Experiments on the acid-stability of γ-benzyl ester protecting groups in the synthesis pf L-glutamyl peptides

1971 ◽  
Vol 24 (12) ◽  
pp. 2739 ◽  
Author(s):  
FHC Stewart
Keyword(s):  
Benzyl Ester ◽  
Protecting Groups ◽  
Acid Stability

Preparation and some biological properties of N-acetylmuramyl-alanyl-D-isoglutamine (MDP) analogues

1982 ◽  
Vol 47 (11) ◽  
pp. 2989-2995 ◽  
Author(s):  
Milan Zaoral ◽  
Jan Ježek ◽  
Jiří Rotta
Keyword(s):  
Biological Properties ◽  
Benzyl Ester ◽  
Protecting Groups

The condensation of 1-α-O-benzyl-4,6-O-benzylidene-N-acetylgalactomuramic acid (I), 1-α-O-benzyl-4,6-O-benzylidene-N-acetylallomuramic acid (VIII), and 1-α-O-benzyl-4,6-O-benzylidene-N-acetylnorallomuramic acid (XI) with alanyl-D-isoglutamine benzyl ester afforded 1-α-O-benzyl-4,6-O-benzylidene-N-acetylgalactomuramyl-alanyl-D-isoglutamine benzyl ester (XII), 1-α-O-benzyl-4,6-O-benzylidene-N-acetylallomuramyl-alanyl-D-isoglutamine benzyl ester (XIII) and 1-α-O-benzyl-4,6-O-benzylidene-N-acetylnorallomuramyl-alanyl-D-isoglutamine benzyl ester (XIV). Protecting groups were removed from XII-XIV and N-acetylgalactomuramyl-alanyl-D-isoglutamine (XV), N-acetylallomuramyl-alanyl-D-isoglutamine (XVI), and N-acetylnorallomuramyl-alanyl-D-isoglutamine (XVII) were obtained. XV-XVII showed lower pyrogenic and immunoadjuvant effect than N-acetylmuramyl-alanyl-D-isoglutamine.

scholarly journals Syntheses of penicillin N, [6 α-3H]penicillin N and [10-14C,6 α-3H]penicillin N

1980 ◽  
Vol 186 (3) ◽  
pp. 881-887 ◽  
Author(s):  
J E Baldwin ◽  
S R Herchen ◽  
P D Singh
Keyword(s):  
Glutamic Acid ◽  
Benzyl Ester ◽  
Protecting Groups ◽  
Acid Salt ◽  
Schiff’S Base ◽  
Free Amine ◽  
Penicillanic Acid ◽  
Base Derivative

1. Penicillin N was synthesized by coupling alpha-amino-alpha-p-nitrobenzyl-N-p-nitro-benzyloxycarbonyl-D-adipate with 6-aminopenicillanic acid benzyl ester, followed by removal of the protecting groups through hydrogenolysis. 2. alpha-Amino-alpha-p-nitrobenzyl-N-p-nitrobenzyloxycarbonyl-D-[5-14C]adipate was prepared by treating alpha-p-nitrobenzyl-N-p-nitrobenzyloxycarbonyl-D-glutamic acid with [14C]diazomethane followed by rearrangement with silver trifluoromethanesulphonate. 3. Coupling of alpha-amino-alpha-p-nitrobenzyl-N-p-nitrobenzyloxycarbonyl-D-[5-14C]adipate with 6-aminopenicillanic acid benzyl ester gave triprotected [10-14C]penicillin N. 4. 3H was introduced at C-6 of the Schiff's base derivative (10) by oxidation followed by reduction with NaB3H4. 5. The so-derived (6 alpha-3H)-labelled Schiff's base was hydrolysed to give 6-amino [6 alpha-3H]penicillanic acid benzyl ester p-toluenesulphonic acid salt, which after coupling as the free amine with alpha-amino-alpha-p-nitrobenzyl-N-pnitrobenzyloxycarbonyl-D-adipate and then hydrogenolysis, yielded [6alpha-3H]penicillin N. 6. Triprotected [10-14C]penicillin N and triprotected [6alpha-3H]penicillin N in admixture were hydrogenolysed to give [10-14C,6alpha-3H]penicillin N.

