Relative Configurations in Stereochemical Substructure Search

Abstract

Incorporation of stereochem. augmented connection tables into the CAS Registry File will make stereochem. substructure searching possible. A stereochem. search capability could be implemented by extending the present search system to det. the stereochem. validity of a topol. substructure match. However, much of the stereochem. in the Registry is described only in terms of relative configurations. When relative stereochem. is involved, it may not be obvious whether a topol. substructure match is stereochem. valid, since each relative set of stereoatoms may be viewed as having either of 2 chiralities. This type of problem can be represented as a weighted graph. By analyzing the corresponding graph, one is able to det. whether a topol. substructure match is stereochem. valid. A graph algorithm based upon a spin-glass analogy is described. [on SciFinder (R)]