Cyclic hydroxycarboxylic acids. I. Synthesis, stereochemistry and reactivity of 2,3-trans-2,3-Dihydroxycyclopentanecarboxylic acids

1976 ◽  
Vol 29 (7) ◽  
pp. 1493 ◽  
Author(s):  
RP Philp ◽  
AV Robertson
Keyword(s):  
Proton Magnetic Resonance ◽  
Methyl Esters ◽  
Performic Acid ◽  
Hydroxy Acids ◽  
Dihydroxy Acid ◽  
Tosyl Chloride ◽  
Hydroxycarboxylic Acids ◽  
Derivatives Of ◽  
Acidic Methanolysis ◽  
Infrared Data

Cyclopent-2-enecarboxylic acid and performic acid give a mixture of approximately equal amounts of the corresponding c-2,t-3- and t-2,c-3-dihydroxycyclopentane-r-1-carboxylic acids. The mixture was separated by chromatography of the methyl esters. Relative configurations were assigned from the action of tosyl chloride-pyridine on the separate acids. The c-2,t-3-dihydroxy acid yields a t-3-tosyloxy ,β-lactone and the t-2,c-3-dihydroxy acid yields a r-2-tosyloxy γ-lactone. Structures of the lactones were proved by correlating the products of acidic methanolysis and of alkaline hydrolysis with various derivatives of the acids. Proton magnetic resonance spectra are reported for 21 compounds from the two stereochemical families, including acetate, trifluoroacetate, tosylate and mesylate derivatives. Infrared data for relded lactones are tabulated. Formation of β-lactones from β-hydroxy acids by tosyl chloride appears to be unprecedented.

Cyclic hydroxycarboxylic acids. III. Tosylation studies on Mono- and Di-hydroxycyclopentanecarboxylates and Mono- and Di-hydroxyprolines

1977 ◽  
Vol 30 (1) ◽  
pp. 131 ◽  
Author(s):  
RP Philp ◽  
AV Robertson
Keyword(s):  
Free Amino ◽  
Heterogeneous System ◽  
Methyl Esters ◽  
Hydroxyl Groups ◽  
Large Excess ◽  
Molar Ratios ◽  
Tosyl Chloride ◽  
Hydroxycarboxylic Acids ◽  
Hydroxy Proline ◽  
Cis And Trans

A large excess of reagent is needed for satisfactory ditosylation of methyl c-2,t-3- and t-2,c-3-di-hydroxycyclopentane-r-1-carboxylates using tosyl chloride-pyridine at 5° overnight. With less reagent, mixtures are produced from which one monotosyl derivative of the t-2,c- 3-series was isolated and its structure proved. By contrast, the methyl cis- and trans-2-hydroxycyclopentanecarboxylates readily tosylate with normal molar ratios of reagent. In the proline series ditosylation of 2,3-trans- 3,4-cis-3,4-dihydroxy-N-tosylproline methyl ester occurs normally in tosyl chloride-pyridine, and so does tosylation of both cis- and trans-4-hydroxy-N-tosylproline methyl esters. On the other hand tosylation of the 3-hydroxy counterparts is very slow, although acetylation of these 3-hydroxyl groups proceeds normally. The O-tosylation results are striking for the lack of pattern. A comparison is also made of O-tosylation accompanying N-tosylation of the free amino acids cis- and trans-3-hydroxy-proline, cis- and trans- 4- hydroxyproline, and the two cis-glycols of 3,4-dihydroxyproline in the heterogeneous system tosyl chloride-ether-aqueous NaOH. Significant O- tosylation occurs in some cases but not in others. This correlation permits assignment of structure to a mono-O-tosyl derivative of a 3,4- dihydroxy-N-tosylproline obtained previously by us.

scholarly journals Novel Amino Acid Derivatives of Quinolines as Potential Antibacterial and Fluorophore Agents

2020 ◽  
Vol 88 (4) ◽  
pp. 57
Author(s):  
Oussama Moussaoui ◽  
Rajendra Bhadane ◽  
Riham Sghyar ◽  
El Mestafa El Hadrami ◽  
Soukaina El Amrani ◽  
...  
Keyword(s):  
Amino Acid ◽  
Methyl Esters ◽  
Amino Acid Derivatives ◽  
Bacterial Strains ◽  
Fluorescent Properties ◽  
Topoisomerase Iv ◽  
Microdilution Method ◽  
Hydrolysis Of ◽  
Derivatives Of

