A stereocontrolled synthesis of (−)-detoxinine from L -ascorbic acid

none3A stereoselective synthesis of (−)-detoxinine, the core unit of the detoxifying agent detoxin D1, is presented. The approach, characterized by the use of an inexpensive starting material and by the easy and stereoselective preparation of the key 4,5-disubstituted oxazolidin-2-one 11, proves to be a suitable alternative to the known procedures.openDELLE MONACHE G.; MISITI D.; ZAPPIA G.DELLE MONACHE, G.; Misiti, D.; Zappia, Giovann

Ricognizione chirale: aspetti chimici e farmaceutici

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Enantioselective HPLC as a powerful tool for modern developments in asymmetric organic synthesis

Strasbourg, 24-25/11/200

Polymeric composite chiral stationary phases of brush type.

The invention relates to novel polymeric composite chiral stationary phases of brush type suitable for the separation and/or the purification of enantiomers of organic and organometallic compounds. The invention further relates to methods for the preparation of such phases

High-performance liquid chromatography and its applications in the biological field.

A review with 3 refs. discussing esp. stationary phases and separation modes in high-performance liquid and gel chromatography [on SciFinder(R)

Nuovi macrocicli tetrammidici, procedimento per la loro preparazione e loro uso come recettori in fasi stazionarie chirali

Oggetto della presente invenzione è un macrociclo tertrammidico con molecola di formula (I) in cui: X e un alchile, un arile oppure un frammento polimetilenico -(ch2)n - dove n è un numero intero >= 2; Y è un gruppo allilossi, alcossi o arilmetossi; R è un idrogeno o un alchile, ed il suo enantiomero. Questa molecola viene preparata per reazione di una diammina chirale con la forma attivata di un diacido carbossilico aromatico. Il macrociclo tetrammidico della presente invenzione è utilizzabile come recettore chirale adatto alla separazione degli enantiomeri, e in generale di stereoisomeri, di composti organici ed organometallici, ed alla loro purificazione chimica. Questa molecola può essere usata in forma legata ad un supporto insolubile oppure in un sistema bifasico liquido/liquido

Chromatographic resolution of 1,2-amino alcohols on a chiral stationary phase containing N,N'-(3,5-dinitrobenzoyl)-trans-1,2-diaminocyclohexane. Theoretical and practical aspects

Optical resolution of several 1,2-diamino alcohols including some β-adrenergic blocking agents (β-blockers) was obtained by high-performance liquid chromatography on a chiral stationary phase containing 3,5-dinitrobenzoyl derivatives of trans-1,2-diaminocyclohexane (DACH-DNB) as chiral selectors. After formation of oxazolidin-2-one derivatives, racemic amino alcohols were completely resolved (α values ranging from 1.14 to 1.55 and R(s) from 1.2 to 3.3) on a 250 x 4.0 mm I.D. stainless-steel column. Further, some separations on chiral and achiral, coupled columns are reported: they show diastereo- and enantioselectivity for amino alcohols with more than one chiral centre. The method allows the utilization of both spectrophotometric and spectrofluorimetric detectors; moreover the availability of the (R,R),(S,S) selectors makes it possible to evaluate enantiomeric excesses higher than 99.9%. Some separations were also carried out with microbore columns (2.0 mm I.D.), which afforded the same performance

Direct resolution of racemic compounds on chiral microbore columns by Sub- and Supercritical Fluid Chromatography

Fast resolutions of racemic compounds (sulfoxides, amino alcohols, and α-methylarylacetic acids derivatives) were achieved on a chiral microbore column using carbon dioxide and a polar methanol/dioxane modifier. The stationary phase used in this study contains the 3,5-dinitrobenzoyl derivative of R,R(−)-1,2-diaminocyclohexane (DACH-DNB) as the chiral moiety, anchored to a silica gel surface by covalent bonds. Both thermodynamic and kinetic separation performances were improved by using a super- or subcritical carbon dioxide mobile phase (SFC, SubFC)