CSEARCH-STEREO: A new generation of NMR database systems allowing three-dimensional spectrum prediction

A new method for spectrum prediction is presented permitting incorporation of stereochemical features, which highly improves the quality of the obtained chemical shift values. The method is based on comparison of the query-structure with a reference library of ring skeletons, so that stereochemical interactions can be counted. The number of stereochemical interactions obtained over a five-bond sphere is used to produce a three-dimensional HOSE-code leading to a more accurate spectrum prediction. The advantages of this new concept will be discussed using examples from natural product chemistry.