Permanganate oxidation of a methyl group to carboxylic acid

10.1039/sp455 ◽  
2010 ◽  
Author(s):  
Christopher Cooksey
Keyword(s):  
Carboxylic Acid ◽  
Methyl Group ◽  
Permanganate Oxidation

scholarly journals The oxygenation of [3-methyl-3H]desacetoxycephalosporin C [7β-(5-d-aminadipamido)-3-methylceph-3-em-4-carboxylic acid] to [3-hydroxymethyl-3H]desacetylcephalosporin C by 2-oxoglutarate-linked dioxygenases from Acremonium chrysogenum and Streptomyces clavuligerus

1978 ◽  
Vol 173 (3) ◽  
pp. 839-850 ◽  
Author(s):  
M K Turner ◽  
J E Farthing ◽  
S J Brewer
Keyword(s):  
Carboxylic Acid ◽  
Deae Cellulose ◽  
Streptomyces Clavuligerus ◽  
Reducing Agents ◽  
Side Chain ◽  
Acremonium Chrysogenum ◽  
Hydroxymethyl Group ◽  
Methyl Group ◽  
Full Activity

Cell-free extracts of Acremonium chrysogenum and Streptomyces clavuligerus oxidize the 3-methyl group of desacetoxycephalosporin C to a 3-hydroxymethyl group. The enzyme responsible for this reaction in these organisms was purified 20- and 30-fold respectively by chromatography on DEAE-cellulose. The enzymes, which were assayed with [3-methyl-3H]desacetoxycephalosporin C as substrate, have the properties expected of 2-oxoglutarate-linked dioxygenases. They require 2-oxoglutarate, Fe2+ cations and a mixture of reducing agents (dithiothreitol and ascorbate) for full activity. The enzyme from A. chrysogenum, but not that S. clavuligerus, is activated about 10-fold when it is preincubated with a reaction mixture from which either desacetoxycephalosporin C or 2-oxoglutarate is omitted. Fe2+ cations seem to play a key role in this activation. Both enzymes seem highly specific for cephalosporins with the natural 7beta-(5-D-aminoadipamido) side chain and are likely to be responsible for the oxidation of the 3-methylcephem nucleus in vivo.

scholarly journals Caffeine–N-phthaloyl-β-alanine (1/1)

2012 ◽  
Vol 68 (6) ◽  
pp. o1888-o1888 ◽  
Author(s):  
Moazzam H. Bhatti ◽  
Uzma Yunus ◽  
Syed Raza Shah ◽  
Ulrich Flörke
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Carboxylic Acid ◽  
Cooh Group ◽  
Propanoic Acid ◽  
Methyl Group

The title co-crystal [systematic name: 3-(1,3-dioxoisoindolin-2-yl)propanoic acid–1,3,7-trimethyl-1H-purine-2,6(3H,7H)-dione (1/1)], C8H10N4O2·C11H9NO4, is the combination of 1:1 adduct of N-phthaloyl-β-alanine with caffeine. The phthalimide and purine rings in the N-phthaloyl-β-alanine and caffeine molecules are essentially planar, with r.m.s. deviations of the fitted atoms of 0.0078 and 0.0118 Å, respectively. In the crystal, the two molecules are linked via an O—H...N hydrogen bond involving the intact carboxylic acid (COOH) group. The crystal structure is consolidated by C—H...O interactions. The H atoms of a methyl group of the caffeine molecule are disordered over two sets of sites of equal occupancy.

