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.

scholarly journals A New Generation of Glycoconjugated Azo Dyes Based on Aminosugars

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Lorenzo Guazzelli ◽  
Giorgio Catelani ◽  
Felicia D’Andrea
Keyword(s):  
Acid Hydrolysis ◽  
Azo Dyes ◽  
Azo Dye ◽  
Protecting Groups ◽  
Third Generation ◽  
Sugar Moiety ◽  
The Third ◽  
New Generation ◽  
Monoazo Dyes ◽  
Hydrolysis Of

The third generation of glycoconjugated azo dyes (GADs) was prepared linking monoazo dyes to 6-amino-6-deoxy-d-galactose or 6′amino-6′-deoxylactose through mixed amido-ester connections. The complementary conjugation reactions were studied using the succinyl derivative of either the acetal protected aminosugar or the azo dye. Target “naturalized” GADs were obtained after acid hydrolysis of the acetal protecting groups present on the sugar moiety.

Trialkylsilanes as scavengers for the trifluoroacetic acid deblocking of protecting groups in peptide synthesis

1989 ◽  
Vol 30 (21) ◽  
pp. 2739-2742 ◽  
Author(s):  
Daniel A. Pearson ◽  
Mary Blanchette ◽  
Mary Lou Baker ◽  
Cathy A. Guindon
Keyword(s):  
Peptide Synthesis ◽  
Trifluoroacetic Acid ◽  
Protecting Groups

Partial hydrolysis of acyl 1,6-anhydro-β-D-glucopyranose

1984 ◽  
Vol 49 (8) ◽  
pp. 1780-1787 ◽  
Author(s):  
Štefan Kučár ◽  
Juraj Zámocký ◽  
Juraj Zemek ◽  
Dušan Anderle ◽  
Mária Matulová
Keyword(s):  
Acid Hydrolysis ◽  
Hydrazine Hydrate ◽  
Hydrogen Chloride ◽  
Ester Group ◽  
The Other ◽  
Hydroxyl Group ◽  
Partial Hydrolysis ◽  
Substantial Influence ◽  
Hydrolysis Of ◽  
Derivatives Of

Partial hydrolysis of per-O-acetyl- and per-O-benzoyl derivatives of 1,6-anhydro-β-D-glucopyranose with methanolic hydrogen chloride and hydrazine hydrate was investigated. The acyl group at C(3) is of substantial influence on the course of hydrolysis. The esterified hydroxyl group at C(3) was found to be most stable on acid hydrolysis with methanolic hydrogen chloride when compared with that at C(2), or C(4); on the other hand, this ester group is the most labile upon hydrolysis with hydrazine hydrate. Selectivity of the respective ester groups towards hydrolysis made it possible to prepare all variations of acetyl and benzoyl derivatives of 1,6-anhydro-β-D-glucopyranose.

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.

Measurement of β-Glucan in Mushrooms and Mycelial Products

2016 ◽  
Vol 99 (2) ◽  
pp. 364-373 ◽  
Author(s):  
Barry V McCleary ◽  
Anna Draga
Keyword(s):  
Enzymatic Hydrolysis ◽  
Glucose Oxidase ◽  
Acid Hydrolysis ◽  
Trifluoroacetic Acid ◽  
Ganoderma Lucidum ◽  
Reliable Method ◽  
The Other ◽  
Free Glucose ◽  
The Difference ◽  
Hydrolysis Of

Abstract A robust and reliable method has been developed for the measurement of β-glucan in mushroom and mycelial products. Total glucan (plus free glucose and glucose from sucrose) was measured using controlled acid hydrolysis with H2SO4 and the glucose released specifically was measured using glucose oxidase/peroxidase reagent. α-Glucan (starch/glycogen) plus free glucose and glucose from sucrose were specifically measured after hydrolysis of starch/glycogen to glucose with glucoamylase and sucrose to glucose plus fructose with invertase and the glucose specifically measured with GOPOD reagent. β-Glucan was determined by the difference. Several acid and enzyme-based methods for the hydrolysis of the β-glucan were compared, and the best option was the method using H2SO4. For most samples, similar β-glucan values were obtained with both the optimized HCl and H2SO4 procedures. However, in the case of certain samples, specifically Ganoderma lucidum and Poria cocus, the H2SO4 procedure resulted in significantly higher values. Hydrolysis with 2 N trifluoroacetic acid at 120°C was found to be much less effective than either of the other two acids evaluated. Assays based totally on enzymatic hydrolysis, in general, yielded much lower values than those obtained with the H2SO4 procedure.

