A new electronic-topological investigation of the relationship between chemical structure and ambergris odour.

An electronic-topological approach has been used to define an active ambergris fragment (AAF) which correctly describes the presence (or absence) of the ambergris odour of all 181 compounds investigated. The AAF consists of one oxygen atom and three carbon atoms (alpha, beta, gamma) which are separated by certain key distances and which possess certain atomic charges. The C(alpha) atom must bear at least one hydrogen atom (H(alpha)) which is located at a certain distance from one of the unshared electronic pairs of the oxygen atom.