Substituent Interactions in Di- and Tri-acyl Derivatives of cis- and trans- 2-Hydrazinocyclopentanol

1973 ◽  
Vol 51 (10) ◽  
pp. 1587-1597 ◽  
Author(s):  
J. A. Campbell ◽  
Donald Mackay
Keyword(s):  
Acetyl Derivative ◽  
Ester Group ◽  
Major Product ◽  
Amide Group ◽  
Acid Mixture ◽  
Tosyl Chloride ◽  
Cis And Trans ◽  
Work Up ◽  
Derivatives Of ◽  
Acyl Derivatives

The action of thionyl chloride followed by an alkaline work-up quantitatively isomerizes trans-1,2-dibenzoyl-1-(2-hydroxylcyclopentyl)hydrazine(5) to cis-2-benzoyl-1-(2-benzoyloxycyclopentyl)hydrazine (3). One equivalent of tosyl chloride in pyridine converts 5 to an intermediate which can be hydrolyzed to a mixture of 3 and 5 or can be transformed to the N-tosyl derivative 13 by tosylation and then hydrolysis. Oxazolidine structures are suggested as intermediates for these reactions.The alcohol 2 can also be isomerized to 3, using 0.8 N aqueous ethanolic hydrochloric acid, to which 5 is inert. The ester 3 is again the major product in the hydrolysis by this acid mixture of the cis-tribenzoyl derivative 17, the cis-N1-p-anisoyl derivative 21a and the cis-N1-acetyl derivative 21b, the amide group being cleaved much more rapidly than the ester, especially in the case of 21b. A mechanism involving ester participation by way of an oxazolidinium cation is proposed for these amide hydrolyses, and this is supported by tracer studies.The trans-esters 24a and b hydrolyze mainly at the ester group with retention of configuration.Polymorphism is a common phenomenon among the title compounds.

The chromous chloride promoted addition of N-haloamides to olefins. V. The addition of N-chloroamides to enol ethers: synthesis of acyloxy and acyl derivatives of α-amino acetals and ketals (aldehydes and ketones) and of 2-amino sugars

1978 ◽  
Vol 56 (1) ◽  
pp. 119-130 ◽  
Author(s):  
Hugues Driguez ◽  
Jean-Paul Vermes ◽  
Jean Lessard
Keyword(s):  
Addition Product ◽  
Amino Sugars ◽  
Enol Ethers ◽  
Aldehydes And Ketones ◽  
Work Up ◽  
Derivatives Of ◽  
Chromous Chloride ◽  
Acyl Derivatives

The chromous chloride promoted addition of N-chlorocarbamates and N-chlorocarboxamides to 1-methoxycyclohexene, ethoxyethylene, dihydropyran, and (1-methoxyethylidene)-cyclohexane gave, in 60 to 85% yields, either α-acyloxy- or α-acylamino ketals and acetals, or the corresponding ketones and aldehydes depending on the work-up conditions. The regio-specificity of the addition was higher with the first two enol ethers (≥97%) than with the latter two (≥85%). N-Chlorourethane was added to 17-methoxymethylenandrost-4-en-3-one (19) and the sole addition product isolated was the 17α-chloro-20-ethoxycarbonylamino derivative 20 in 75% yield. Additions to triacetyl-D-glucal and 3-O-acetyl-4,6-O-benzylidene-D-glucal followed by solvolysis under Koenigs–Knorr conditions led predominantly to 2-amino-gluco-pyranosides in 30 to 65% yields, whereas additions to 3-O-acetyl-4,6-O-benzylidene-D-allal gave 2-amino altropyranosides in 40 to 56% yields.

Isolation of the Products Resulting from the Reaction of cis and trans Diaminedichloroplatinum [II] with DNA and Chromatin on the Dowex 50 W Column

1984 ◽  
Vol 39 (11-12) ◽  
pp. 1057-1062 ◽  
Author(s):  
Ryszard Olinski ◽  
Zofia Walter
Keyword(s):  
Nucleic Acid ◽  
Trans Isomer ◽  
Main Product ◽  
Double Helix ◽  
Major Product ◽  
Nucleic Acid Bases ◽  
Chromosomal Proteins ◽  
Cis And Trans ◽  
Derivatives Of ◽  
Cis Isomer

Abstract The production of platinated derivatives of nucleic acid bases resulting from the reaction of cis and trans DDP with DNA and chrom atin was studied. Bifunctional complex of guanine appeared to be the major product of the interaction of cis isomer with both DNA and chromatin, although other bifunctional adducts of A-Pt-G and A-Pt-A were also isolated. The main product of the interaction of trans DDP with DNA was a monofunctional adduct of guanine. Small amounts of the bifunctional complexes were also isolated. When ssDNA was incubated with trans DDP more bifunctional complexes appeared, what suggests that geometric constrains of double helix prevent formation of these complexes. Trans isomer reacts more easily with chromosomal proteins than cis DDP does. Therefore after the reaction of trans DDP with chromatin less platination occurs on DNA moieties.

