Comment on the recent controversy over the theory of chirality functions

Abstract

Derflinger,et al., have criticized the concept of qualitative completeness on the grounds that a chirality function may be qualitatively complete and still vanish identically for certain nonracemic, non-isomeric mixtures. It is pointed out that the functions considered by them are ones in which the full chirality function splits into parts which can be thought of as contributions from “effective fragments” of the molecule, and that their mixtures are indeed racemic in these fragments. The function can be augmented in a very simple way so as not to vanish for such mixtures, and the idea of qualitative completeness is in no way disturbed by this process.