Anhydro Sugar Formation in Acid and Base Hydrolyses of 3,4-Di-O-methylsulfonyl-D-mannitol: a Rapid Route to 1,4:3,6-Dianhydro-D-iditol(D-Isoidide)

1974 ◽  
Vol 52 (19) ◽  
pp. 3367-3372 ◽  
Author(s):  
David Roy Hicks ◽  
Bert Fraser-Reid
Keyword(s):  
Acid Hydrolysis ◽  
Ester Group ◽  
Sulfonate Group ◽  
Acid And Base ◽  
Hydrolysis Of

Brief acid hydrolysis of 1,2:5,6-di-O-isopropylidene-3,4-di-O-methylsulfonyl-D-mannitol (1a), removes the isopropylidene groups giving the disulfonated hexitol, 2a. Upon continued acid hydrolysis of 2a, one sulfonate group is lost with formation of a sulfonated monoanhydro hexitol, 5a, then the second ester group is lost to give 1,4:3,6-dianhydro-D-iditol (D-isoidide, 3a). If the disulfonate, 2a, is treated with base, an isomeric dianhydro hexitol, the bisoxirane 4, is formed. Under similar basic conditions, the monoanhydro hexitol, 5a, is stable. On acid hydrolysis, the bisoxirane, 4, gives hexitols and only 20% of D-isoidide, which indicates that 4 cannot be an intermediate in the conversion of 2a to 3a. These results indicate that, in 2a at least, five-membered anhydro rings are formed preferentially in acid hydrolyses and three-membered rings in saponification.The stage and course of hydrolysis of 2a are readily monitored by observing the τ 4–6 region in the n.m.r. spectra of D2O samples of the hydrolysate.

A Rapid Vapor-Phase Acid (Hydrochloric Acid and Trifluoroacetic Acid) Hydrolysis of Peptide and Protein

1987 ◽  
Vol 102 (6) ◽  
pp. 1593-1597 ◽  
Author(s):  
Akira TSUGITA ◽  
Toyoaki UCHIDA ◽  
H.Werner MEWES ◽  
Tatsuaki ATAKA
Keyword(s):  
Hydrochloric Acid ◽  
Acid Hydrolysis ◽  
Vapor Phase ◽  
Trifluoroacetic Acid ◽  
Hydrolysis Of

Preparation of enantiomeric and racemic 2,3,4,5-tetrahydroxypentyl derivatives of adenine, cytosine and uracil

1982 ◽  
Vol 47 (10) ◽  
pp. 2786-2805 ◽  
Author(s):  
Antonín Holý
Keyword(s):  
Acid Hydrolysis ◽  
Sodium Borohydride ◽  
Catalytic Hydrogenation ◽  
Protecting Groups ◽  
Sodium Salts ◽  
Hydrolysis Of ◽  
Derivatives Of ◽  
Subsequent Acid

1-(Adenin-9-yl)-1-deoxy-DL-ribitol (III), -D-arabitol (IXa), -L-arabitol (XIVa), -DL-xylitol (XXIVa), 1-(cytosin-L-yl)-1-deoxy-D-arabitol (IXb), -L-arabitol (XIVb), 1-(uracil-1-yl)-1-deoxy-D-arabitol (IXc), -L-arabitol (XIVc) and -DL-xylitol (XXIVb) were prepared by reaction of 1-O-p-toluenesulfonyl-2,3:4,5-di-O-isopropylidenealditols Ib, VIIb, XIIb and XXIIb with sodium salts of adenine, N4-benzoylcytosine or 4-methoxy-2-pyrimidone followed by removal of the protecting groups. Condensation of the mentioned sodium salts with methyl 5-O-p-toluenesulfonyl-2,3-O-isopropylidene-β-D-ribofuranoside (IV) with subsequent acid hydrolysis and reduction with sodium borohydride afforded 1-(adenin-9-yl)-1-deoxy-L-ribitol (VIa) and 1-(cytosin-1-yl)-1-deoxy-L-ribitol (VIb). 1-(Adenin-9-yl)-1-deoxy-L-lyxitol (XVII), -L-lyxitol (XVIII) and -2-O-methyl-D-lyxitol (XXI) were prepared analogously. Acid hydrolysis of 5-(adenin-9-yl)-5-deoxy-4-O-benzyl-1,2-O-isopropylidene-α-D-xylofuranose (XXVa), followed by reduction with sodium borohydride and catalytic hydrogenation, gave 1-(adenin-9-yl)-1-deoxy-L-xylitol (XXVIb).

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