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Bridged Hydrocarbons

Rule A-31. Bicyclic Systems

31.1 - Saturated alicyclic hydrocarbon systems consisting of two rings only, having two or more atoms in common, take the name of an open chain hydrocarbon containing the same total number of carbon atoms preceded by the prefix "bicyclo-". The number of carbon atoms in each of the three bridges connecting the two tertiary carbon atoms is indicated in brackets in descending order.

Examples to Rule A-31.1

31.2 - The system is numbered commencing with one of the bridgeheads, numbering proceeding by the longest possible path to the second bridgehead; numbering is then continued from this atom by the longer unnumbered path back to the first bridgehead and is completed by the shortest path from the atom next to the first bridgehead.

Examples to Rule A-31.2

31.3 - Unsaturated hydrocarbons are named in accordance with the principles set forth in Rule A-11.3 When after applying Rule A-31.2 a choice in numbering remains unsaturation is given the lowest numbers.

Examples to Rule A-31.3

(See Rule A-3.1 for double locants)

31.4 - Radicals derived from bridged hydrocarbons are named in accordance with the principles set forth in Rule A-11 The numbering of the hydrocarbon is retained and the point or points of attachment are given numbers as low as is consistent with the fixed numbering of the saturated hydrocarbon.

Examples to Rule A-31.4

(See Rule A-3.1 for double locants)

See Recommendations'93 R-2.4.2

Polycyclic Systems
Hydrocarbon Bridges


This HTML reproduction of Sections A, B and C of IUPAC "Blue Book" is as close as possible to the published version [see Nomenclature of Organic Chemistry, Sections A, B, C, D, E, F, and H, Pergamon Press, Oxford, 1979. Copyright 1979 IUPAC.] If you need to cite these rules please quote this reference as their source.

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