reaction conditions than do most existing methods.
A Formal Total Synthesis of the ACE Inhibitor K-13. An Application of Arene-Ruthenium Chemistry to Complex Chemical Synthesis
Pearson, Anthony J.,Lee, Kieseung
, p. 2304 - 2313 (2007/10/02)
Stoichiometric ruthenium activation of 4-chlorophenylalanine derivatives toward nucleophilic substitution, using phenoxide nucleophiles that are derived from protected dipeptides, allowed the formation of isodityrosine derivatives that are synthetic precursors to the ACE inhibitor K-13.An evaluation of carboxyl blocking groups revealed that a 2-bromoethyl ester is the most useful in terms of its compatibility with ruthenium complexation and subsequent nucleophile addition but that its removal is problematic.Conversion to iodoethyl ester using Finkelstein reaction conditions, in the presence of the peptide and amino acid functionality, provided a solution to this problem, since the iodoethyl group was easily removed on treatment with samarium diiodide.
PAPAIN-ASSISTED RESOLUTION OF NATURAL AND XENOBIOTIC α-AMINO ACIDS
Moriniere, J. L.,Danree, B.,Lemoine, J.,Guy, A.
, p. 441 - 444 (2007/10/02)
A new and convenient method for the preparation of pure enantiomers of α-amino acids is described.Industrial papain, catalyzes the synthesis of L-Z-amino acid ethyl esters in ethanolic medium, with good yields.These esters are obtained from DL-Z-amino acids with 100percent optical purity.Unreactive D-Z-amino acids are readily isolated from reaction medium.Physical constants of natural and xenobiotic L-Z-amino acid esters and D-Z-amino acids are described.
Conventional Synthesis of Thymopoietin 32-36 (TP 5) Using the 1-(1-Adamantyl)-1-methyletoxycarbonyl Group
Heinzel, Wolfgang,Kronbach, Thomas,Voelter, Wolfgang
, p. 1652 - 1658 (2007/10/02)
A synthesis of high yields of TP 5 is described.The α-amino functions were blocked by the acid-labile 1-(1-adamantyl)-1-methylethoxycarbonyl-(Adpoc)group.The Adpoc group is cleaved under mild acidolytic conditions with 3percent TFA in CH2Cl2 while the tert-butyl residues remained intact.This selective cleavage of the Adpoc group compared with the Boc and tert-butyl residues allows new strategies for the synthesis of large peptides. - Keywords: Adpoc, Amino acids, Thymopoietin
