Sigma-Aldrich is a leader in chiral products and services in chemical synthesis, drug discovery, and analytical assessment. Chiral chemistry is a core component for the synthesis of natural products and drugs and the quest to find chiral catalysts capable of achieving high selectivity for a variety of asymmetric transformations has been an ongoing endeavor for the past 40 years. Another aspect of chiral chemistry includes the development of chromatographic methods to separate enantiomers. Resolution and separation by chiral chromatography has become one of the most challenging and essential steps in the synthesis of chiral molecules and Sigma-Aldrich is proud to offer a vast array of Astec chiral stationary phases for this purpose. Chiral column screening, method optimization, and small-scale enantiomeric purification services are also available from Sigma-Aldrich.