P-Methoxybenzyl esters of amino acids-their preparation and use in peptide synthesis

1971 ◽  
Vol 24 (8) ◽  
pp. 1695 ◽  
Author(s):  
BJ Maclaren
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Peptide Synthesis ◽  
Trifluoroacetic Acid ◽  
Ester Group

Various N-protected amino acids have been alkylated with p- methoxybenzyl chloride to give the corresponding esters. These were then converted into amino acid p-methoxybenzyl esters by selective acidolysis of the N-o-nitrophenylsulphenyl and N-trityl derivatives, or in poor yield by hydrazinolysis of the N-phthaloyl derivative. S- Benzylcysteine p-methoxybenzyl ester is obtained without racemiza- tion. These esters have been applied to the syntheses of several dipeptides, the ester group being cleaved by cold trifluoroacetic acid.

Selective acid hydrolysis of 2,4,6-trimethylbenzyl esters and its application in peptide synthesis

1966 ◽  
Vol 19 (8) ◽  
pp. 1511 ◽  
Author(s):  
FHC Stewart
Keyword(s):  
Acid Hydrolysis ◽  
Peptide Synthesis ◽  
Trifluoroacetic Acid ◽  
Ester Group ◽  
Protecting Groups ◽  
Alkaline Conditions ◽  
Hydrolysis Of

Experiments with various N-acylamino acid 2,4,6-trimethylbenzyl esters have shown that the ester group is cleaved selectively by cold trifluoroacetic acid without affecting benzyloxycarbonyl, formyl, or phthaloyl amino-protecting groups present. The possible value of this selective behaviour in peptide syntheses where the use of alkaline conditions would be detrimental is illustrated by the synthesis of certain dipeptide derivatives.

Fmoc amino acid fluorides in peptide synthesis — Extension of the method to extremely hindered amino acids

1996 ◽  
Vol 37 (31) ◽  
pp. 5483-5486 ◽  
Author(s):  
Holger Wenschuh ◽  
Michael Beyermann ◽  
Rüdiger Winter ◽  
Michael Bienert ◽  
Dumitru Ionescu ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Peptide Synthesis ◽  
Amino Acid Fluorides ◽  
Acid Fluorides

N-Methylamino acids in peptide synthesis. V. The synthesis of N-tert-butyloxycarbonyl, N-methylamino acids by N-methylation

1977 ◽  
Vol 55 (5) ◽  
pp. 906-910 ◽  
Author(s):  
S. T. Cheung ◽  
N. Leo Benoiton
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Methyl Iodide ◽  
Peptide Synthesis ◽  
Room Temperature ◽  
Sodium Hydride ◽  
Amino Acid Derivatives ◽  
Enantiomerically Pure ◽  
Neutral Amino Acids ◽  
Related Data

The preparation of enantiomerically pure N-tert-butyloxycarbonyl,N-methylamino acids by N-methylation of the parent amino acid derivatives using sodium hydride and methyl iodide in tetrahydrofuran at room temperature is described for neutral amino acids including O-benzyl-protected threonine and tyrosine. Methylation of the O-benzylserine derivative under these conditions gives the N-methyldehydroalanine derivative. The β-elimination is completely suppressed, giving the corresponding N-methylserine derivative when the reaction is carried out at 5 °C. Other related data on N-methylation and N-methylamino acid derivatives are presented.

An Efficient Method for Constructing Cyclic β-Amino Acids Bearing Quaternary Stereocenters

Synlett ◽  
2019 ◽  
Vol 30 (05) ◽  
pp. 593-599 ◽  
Author(s):  
Shende Jiang ◽  
Guang Yang ◽  
Shuanglin Qin ◽  
Tongtong Liu ◽  
Yunhao Luo ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Efficient Method ◽  
Ester Group ◽  
Chiral Auxiliary ◽  
Allyl Ester ◽  
Stereogenic Centers ◽  
Quaternary Stereocenters ◽  
High Yields ◽  
Quaternary Stereogenic Centers