Kinetics and mechanism of rearrangement and methanolysis of acylphenylthioureas

1985 ◽  
Vol 50 (3) ◽  
pp. 766-778 ◽  
Author(s):  
Jaromír Kaválek ◽  
Josef Jirman ◽  
Vojeslav Štěrba
Keyword(s):  
Acetyl Derivative ◽  
Base Catalysis ◽  
Methyl Group ◽  
Phenyl Derivative ◽  
Benzoyl Group ◽  
Order Of Magnitude ◽  
Acetyl Group ◽  
Methyl Derivatives ◽  
Derivatives Of ◽  
Acyl Derivatives

S-Acyl-1-phenylthioureas and their 3-methyl derivatives are rearranged to 1-acyl derivatives of thiourea in methanolic solution. The rearrangement of the 1-acyl-1-phenyl derivative to the thermodynamically more stable 3-acyl derivative is subject to specific base catalysis. The rearrangement of acetyl group is about 2 orders of magnitude slower than that of benzoyl group. 1-Acetyl-l-phenylthiourea undergoes base-catalyzed methanolysis (giving phenylthiourea and methyl acetate) instead of the rearrangement. The methanolysis rates of l-acyl-3-phenylthioureas and their N-methyl derivatives have been measured. The acetylthioureas react at most 3x faster than the benzoyl derivatives. The methyl group at the nitrogen adjacent to acyl group accelerates the solvolysis by almost 2 orders of magnitude; the methyl group at the other nitrogen atom retards the solvolysis by almost 1 order of magnitude. Replacement of hydrogen atom by methyl group at the phenyl-substituted nitrogen increases acidity of the phenylacetylthiourea by 2 orders of magnitude. The same replacement at the benzoyl-substituted nitrogen increases the acidity by 3 orders of magnitude, the increase in the case of the acetyl derivative being as large as 4 orders of magnitude.

The role of secondary alcoholic groups of D-galacturonan in its degradation with exo-D-galacturonanase

1980 ◽  
Vol 45 (2) ◽  
pp. 427-434 ◽  
Author(s):  
Kveta Heinrichová ◽  
Rudolf Kohn
Keyword(s):  
Acetyl Derivative ◽  
Competitive Inhibitor ◽  
Hydroxyl Groups ◽  
Pectic Acid ◽  
Substrate Complex ◽  
Enzyme Substrate ◽  
The Individual ◽  
Degradation Degree ◽  
Derivatives Of

The effect of exo-D-galacturonanase from carrot on O-acetyl derivatives of pectic acid of variousacetylation degree was studied. Substitution of hydroxyl groups at C(2) and C(3) of D-galactopyranuronic acid units influences the initial rate of degradation, degree of degradation and its maximum rate, the differences being found also in the time of limit degradations of the individual O-acetyl derivatives. Value of the apparent Michaelis constant increases with increase of substitution and value of Vmax changes. O-Acetyl derivatives act as a competitive inhibitor of degradation of D-galacturonan. The extent of the inhibition effect depends on the degree of substitution. The only product of enzymic reaction is D-galactopyranuronic acid, what indicates that no degradation of the terminal substituted unit of O-acetyl derivative of pectic acid takes place. Substitution of hydroxyl groups influences the affinity of the enzyme towards the modified substrate. The results let us presume that hydroxyl groups at C(2) and C(3) of galacturonic unit of pectic acid are essential for formation of the enzyme-substrate complex.

scholarly journals Synthesis, Antiproliferative Activity and Radical Scavenging Ability of 5-O-Acyl Derivatives of Quercetin

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1608
Author(s):  
Stephen Lo ◽  
Euphemia Leung ◽  
Bruno Fedrizzi ◽  
David Barker
Keyword(s):  
Antiproliferative Activity ◽  
Biological Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Breast Cancer Cell Lines ◽  
Scavenging Activity ◽  
Plant Materials ◽  
Wide Range ◽  
Derivatives Of ◽  
Acyl Derivatives

Quercetin is a flavonoid that is found in many plant materials, including commonly eaten fruits and vegetables. The compound is well known for its wide range of biological activities. In this study, 5-O-acyl derivatives of quercetin were synthesised and assessed for their antiproliferative activity against the HCT116 colon cancer and MDA-MB-231 breast cancer cell lines; and their radical scavenging activity against the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical species. Four derivatives were found to have improved the antiproliferative activity compared to quercetin whilst retaining radical scavenging activity.

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