A new series of amino acid derivatives of quinolines was synthesized through the hydrolysis of amino acid methyl esters of quinoline carboxamides with alkali hydroxide. The compounds were purified on silica gel by column chromatography and further characterized by TLC, NMR and ESI-TOF mass spectrometry. All compounds were screened for in vitro antimicrobial activity against different bacterial strains using the microdilution method. Most of the synthesized amino acid-quinolines show more potent or equipotent inhibitory action against the tested bacteria than their correspond esters. In addition, many of them exhibit fluorescent properties and could possibly be utilized as fluorophores. Molecular docking and simulation studies of the compounds at putative bacterial target enzymes suggest that the antimicrobial potency of these synthesized analogues could be due to enzyme inhibition via their favorable binding at the fluoroquinolone binding site at the GyrA subunit of DNA gyrase and/or the ParC subunit of topoisomerase-IV.

scholarly journals SYNTHESIS AND ANTIMICROBIAL EVALUATION OF QUINAZOLINONE PEPTIDE DERIVATIVES

2017 ◽  
Vol 10 (16) ◽  
pp. 7 ◽  
Author(s):  
Bhupinder Kapoor ◽  
Arshid Nabi ◽  
Reena Gupta ◽  
Mukta Gupta
Keyword(s):  
Antibacterial Activity ◽  
Amino Acid ◽  
Antimicrobial Agents ◽  
Methyl Esters ◽  
Standard Drug ◽  
Amino Acid Peptide ◽  
Chemical Structures ◽  
1H Nuclear Magnetic Resonance ◽  
Peptide Derivatives ◽  
Derivatives Of

  Objective: The increased microbial resistance against commercially available drugs initiated the development of novel and safe antimicrobial agents in last few decades. In this view, a series of amino acid/dipeptide derivatives of quinazolin-3(4H)-one was synthesized and was evaluated for their antimicrobial potential.Method: Synthesis of amino acid/peptide derivatives were carried out by coupling 5-(2-(2-chlorophenyl)-4-oxoquinazolin-3(4H)-yl)-2-hydroxy benzoic acid with amino acid/dipeptide methyl esters in the presence of dicyclohexylcarbodiimide and N-methylmorpholine. The chemical structures of synthesized compounds were characterized by 1H nuclear magnetic resonance and infrared spectroscopy and were screened for antibacterial activity by disc diffusion method.Results: All the synthesized derivatives exhibited moderate to significant antibacterial activity against both Gram-positive and Gram-negative bacteria. The potency of compound 5d was comparable to standard drug ciprofloxacin in all the strains of bacteria used. The compound 5a was found to be more active against Streptococcus pyogenes and Staphylococcus aureus while compound 5c against Pseudomonas aeruginosa and Escherichia coli. Conclusion: Peptide derivatives of quinazolinone are promising antimicrobial agent and can be used for the synthesis of other novel compounds.

scholarly journals Synthesis of monoketo and monohydroxy eicosanoic acids and esters with substituents at odd-numbered (3-13) carbons

2002 ◽  
Vol 67 (7) ◽  
pp. 473-480 ◽  
Author(s):  
Hulya Çelik
Keyword(s):  
Nmr Spectroscopy ◽  
High Purity ◽  
1H Nmr Spectroscopy ◽  
Methyl Esters ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Keto Acids ◽  
Physical And Chemical ◽  
Derivatives Of ◽  
And Chemical Properties

In this study, monoketo and monohydroxy eicosanoic acids and their methyl esters with the position of the substituent on odd numbered carbon atoms from 3 to 13 were synthesized with high purity. Furthermore, the semicarbazone and anilide derivatives of the obtained keto acids were prepared. They were characterized by TLC, IR and 1H-NMR spectroscopy and their physical and chemical properties were established.

scholarly journals Unusual Regularity in GC Retention of Simple Amino Acid Derivatives

2019 ◽  
Vol 6 (1) ◽  
pp. 3-14 ◽  
Author(s):  
Igor G. Zenkevich ◽  
Nino G. Todua ◽  
Anzor I. Mikaia
Keyword(s):  
Gas Chromatography ◽  
Retention Index ◽  
Methyl Esters ◽  
Elution Order ◽  
Alkyl Esters ◽  
Methyl Group ◽  
The Difference ◽  
Direct Use ◽  
Derivatives Of