Oxidations with lead tetraacetate. IV. Oxidations of 1,3-benzodithioles

1983 ◽  
Vol 36 (12) ◽  
pp. 2499 ◽  
Author(s):  
C Aromdee ◽  
ER Cole ◽  
G Crank
Keyword(s):  
Carboxylic Acid ◽  
Lead Tetraacetate ◽  
Oxidation Products ◽  
Ring Cleavage ◽  
Methyl Group

Oxidations of 2,2-dialkyl and spiro[1,3-benzodithiole-2,1'-cycloalkanes] with lead tetraacetate gave mainly sulfoxides and disulfoxides. The stereochemistry of these products was elucidated by n.m.r. spectroscopy. Oxidation of 2-methyl-2-aryl derivatives gave sulfoxides as minor products; here the main products were derived from attack on the methyl group forming acetoxy, diacetoxy, formyl and carboxylic acid derivatives and ring cleavage products. 2,2-Diaryl derivatives also formed small amounts of sulfoxides but ring cleavage products were predominant. Monosubstituted benzodithioles were very reactive and produced a variety of oxidation products, mostly unidentified.

The Synthesis of Some Carbohydrate-Derived Precursors to Tylonolide, the Aglycon of the Antibiotic Tylosin

1990 ◽  
Vol 43 (10) ◽  
pp. 1681 ◽  
Author(s):  
AB Hughes ◽  
RV Stick ◽  
DMG Tilbrook
Keyword(s):  
Carboxylic Acid ◽  
Methyl Group

Treatment of methyl 2,3-anhydro-4,6-O-benzylidene-α-D-alloside with the anion derived from trimethyl(prop-1-ynyl)silane, allylmagnesium chloride or isobutenylmagnesium chloride introduces a three- or four- carbon substituent at C2 of the sugar. In each case, a hydroboration-oxidation sequence helps convert the centre of unsaturation in the new substituent into a carboxylic acid residue. Subsequent manipulations allow the introduction ofanother carbon at C6 of the sugar to give a highly functionalized precursor to the C1-C9 fragment of tylonolide, the aglycon of the antibiotic tylosin. Attempts at the introduction of an axial methyl group at C4 of the extended sugar also described.

Pteridines CI Synthesis and Properties of Lumazine-6- and -7-carboxylic Acids

Pteridines ◽  
1993 ◽  
Vol 4 (4) ◽  
pp. 178-186 ◽  
Author(s):  
Roland Eisele ◽  
Keiichi Aritomo ◽  
Wolfgang Pfleiderer
Keyword(s):  
Carboxylic Acid ◽  
Carboxylic Acids ◽  
Resonance Effect ◽  
Uv Spectra ◽  
High Yield ◽  
Methyl Group ◽  
Methyl Derivatives ◽  
Pyrimidine Moiety

Summary Lumazine-6-(8) and 7-carboxylic acid (23) and their N-methyl derivatives (12, 13, 21, 26, 28, 29) have been synthesized and characterized by the determination of their pK values and the UV spectra of the neutral, mono and dianion species. It was noticed that the acidities of the two N-H protons of the pyrimidine moiety are almost the same indicating that the dianions of 8 and 23, respectively, are I: 1 mixtures of the corresponding N-l and N-3 deprotonated forms. The lumazine-7-carboxylic acids (23, 26, 28, 29, 31, 33) are in comparison to their 6-carboxyJic acid counterparts (8, 12, 13, 21, 39) stronger acids by about I pK unit due to the resonance effect of the 4-oxo function on C-7 but not C-6. Alkaline KMn04 oxidation of 6.7-dimethyl-Iumazine (30) forms expectedly 6-methyl-Iumazine-7-carboxylic acid (31) in high yield according to the activation of the 7-methyl group by the electron-attracting 4-carbonyl residue.

