Optical Resolution of Flavor/Fragrance Compounds by Chiral Supercritical Fluid Chromatography (SFC), and Determination of Absolute Stereochemistry using Vibrational Circular Dichroism (VCD)

Many of odor active compounds have various odor characteristics and unique chemical structures. Some of them have chirality based on chiral centers in their structure. Among them, there are different odor characteristics and odor thresholds between its enantiomers. Therefore, it is very important for flavor science to clarify the relationship between the absolute stereochemistry and the odor property. Two significant techniques are known for approaching to the study for chiral compounds; supercritical fluid chromatography (SFC) and vibrational circular dichroism (VCD). The former is one of optical resolution technique for racemic compounds using CO2 supercritical fluid. The latter is a recently developed technique for determination of absolute stereochemistry of organic compounds coupled with density functional theory (DFT) theoretical calculation. In this review, these two powerful tools for the investigation of chiral odor active compounds are introduced.