Highly regio- and stereoselective reductions of carbonyl compounds in aqueous glycosidic media

Denis, Cécile; Laignel, Benoît; Plusquellec, Daniel; Marouille, Jean-Yves Le; Botrel, Alain

doi:10.1016/0040-4039(95)02094-2

Cited by 33 publications

(16 citation statements)

References 22 publications

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“…The enantioselectivity of the reaction was not examined. [144] Esters have also been reduced successfully with NaBH 4 under cationic micellar conditions. [145] The yields were dependent on the structure of the residues R and R' in RCOOR' as well as on the structure of the surfactant.…”

Section: Reductionsmentioning

confidence: 99%

Reactions in Micellar Systems

2005

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The notion of "green chemistry" has encouraged even synthetic organic chemists to include water as a solvent. Incredible selectivities and activities can be achieved through the addition of amphiphiles with a defined structure. The morphology of supramolecular assemblies or associates formed by surfactants vary according to the temperature and concentration. As a rule, reactions are typically conducted using simple spherical aggregates, that is, micelles in the nanometer range. The strong polarity gradient present between the hydrophilic surface and the hydrophobic core of the micelle means that both nonpolar and polar reagents can be solubilized. This solubilization results in reactants becoming more concentrated within the micelle than in the surrounding water phase and leads to an acceleration of the reaction and causes selective effects. The kinetic treatment of reactions in micellar systems can be accomplished by considering them as microheterogeneous two-phase systems.

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Section: Reductionsmentioning

confidence: 99%

Reactions in Micellar Systems

2005

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“…Werden ringförmige Ketone als Ausgangsverbindungen eingesetzt, verläuft die Reduktion bezüglich der cis / trans ‐Isomere erstaunlich stereoselektiv. Die Enantioselektivität wurde nicht untersucht 144…”

Section: Reaktionen In Micellenunclassified

Reaktionen in micellaren Systemen

2005

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Die Vorstellung einer “grünen Chemie” hat selbst den präparativ arbeitenden Organiker ermutigt, Wasser als Lösungsmittel in Betracht zu ziehen. Durch Zusätze von Amphiphilen bestimmter Struktur kann man erstaunliche Aktivitäten und Selektivitäten erzielen. Die von den Tensiden gebildeten Assoziate variieren in ihrer Morphologie je nach Temperatur und Konzentration. In der Regel arbeitet man im Bereich einfacher sphärischer Aggregate, der nanometergroßen Micellen. Da in Micellen ein starker Polaritätsgradient von der hydrophilen Oberfläche zum hydrophoben Kern vorliegt, können sowohl unpolare als auch polare Reaktanten solubilisiert werden. Dadurch kommt es oft im Vergleich zur umgebenden Wasserphase zu einer Konzentrierung der Reaktionspartner und damit zu einer Beschleunigung der Reaktion. Darüber hinaus treten selektive Effekte auf. Micellare Systeme können kinetisch als mikroheterogene Zweiphasensysteme behandelt werden.

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“…Stereoselective reductions of R-(À)-and S-( )carvone (1Á6 mmol) were carried out at room temperature with NaBH 4 (3Á2 mmol) in an aqueous solution of sucrose (1 mM) according to the literature (Herve Â du Penhoat et al 1991; Adams & Lerner 1992;Denis et al 1996). After stirring for 12 h the ®nal product was extracted with diethylether and the organic layer was evaporated under reduced pressure.…”

Section: Synthesis Of Carveol Isomersmentioning

confidence: 99%

Stereoselective Metabolism of the Monoterpene Carvone by Rat and Human Liver Microsomes

Jäger

Mayer

Platzer

et al. 2000

Journal of Pharmacy and Pharmacology

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The large amounts of carvone enantiomers consumed as food additives and in dental formulations justifies the evaluation of their biotransformation pathway. The in-vitro metabolism of R-(-)- and S-(+)-carvone was studied in rat and human liver microsomes using chiral gas chromatography. Stereoselective biotransformation was observed when each enantiomer was incubated separately with liver microsomes. 4R, 6S-(-)-Carveol was NADPH-dependently formed from R-(-)-carvone, whereas 4S, 6S-(+)-carveol was produced from S-(+)-carvone. Metabolite formation followed Michaelis-Menten kinetics exhibiting a significant lower apparent Km (Michaelis-Menten Constant) for 4R, 6S-(-)-carveol compared with 4S, 6S-(+)-carveol in rat and human liver microsomes (28.4+/-10.6 microM and 69.4+/-10.3 microM vs 33.6+/-8-55 microM and 98.3+/-22.4 microM). The maximal formation rate (Vmax) determined in the same microsomal preparations yielded 30.2+/-5.0 and 32.3+/-3.9 pmol (mg protein)(-1) min(-1) in rat liver and 55.3+/-5.7 and 65.2+/-4.3 pmol (mg protein)(-1) min(-1) in human liver microsomes. Phase II conjugation of the carveol isomers by rat and human liver microsomes in the presence of UDPGA (uridine S'-diphosphogluaronic acid) only revealed glucuronidation of 4R, 6S-(-)-carveol. Vmax for glucuronide formation was more than 4-fold higher in the rat liver compared with human liver preparations (185.9+/-34.5 and 42.6+/-7.1 pmol (mg protein)(-1) min(-1), respectively). Km values, however, showed no species-related difference (13.9+/-4.1 microM and 10.2+/-2.2 microM). This study demonstrated stereoselectivity in phase-I and phase-II metabolism for R-(-)- and S-(+)-carvone and might be predictive for carvone biotransformation in man.

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Highly regio- and stereoselective reductions of carbonyl compounds in aqueous glycosidic media

Cited by 33 publications

References 22 publications

Reactions in Micellar Systems

Reactions in Micellar Systems

Reaktionen in micellaren Systemen

Stereoselective Metabolism of the Monoterpene Carvone by Rat and Human Liver Microsomes

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