High-performance liquid racemic mixture separation

Preparative Uses of MTPA Derivatives. Resolution of racemic compounds on a preparative scale is always a challenging endeavor. Conversion of the enantiomeric mixture into a mixture of diastereomers, each with unique physical properties, makes it possible to separate the components by a variety of physical methods, such as fractional recrystallization, distillation, or chromatography. One of the earliest uses of MTPA was the resolution of racemic alcohols via the separation of diastereomeric MTPA esters by preparative gas-liquid chromatography, followed by alcohol regeneration with Lithium Aluminum Hydride (eq 2). More frequently, diastereomeric MTPA esters have been separated by high performance liquid chromatography (HPLC), followed by al-... 

M. Xu and C.D. Tran, High-performance Liquid Chromatographic Separation of Racemic and Diastereomeric Mixtures of 2,4-Pentadienoate Iron Tricarbonyl Derivatives, /. Chromatogr., 543(1991) 233. 

We can also use high-performance liquid chromatography (HPLC, see page 436) to separate a racemic mixture, as long as the stationary medium (e.g. the solid that packs the column) is itself optically active. 

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