Cyclic Hydrocarbons with Side Chains

Rule A-61. General Principles

61.1 - Hydrocarbons more complex then those envisioned in Rule A-12, composed of cyclic nuclei and aliphatic chains, are named according to one of the methods given below. Choice is made so as to provide the name which is the simplest permissible or the most appropriate for the chemical intent.

61.2 - When there is no generally recognized trivial name for the hydrocarbon, then (1) the radical name denoting the aliphatic chain is prefixed to the name of the cyclic hydrocarbon, or (2) the radical name for the cyclic hydrocarbon is prefixed to the name of the aliphatic compound. Choice between these methods is made according to the more appropriate of the following principles: (a) the maximum number of substitutions into a single unit of structure; (b) treatment of a smaller of structure as a substituent into a larger. Numbering of double and triple bonds in chains or non-aromatic rings is assigned according to the principles of Rule A-3; numbering and citation of substituents are effected as described in Rule A-2.

61.3 - In accordance with the principle (a) of Part .2 of this rule, hydrocarbons containing several chains attached to one cyclic nucleus are generally named as derivatives of the cyclic compound; and compounds containing several side chains and/or cyclic radicals attached to one chain are named as derivatives of the acyclic compound.

Examples to Rule A-61.3

61.4 - In accordance with the principle (b) of Part .2 of this rule, a hydrocarbon containing a small cyclic nucleus attached to a long chain is generally named as a derivative of the acyclic hydrocarbon; and a hydrocarbon containing a small group attached to a large cyclic nucleus is generally named as a derivative of the cyclic hydrocarbon.

Examples to Rule A-61.4

61.5 - Recognized trivial names for composite radicals are used if they lead to simplifications in naming.

Examples to Rule A-61.5

61.6 - The following are among trivial names retained for cyclic hydrocarbons with side chains: "fulvene" (for methylenecyclopentadiene) and "stilbene" (for 1,2-diphenylethylene) (see also Rule A-12.1)

Examples to Rule A-61.6

See Recommendations'93 R-9.1, Table 19(a)

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