Total synthesis of polyoximic acid

2001 ◽  
Vol 79 (11) ◽  
pp. 1812-1826 ◽  
Author(s):  
Stephen Hanessian ◽  
Jian-min Fu
Keyword(s):  
Double Bond ◽  
Carboxylic Acid ◽  
Total Synthesis ◽  
Wittig Reaction ◽  
2D Nmr ◽  
Amino Acid Derivative ◽  
Methyl Group ◽  
X Ray ◽  
X Ray Crystallography ◽  
Correct Structure

The structure and stereochemistry of polyoximic acid, a degradation product of polyoxins, was originally designated as trans-3-ethylidene-L-azetidine-2-carboxylic acid. However, total synthesis revealed that the correct structure was in fact cis-3-ethylidene-L-azetidine-2-carboxylic acid, which was confirmed by X-ray crystallography. The synthesis of the trans-isomer was also done and its identity was confirmed by X-ray analysis as well. The key step for constructing the four-membered ring was a rhodium catalyzed carbenoid insertion into the N—H bond of a beta-amino acid derivative. The stereoselectivity of the exo-double bond was controlled by conducting a Horner-Emmons-Wadsworth or a Wittig reaction to generate the trans- and cis-isomers, respectively. Weinreb's amide was used as a latent methyl group for the separation of trans and cis mixtures. The double bond stereochemistry of polyoximic acid in the parent polyoxin was also confirmed to be cis by extensive 2D NMR studies.Key words: diazoinsertion, azetidine, olefination.

Where Is Bacosine in Commercially Available Bacopa monnieri?

Planta Medica ◽  
2020 ◽  
Vol 86 (08) ◽  
pp. 565-570
Author(s):  
Stefanie Ritter ◽  
Corinna Urmann ◽  
Rainer Herzog ◽  
Jan Glaser ◽  
Sebastian Bieringer ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Betulinic Acid ◽  
Ion Trap ◽  
2D Nmr ◽  
Acid Group ◽  
Bacopa Monnieri ◽  
Pharmacological Effects ◽  
Carboxylic Acid Group ◽  
Methyl Group ◽  
Reference Samples

Abstract Bacopa monnieri is an Ayurvedic plant with rising interest in the pharmacological effects of its extract and constituents, including flavonoids, saponins, and triterpenes such as cucurbitacins, betulinic acid, and bacosine. The latter two compounds are isomeric 3-hydroxy lupenoic acids, which vary only in the arrangement of the carboxylic acid group and the methyl group at C-27 and C-28 and the orientation of the hydroxy group at C-3. In this study, we have reinvestigated the contents of betulinic acid and bacosine, respectively, in extracts from various commercially available B. monnieri powders and food supplements. To our surprise, HPLC-ion trap time-of-flight analyses identified only betulinic acid, but not bacosine, in all extracts under study, which was verified by GC-MS, HPLC-ELSD, 1D NMR (1H,13C), and 2D NMR (1H,1H COSY, 1H,13C HMBC, 1H,13C HSQC, 1H,1H NOESY) experiments. Moreover, it turned out that commercially available reference samples of bacosine were structurally identical with betulinic acid.

5-HYDROXYQUINOLINE-8-CARBOXYLIC ACID—A COLORIMETRIC REAGENT FOR RUTHENIUM

1947 ◽  
Vol 25b (1) ◽  
pp. 49-55 ◽  
Author(s):  
J. G. Breckenridge ◽  
S. A. G. Singer
Keyword(s):  
Hydrogen Peroxide ◽  
Carboxylic Acid ◽  
Nitro Group ◽  
Diazonium Salt ◽  
Transmission Curve ◽  
Methyl Group ◽  
Colorimetric Reagent ◽  
New Compounds

5-Aminoquinoline-8-carboxylic acid was prepared from 8-methylquinoline by nitration in the 5-position, oxidation of the methyl group to carboxyl, and reduction of the nitro group to amino. The 5-aminoquinoline-8-carboxylic acid was converted to 5-hydroxyquinoline-8-carboxylic acid through the diazonium salt. Some of the properties of the two new compounds were determined.A transmission curve was established for solutions showing the colour developed by the reagent and ruthenium. The standard ruthenium solution used for this purpose contained the metal as it is obtained when distilled as the tetroxide and collected in hydrogen peroxide. Ruthenium in a solution as ammonium chlororuthenate could be determined from the same curve. One γ (1 × 10−6 gm.) of ruthenium in 50 ml. of solution may be quantitatively determined.

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