Introduction of 9-fluorenylmethyloxycarbonyl, trichloroethoxycarbonyl, and benzyloxycarbonyl amine protecting groups into O-unprotected hydroxyamino acids using succinimidyl carbonates

1982 ◽  
Vol 60 (8) ◽  
pp. 976-980 ◽  
Author(s):  
Alenka Paquet
Keyword(s):  
Benzyl Ester ◽  
Protecting Groups ◽  
Efficient Conversion ◽  
Hydroxyamino Acids ◽  
High Yields ◽  
Derivatives Of ◽  
Acid Esters ◽  
Efficient Reagent

9-Fluorenylmethyl succinimidyl, pentachlorophenyl, and benzotriazole-1-yl carbonates were prepared and their reactivity with L-serine and L-serine benzyl ester was compared. The most efficient reagent, 9-fluorenylmethyl succinimidyl carbonate, was used for the preparation of 9-fluorenylmethyloxycarbonyl derivatives of other hydroxyamino acids and hydroxyamino acid esters in high yields. The use of trichloroethyl and benzyl succinimidyl carbonates for an efficient conversion of hydroxyamino acids and their esters into the corresponding N-trichloroethoxycarbonyl and benzyloxycarbonyl derivatives is described.

scholarly journals Crystal structure of Boc-(S)-ABOC-(S)-Ala-(S)-ABOC-(S)-Phe-OBn chloroform monosolvate

2015 ◽  
Vol 71 (10) ◽  
pp. 1193-1195
Author(s):  
Emmanuel Wenger ◽  
Laure Moulat ◽  
Baptiste Legrand ◽  
Muriel Amblard ◽  
Monique Calmès ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Amino Acid ◽  
Carboxylic Acid ◽  
Hydrogen Bonds ◽  
Benzyl Ester ◽  
Protecting Groups ◽  
Amino Acid Residues ◽  
Hybrid Peptide ◽  
Proteinogenic Amino Acid ◽  
Solvent Molecules

In the title compound, phenyl (S)-2-[(S)-(1-{2-[(S)-(1-{[(tert-butoxy)carbonyl]amino}bicyclo[2.2.2]octan-2-yl)formamido]propanamido}bicyclo[2.2.2]octan-2-yl)formamido]-3-phenylpropanoate chloroform monosolvate, C42H56N4O7·CHCl3, the α,β-hybrid peptide contains two non-proteinogenic amino acid residues of (S)-1-aminobicyclo[2.2.2]octane-2-carboxylic acid [(S)-ABOC], two amino acid residues of (S)-2-aminopropanoic acid [(S)-Ala] and (S)-2-amino-3-phenylpropanoic acid [(S)-Phe], and protecting groups oftert-butoxycarbonyl (Boc) and benzyl ester (OBn). The tetramer folds into a right-handed mixed 11/9 helix stabilized by intramoleculari,i + 3 andi,i − 1 C=O...H—N hydrogen bonds. In the crystal, the oligomers are linked by N—H...O=C hydrogen bonds into chains along thea-axis direction. The chloroform solvent molecules are intercalated between the folded chainsviaC—H...O=C interactions.

A convenient preparative method for tryptophan benzyl esters

1975 ◽  
Vol 28 (9) ◽  
pp. 2065 ◽  
Author(s):  
K Williams ◽  
B Halpern
Keyword(s):  
Amino Acid ◽  
Catalytic Hydrogenation ◽  
Synthetic Peptide ◽  
Preparative Method ◽  
Benzyl Ester ◽  
Protecting Groups ◽  
Benzyl Esters

The utilization of amino acid benzyl esters in synthetic peptide procedures offers advantages over the corresponding methyl or ethyl derivatives. Whereas the latter groups must by cleaved by alkaline saponification, the benzyl ester function can be removed by acidolysis or by catalytic hydrogenation under conditions which permit the simultaneous cleavage of N-acyl-protecting groups such as t-Boc or CBzl.*

Pd/charcoal-catalysed cleavage of benzyl ester protecting groups in poly(benzyl acrylate) and poly(benzyl methacrylate)

Polymer ◽  
1991 ◽  
Vol 32 (14) ◽  
pp. 2659-2665 ◽  
Author(s):  
A. Caron ◽  
C. Bunel ◽  
C. Braud ◽  
M. Vert
Keyword(s):  
Benzyl Ester ◽  
Protecting Groups
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