Chiral organic stereochemistry: Chiral HPLC, chiral auxiliaries, CD spectroscopy, X-ray crystallography, and light-powered chiral molecular motors.

In the studies of chiral organic stereochemistry, it is important to use enantiopure compounds. For this purpose, the chiral HPLC (High-Pressure Liquid Chromatography) columns containing chiral stationary phases were invented by Y. Okamoto and coworkers for enantio-separating various racemic compounds. In addition, the use of chiral auxiliaries is also useful for preparing enantiopure compounds and also for determining their absolute configurations, where covalent-bonded diastereomers are separated by HPLC on silica gel. In this review article, these HPLC methods will be discussed together with the applications to some interesting organic compounds including light-powered chiral molecular motors.