Appendix B. Rules for naming hetero-substituted cyclooctanes.

• Keep the numberings assigned to the conformations of cyclooctane fixed.
• Keep the orientation descriptors, such as equatorial and axial, assigned to the conformations of cyclooctane fixed.
• Find out the numbers that correspond to the heteroatoms within the ring.
• In case there is more than one way to read the numbers that correspond to the heteroatoms, e. g. 2P-6N in BC vs. 4N-8P in BC', choose the locant set that assigns the lowest numbers.
• If the numbers are the same and they just switch positions, e. g., 1N-5P in TBC vs. 1P-5N in TBC', the atom with the highest priority by Cahn-Ingold-Prelog rules gets the lowest number.
• If it is not clear which locant set assigns the lowest numbers e.g., 1,4,5,6 or 1,2,7,8 then the locant set that assigns the lowest number to the highest priority atom (CIP rules) is chosen. In the previous locant sets, if the highest priority atom can be either 2 or 4, then the locant set 1,2,7,8 should be chosen, despite the 7,8 being higher than 5 and 6.
• Read the numbers that correspond to the substituents on the ring.
• List the substituents on the ring preceded by the numbers and an appropriate prefix to indicate the number of times the substituent appears.
• Attach to the numbers the abbreviation of the appropriate orientational descriptor.
• For substituents on isoclinal positions, specify the R or S configuration of the atom.

By the previous rules the name for the following conformer:

Figure B.1. Example conformer.[fig.example.gif, 0.827KB ]

is 1,1,5e,8,8-pentamethyl-5a-oxo-1N-4,6-diO-5P-TBC.