Representation of molecular configurations by CAST coding method

A configurational CAST (CAnonical representation of STereochemistry) coding method, which represents relative and absolute configuration, is described . The configurational CAST codes are constructed by canonical rotation of t he dihedral angles of the input structure before the CAST codes are assigne d. Using the configurational CAST, configurational differences can be disti nguished independently of conformational differences. Representation of ena ntiomers is also achieved by a mirror image conversion method. The CAST rep resentation shows the distinctive characteristics of several diastereomers and conformers that were examined. The method clearly represents the differ ences in configurations. Applications to organic molecules having complex s tereochemistry are also demonstrated.