A New Twist in Eutectic Composition: Deracemization of a Racemic Compound Amino Acid by Viedma Ripening and Temperature Fluctuation

The composition of a crystalline diastereoisomer (eeDIA) is determined either by the eutectic composition of the racemic compound (eeEuRac) or that of resolving agent (eeEuRes) and the higher ee value has the more dominant effect.

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A new twist in eutectic composition: deracemization of a racemic compound amino acid by Viedma ripening and temperature fluctuation.

10.33774/chemrxiv-2021-38xnd-v4 ◽

2021 ◽

Author(s):

CRISTOBAL VIEDMA ◽

José Eugenio Ortíz

Keyword(s):

Temperature Fluctuation ◽

Solid Phase ◽

Enantiomeric Excess ◽

Eutectic Mixture ◽

Chiral Molecules ◽

Racemic Compound ◽

Chiral Compounds ◽

First Case ◽

New Finding ◽

New Ideas

Viedma ripening and temperature fluctuation are processes based on solution phase racemization and dissolution-growth of racemic or scalemic conglomerates resulting in solid-phase deracemization. The dissolution-growth process is performed by abrasive grinding in the first case and by the temperature fluctuation in the second. But both methods have the intrinsic drawback of being only applicable to conglomerates, accounting for only 10% of all chiral molecules and are not suitable for the 90% of chiral compounds that crystallize as racemic compound. Herein we show that the enantiomeric excess of the solution in the eutectic mixture formed by a racemic compound and one of its enantiomers in suspension changes dramatically by growth-dissolution of the crystals through grinding and temperature fluctuation, converting the racemic compound into the desired enantiomer. With this new finding the scope of Viedma ripening and temperature fluctuation could be significantly expanded and can shed new ideas about the origin of biological homochirality on earth.

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Eutectic Composition of a Chiral Mixture Containing a Racemic Compound

Organic Process Research & Development ◽

10.1021/op700018h ◽

2007 ◽

Vol 11 (2) ◽

pp. 293-293

Author(s):

Yaling Wang ◽

Rosario LoBrutto ◽

Robert W. Wenslow ◽

Ivan Santos

Keyword(s):

Eutectic Composition ◽

Racemic Compound

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Effect of the Enantiomeric Ratio of Eutectics on the Results and Products of the Reactions Proceeding with the Participation of Enantiomers and Enantiomeric Mixtures

Chemistry ◽

10.3390/chemistry2030051 ◽

2020 ◽

Vol 2 (3) ◽

pp. 787-795

Author(s):

Emese Pálovics ◽

Dorottya Fruzsina Bánhegyi ◽

Elemér Fogassy

Keyword(s):

Charge Distribution ◽

Eutectic Composition ◽

The Self ◽

Combined Effect ◽

Chiral Molecule ◽

Racemic Compound ◽

Enantiomeric Ratio

This perspective is focused on the main parameters determining the results of crystallization of enantiomers or enantiomeric mixtures. It was shown that the ratio of supramolecular and helical associations depends on the eutectic composition of the corresponding enantiomeric mixture. The M and P ratios together with the self-disproportionation (SDE) of enantiomers define the reaction of the racemic compound with the resolving agent. Eventually, each chiral molecule reacts with at least two conformers with different degrees of M and P helicity. The combined effect of the configuration, charge distribution, constituent atoms, bonds, flexibility, and asymmetry of the molecules influencing their behavior was also summarized.

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Eutectic Composition of a Chiral Mixture Containing a Racemic Compound

Organic Process Research & Development ◽

10.1021/op0501038 ◽

2005 ◽

Vol 9 (5) ◽

pp. 670-676 ◽

Cited By ~ 31

Author(s):

Yaling Wang ◽

Rosario LoBrutto ◽

Robert W. Wenslow ◽

Ivan Santos

Keyword(s):

Eutectic Composition ◽

Racemic Compound

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Faculty Opinions recommendation of Asymmetric amplification in amino acid sublimation involving racemic compound to conglomerate conversion.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.6932958.7146054 ◽

2010 ◽

Author(s):

Niles Lehman ◽

Aaron Burton

Keyword(s):

Amino Acid ◽

Racemic Compound

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Possibilities of Exploiting Kinetic Control in the Continuous Fractional Crystallization of Diastereomeric Mixtures

Symmetry ◽

10.3390/sym13081516 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1516

Author(s):

Dorottya Fruzsina Bánhegyi ◽

Elemér Fogassy ◽

Emese Pálovics

Keyword(s):

Fractional Crystallization ◽

Eutectic Composition ◽

Kinetic Resolution ◽

Kinetic Control ◽

Racemic Compound ◽

Rapid Crystallization ◽

Diastereomeric Salts ◽

Diastereomeric Purity

For rapid and kinetic control-influenced resolutions, it is advisable to choose a resolving agent with the highest possible eutectic composition (eeEuResAg). It may also be advantageous to add the crystalline resolving agent directly to the solution of the racemic compound. In addition, the use of a quasi-racemic resolving agent or amphoteric resolving agent can provide kinetic resolution. In some cases, the continuous fractional crystallization of diastereomeric salts requires the salt of the resolving agent (Ca2+, Na+, etc.) or other achiral additives (thiourea) that cause rapid crystallization and provide high diastereomeric purity. A further advantage may be the sequential use of the same resolving agent that is capable of forming crystalline diastereomers with both enantiomers when using kinetic control (tandem resolution).

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