Parent Hydrides

R-2.4.4 Ring assemblies

Two or more identical cyclic systems (whether mono- or bicyclic) directly joined to each other by double or single bonds are called 'ring assemblies' when the number of such direct ring junctions is one less than the number of cyclic systems involved.

R- Assemblies of two identical cyclic systems are named in one of two ways: (a) by placing the prefix 'bi-' before the name of the corresponding substituent group (see R-2.5) enclosed in parentheses, if necessary (additive operation); or (b) by placing the prefix 'bi-' before the name of the corresponding parent hydride enclosed in parentheses, if necessary (conjunctive operation).

Examples to R-

R- Unbranched assemblies consisting of three or more identical ring systems are named by placing an appropriate numerical prefix 'ter-', 'quater-', 'quinque-', etc. (see R-, before the name of the parent hydride corresponding to the repetitive unit.

Examples to R-

As exceptions, unbranched assemblies consisting of benzene rings are named by using the appropriate numerical prefix with the substituent prefix name 'phenyl'.

Examples to R-

R-2.4.5 Cyclophanes
R-2.4.6 Natural product parent hydrides

This HTML reproduction is as close as possible to the published version [see IUPAC, Commission on Nomenclature of Organic Chemistry. A Guide to IUPAC Nomenclature of Organic Compounds (Recommendations 1993), 1993, Blackwell Scientific publications, Copyright 1993 IUPAC]. If you need to cite these rules please quote this reference as their source.

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