scholarly journals Asymmetric Meerwein-Ponndorf-Verley reduction of long chain keto alkanoic acid methyl esters

2007 ◽  
Vol 72 (5) ◽  
pp. 421-427 ◽  
Author(s):  
Çelik Onar ◽  
Belma Hasdemir ◽  
Ayse Yusufoğlu
Keyword(s):  
1H Nmr ◽  
Optical Rotation ◽  
Methyl Esters ◽  
Enantiomeric Excess ◽  
Enantiomeric Purity ◽  
Hydroxy Ester ◽  
Tetradecanoic Acid ◽  
Alkanoic Acid ◽  
Acid Methyl ◽  
Long Chain

3-, 7- and 13-Monoketo tetradecanoic acid methyl esters carrying a keto group at the ends and at the middle of the chain with 14 carbon atoms were reduced by a Meerwein-Ponndorf-Verley reaction in the presence of R-(+)-1,1'-binaphthalene- 2,2'-diol, 1,2:5,6-D-di-O-isopropylidene-D-mannitol and L-(-)-menthol. The highest enantiomeric purity of 65% ee was found for 13-hydroxy ester isomer. The enantiomeric excess was determined by 1H-NMR shift with Eu(tfc)3 and by optical rotation.

scholarly journals A Novel and Efficient Method for the Synthesis of Methyl (R)-10-Hydroxystearate and FAMEs from Sewage Scum

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 663
Author(s):  
Luigi di Bitonto ◽  
Valeria D’Ambrosio ◽  
Carlo Pastore
Keyword(s):  
Fatty Acid Methyl Esters ◽  
Methyl Esters ◽  
Enantiomeric Excess ◽  
Single Step ◽  
Acid Catalysts ◽  
Acid Methyl ◽  
Chloride Hexahydrate ◽  
Catalyst Temperature ◽  
Homogeneous Acid ◽  
Aluminum Chloride Hexahydrate

In this work, the transesterification of methyl estolides (ME) extracted from the lipid component present in the sewage scum was investigated. Methyl 10-(R)-hydroxystearate (Me-10-HSA) and Fatty Acid Methyl Esters (FAMEs) were obtained in a single step. A three-level and four factorial Box–Behnken experimental design were used to study the effects of methanol amounts, catalyst, temperature, and reaction time on the transesterification reaction using aluminum chloride hexahydrate (AlCl3·6H2O) or hydrochloric acid (HCl) as catalysts. AlCl3·6H2O was found quite active as well as conventional homogeneous acid catalysts as HCl. In both cases, a complete conversion of ME into Me-10-HSA and FAMEs was observed. The products were isolated, quantified, and fully characterized. At the end of the process, Me-10-HSA (32.3%wt) was purified through a chromatographic separation and analyzed by NMR. The high enantiomeric excess (ee > 92%) of the R-enantiomer isomer opens a new scenario for the valorization of sewage scum.

Stereoselective synthesis of unsaturated very long chain fatty acid methyl esters

1999 ◽  
Vol 40 (21) ◽  
pp. 4041-4044 ◽  
Author(s):  
Julie Defretin ◽  
Jairo Saez ◽  
Xavier Franck ◽  
Reynald Hocquemiller ◽  
Bruno Figadère
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Methyl Esters ◽  
Stereoselective Synthesis ◽  
Methyl Esters ◽  
Chain Fatty Acid ◽  
Long Chain Fatty Acid ◽  
Acid Methyl ◽  
Long Chain

Chemical Shift Nonequivalence of Enantiomers of Amino Acid Derivatives in 1H NMR and 19F NMR Spectroscopy Induced by L-Chirasil- Val.

1992 ◽  
Vol 47 (7) ◽  
pp. 1034-1036 ◽  
Author(s):  
Bernhard Koppenhoefer ◽  
Michael Hummel
Keyword(s):  
Amino Acid ◽  
Nmr Spectroscopy ◽  
Chemical Shift ◽  
Methyl Esters ◽  
Enantiomeric Purity ◽  
Peak Splitting ◽  
H Nmr ◽  
Acid Methyl ◽  
Amino Acid Methyl Esters

Enantiomers of N-trifluoroacetyl-amino acid methyl esters in CC14 solution, after addition of the chiral polysiloxane (L)-Chirasil-Val, display a chemical shift nonequivalence ΔΔδ in both 1H NMR and 19F NMR spectroscopy. The effects found for the leucine and valine derivatives can be correlated with the thermodynamic parameters of interaction in the undiluted system, as determined by gas chromatography. In CDC13 solution, no peak splitting was observed. The method is potentially useful for the determination of the enantiomeric purity of substrates of low volatility.

Heat capacities and thermal diffusivities of some n-alkanoic acid methyl esters

2019 ◽  
Vol 130 ◽  
pp. 33-37 ◽  
Author(s):  
Nataliya S. Bogatishcheva ◽  
Mars Z. Faizullin ◽  
Eugene D. Nikitin
Keyword(s):  
Methyl Esters ◽  
Heat Capacities ◽  
Alkanoic Acid ◽  
Acid Methyl ◽  
Thermal Diffusivities

Long-chain α–ω diols from renewable fatty acids via tandem olefin metathesis–ester hydrogenation

2017 ◽  
Vol 19 (7) ◽  
pp. 1678-1684 ◽  
Author(s):  
Angela Gonzalez-de-Castro ◽  
Elena Cosimi ◽  
Mae Joanne B. Aguila ◽  
Piotr Gajewski ◽  
Mike Schmitkamp ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Olefin Metathesis ◽  
Fatty Acid Methyl Esters ◽  
Methyl Esters ◽  
Acid Methyl ◽  
Long Chain

Long chain α–ω diols were readily accessed from renewable fatty acid methyl esters following an orthogonal tandem self-metathesis–ester hydrogenation protocol.

Sign in / Sign up

Export Citation Format

Share Document