Pure and Applied Chemistry

Abstract: These recommendations document the von Baeyer system for naming polycyclic ring systems described in Rules A-31, A-32 and B-14 of the Nomenclature of Organic Chemistry, Sections A, B, C, D, E, F and H, 1979 and R-2.4.2 of A Guide to IUPAC Nomenclature of Organic Compounds, 1993 and extend the system to cover more complex cases. It provides guidance on the naming of ring systems which previously the rules did not cover. The methods is to identify the main ring and main bridge which provide the basic bicyclic system and to number these atoms. Then all further bridges, whether or not they include additional atoms, are identified by indicating not only the number of atoms but also the two atoms to which the bridge is attached. The final name also indicated the number of rings and the total number of skeletal atoms in the ring systems. Heteroatoms, unsaturation and substituents are indicated in the usual way.