Background: Application of simple regularities and general principles along with direct use of reference gas chromatography retention index data for reliable structure determination of compounds can be enhanced by determination of new regularities that are specific to certain structural elements. Objective: Revelation and interpretation of an anomaly in the elution order of alkyl esters of alkoxycarbonyl derivatives of glycine and alanine on standard and semi-standard non-polar phases. Method: Preliminary derivatization of amino acids to alkyl esters of N-alkoxycarbonyl analogs and interpretation of their gas chromatographic characteristics. Results: Alkyl esters of N-alkoxycarbonyl derivatives of alanine (Alkyl = C2H5, n- and iso-C3H7) elute prior to the same derivatives of glycine, despite the presence of an additional methyl group at C(2) in the molecule. Elution order is reversed for methyl esters of N-methoxycarbonyl derivatives. Conclusion: It is established that the peculiar behavior of alkyl esters of N-alkoxycarbonyl derivatives of glycine and alanine agrees with the concepts of gas chromatography and the known retention index regularities of organic compounds. A decrease of retention index values is a result of an introduction of an additional methyl group to a carbon atom connected to two polar fragments in a molecule like CH2XY. The dependence of the difference of retention index values for homologs of the types of CH3-CHXY and CH2XY vs. the total mass of fragments (X + Y) is similar to those for other sub-groups of analytes.

The conformational preference and barrier to internal rotation of an equatorial 3,5-dichlorophenyl group by the J method. Derivatives of cyclohexane, 1,3-dithiane, 1,3-dioxane, and 1,3-dioxolane

1979 ◽  
Vol 57 (3) ◽  
pp. 355-359 ◽  
Author(s):  
Ted Schaefer ◽  
Walter Niemczura ◽  
Werner Danchura
Keyword(s):  
Magnetic Resonance ◽  
Molecular Mechanics ◽  
Internal Rotation ◽  
Phenyl Ring ◽  
Proton Magnetic Resonance ◽  
Conformational Preference ◽  
Molecular Mechanics Calculations ◽  
X Ray ◽  
Carbon Carbon Bond ◽  
Derivatives Of

We report the preparation and the analysis of the phenyl ring proton magnetic resonance spectra of 3,5-dichlorophenylcyclohexane and of the 2-(3,5-dichlorophenyl) derivatives of 1,3-dioxane, 1,3-dithiane, and 1,3-dioxolane. With the exception of the dioxolanes these compounds exist predominantly as the equatorial isomers. The J method is used to show that the phenyl moiety prefers the conformation in which the α C—H bond lies in the phenyl plane. The predominantly twofold barriers to rotation about the carbon–carbon bond between the two ring systems are 2.0 ± 0.3, 0.4 ± 0.2, 2.2 ± 0.3, 0.85 ± 0.3 kcal/mol for these compounds, in the order given above. The low value for the barrier in the 1,3-dioxane derivative agrees reasonably well with molecular mechanics calculations and with the results of calorimetric and X-ray studies on equatorial 2-phenyl-1,3-dioxane.

ChemInform Abstract: PROTON MAGNETIC RESONANCE SPECTRA OF ANIONIC Σ-COMPLEXES OF TRINITROBENZENE WITH CYCLOPENTADIENYL AND INDENYL DERIVATIVES OF TIN

1976 ◽  
Vol 7 (50) ◽  
pp. no-no
Author(s):  
YU. A. USTYNYUK ◽  
G. A. ARTAMKINA ◽  
YU. N. LUZIKOV ◽  
YU. K. GRISHIN ◽  
A. A. AZIZOV ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Derivatives Of ◽  
Magnetic Resonance Spectra

Cycloaddition d'ylures d'azométhine dérivés de la 3,4-dihydro-6,7-diméthoxy-3-méthoxycarbonyl-isoquinoléine

1991 ◽  
Vol 69 (7) ◽  
pp. 1156-1160 ◽  
Author(s):  
Tahar Lakhlifi ◽  
Ahmed Sedqui ◽  
Bernard Laude ◽  
Nguyen Dinh An ◽  
Joël Vebrel
Keyword(s):  
Magnetic Resonance ◽  
Key Words ◽  
Proton Magnetic Resonance ◽  
Azomethine Ylide ◽  
Magnetic Resonance Data ◽  
Resonance Data ◽  
Azabicyclic Compounds ◽  
Derivatives Of ◽  
Proton Magnetic Resonance Data

Three azomethine ylide precursors including the methyl 3,4-dihydro-6,7-dimethoxyisoquinoline-3carboxylate moiety were synthesized. The 1,3-dipolar species formed from these products react with activated dipolarophilic olefines leading diastereospecifically to derivatives of 4′,5′-dimethoxy-1,2-benzo-4,7-imino-4-methoxycarbonyl-1-cycloheptene. Proton magnetic resonance data allowed the determination of the stereochemistry of the cycloadducts. Key words: cyclic azomethine ylide, azabicyclic compounds, stereochemistry.

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