This paper describes an efficient method for constructing cyclic β-amino acids bearing quaternary stereocenters. NaHMDS-promoted asymmetric α-alkylation was employed to obtain the key intermediates with quaternary stereogenic centers, which were subsequently reduced by NaBH4 in 10% methanol in THF, with high yields and high diastereoselectivities. By removing the allyl ester group and the chiral auxiliary, the corresponding cyclic β-amino acid hydrochlorides were finally obtained.

scholarly journals Substrate specificity of l-δ-(α-aminoadipoyl)-l-cysteinyl-d-valine synthetase from Cephalosporium acremonium: demonstration of the structure of several unnatural tripeptide products

1994 ◽  
Vol 301 (2) ◽  
pp. 367-372 ◽  
Author(s):  
J E Baldwin ◽  
C Y Shiau ◽  
M F Byford ◽  
C J Schofield
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Substrate Specificity ◽  
Electrospray Ionization ◽  
Peptide Synthesis ◽  
Thiol Group ◽  
Cephalosporium Acremonium ◽  
Peptide Synthetases ◽  
Peptide Formation ◽  
Combined Use

Potential substrates for L-delta-(alpha-aminoadipoyl)-L-(cysteinyl)-D-valine (ACV) synthetase were initially identified using both the amino-acid-dependent ATP<-->pyrophosphate exchange reaction catalysed by the enzyme and the incorporation of 14C-radiolabelled cysteine and valine into potential peptide products. S-Carboxymethylcysteine was an effective substitute for alpha-aminoadipate and both allylglycine and vinylglycine could substitute for cysteine, indicating that the thiol group of cysteine is not essential for peptide formation. L-allo-Isoleucine but not L-isoleucine substituted effectively for valine. The structures of the presumed peptide products derived from these amino acids were confirmed by combined use of electrospray-ionization m.s. (e.s.m.s.) and 1H n.m.r. These results clearly indicate that, in common with other peptide synthetases, but in contrast with ribosomal peptide synthesis, ACV synthetase has a relatively broad substrate specificity.

scholarly journals One-Pot Ring-Opening Peptide Synthesis Using α,α-Difluoro-β-Lactams

Synthesis ◽  
2020 ◽  
Vol 52 (23) ◽  
pp. 3657-3666 ◽  
Author(s):  
Masaaki Omote ◽  
Atsushi Tarui ◽  
Masakazu Ueo ◽  
Marino Morikawa ◽  
Masahiko Tsuta ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Methyl Ester ◽  
Peptide Synthesis ◽  
Ring Opening ◽  
Reactive Intermediates ◽  
One Pot ◽  
Open Chain ◽  
Lactam Ring

α,α-Difluoro-β-lactams successfully underwent ring-opening aminolysis with various amino acids in 2,2,2-trifluoroethanol to afford fluorine-containing peptides. In this aminolysis, it was found that 2,2,2-trifluoroethanol first attacked the α,α-difluoro-β-lactams with cleavage of lactam ring to form the corresponding open-chain 2,2,2-trifluoroethyl esters as reactive intermediates. The trifluoroethyl esters were more electrophilic compared with the corresponding methyl ester and thereby accelerated the aminolysis with various amino acids to form β-amino acid peptides with α,α-difluoromethylene unit.

Pentamethylbenzyl esters of α-hydroxy acids and their use in depsipeptide synthesis

1968 ◽  
Vol 21 (5) ◽  
pp. 1327 ◽  
Author(s):  
FHC Stewart
Keyword(s):  
Amino Acids ◽  
Trifluoroacetic Acid ◽  
Hydroxy Acid ◽  
Ester Group ◽  
Protecting Group ◽  
Hydroxy Acids ◽  
Acidic Conditions ◽  
Crystalline Nature

Pentamethylbenzyl esters of several a-hydroxy acids have been prepared as possible intermediates in depsipeptide synthesis. Potentially useful features of pentamethylbenzyl as a carboxyl-protecting group are the crystalline nature of the esters, and the rapid cleavage of the group under mild acidic conditions. The glycollate, lactate, and mandelate were coupled with various protected amino acids to form crystalline aminoacyl hydroxy acid derivatives. Selective cleavage of the ester group in these compounds was readily effected with cold trifluoroacetic acid, and the products were used in the synthesis of some representative protected depsipeptides.

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