Commonly used methods include crystallization separation and distillation separation. Crystallization separation is a separation method based on differences in physical properties. By adjusting conditions such as solvent, temperature and concentration, crystallization separation of different stereoisomers can be achieved. Distillation separation is a separation method based on differences in boiling points. By controlling temperature and pressure, distillation separation of different stereoisomers can be achieved.
It depends from the nature or the stereoisomers: diastereomers (including E/Z isomerism) can be phisico-chimically separated (selective precipitation/crystallization, column chromatography, distillation), while enantiomers can only be separated on a chiral stationary phase (e.g., by preparative HPLC after optimizing the separation on the same stationary phase on analytical scale) or with chiral resolution agents (e.g. enantiopure chiral amine to generate diastereomeric salts of the two enantiomers of a chiral acid and then physico-chemical separation of such salts and re-acidification)
If these are enantiomers, chromatography with a chiral stationary phase will work. If these are geometric isomers, these may be separated by physical methods like crystallization.