We have developed a new computer system CAST/CNMR for accurate13C-NMR chemical shift prediction with considering stereochemical information by using of CAST coding method. CAST is a new canonical coding method for representation of 3D structures. Conformational CAST and configurational CAST are available in CAST/CNMR system, together with CANOST which is a coding method for planar structures. Ring-size information is also available in the system. Most of 13C-NMR chemical shift values are predicted with high accuracy by considering configurational information and solvent effects. Applications of CAST/CNMR to diastereomeric sesterterpenoids are also presented.
