Terpene Hydrocarbons

Terpene Hydrocarbons

Rule A-71. Acyclic Terpenes 

71.1 - The acyclic terpene hydrocarbons are named in a manner similar to that used for other unsaturated acyclic hydrocarbons when compounds with known structures are involved.

Examples to Rule A-71.1

Rule A-72. Cyclic Terpenes 

72.1 - The following structural types with their special names and special systems of numbering are used as the basic for the specialized nomenclature of monocyclic and bicyclic terpene hydrocarbons. The name "bornane" replaces camphane and bornylane; "norbornane" replaces norcamphane and norbornylane. 

Examples to Rule A-72.1

  

Nor-structures:
 

Rule A-73. Monocyclic Terpenes 

73.1 - Methane Type: Monocyclic terpene hydrocarbons of this type (ortho-, metha-, and para-isomers) are named menthane, menthene, menthadiene, etc., and are given the fixed numbering of menthane (Formula I). Such compounds substituted by additional alkyl groups are named in accordance with Rules A-11 and A-61.

Examples to Rule A-73.1

 

73.2 - Tetramethylcyclohexane Type: Monocyclic terpene hydrocarbons of this type are named systematically as derivatives of cyclohexane, cyclohexene, and cyclohexadiene (see Rule A-11)

Examples to Rule A-73.2

 

Rule A-74. Bicyclic Terpenes 

74.1 - Bicyclic terpene hydrocarbons having the skeleton of Formula II or this skeleton and additional side chains except methyl or isopropyl (or methylene if one methylene group is already present) are named as thujane, thujene, thujadiene, etc., and are given the fixed numbering shown for thujane (Formula II). Other hydrocarbons containing the thujane ring-skeleton are named from bicyclo[3.1.0]hexane and are given systematic bicyclo numbering (cf. Rule A-31).

Examples to Rule A-74.1

 

74.2 - Bicyclic terpene hydrocarbons having the skeleton of Formula III, IV, or V and additional side chains except methyl (or methylene if one methylene group is already present) are named, respectively, as carane, carene, caradiene, etc.; pinane, pinene, pinadiene, etc.; bornane, bornene, bornadiene, etc. They are given, respectively, the fixed numbering shown for carane (Formula III), pinane (Formula IV), and bornane (Formula V). Other hydrocarbons containing the ring-skeleton of carane, pinane, or bornane are named, respectively, from norcarane (Formula VI), norpinane (Formula VII), or norbornane (Formula VIII). These names are preferred to those from bicyclo[4.1.0.]heptane, bicyclo[3.1.1]heptane, or bicyclo[2.2.1]heptane. The nor-names are given systematic bicyclo numbering (cf. Rule A-31).

Examples to Rule A-74.2

  
 
 

74.3 - The name "camphene" is retained for the unsubstituted compound 2,2-dimethyl-3-methylenenorbornane.

Examples to Rule A-74.3

Rule A-75. Terpene Radicals 

75.1 - Simple acyclic hydrocarbon terpene radicals are named and numbered according to Rule A-3.5. The trivial names geranyl, neryl, linalyl and phytyl [for (E)-(7R, 11R)-3,7,11,15-tetramethyl-2-hexadecenyl] are retained for the unsubstituted radicals.75.2 - Radicals derived from menthane, pinane, thujane, carane, bornane, norcarane, norpinane, and norbornane are named in accordance with the principles set forth in Rules A-1.2 and A-11.4 except that the saturated radicals of pinane are named pinanyl, pinanylene, and pinanylidene. The numbering of the hydrocarbon is retained and the point or points of attachment, whether in the ring or side chain, are given numbers as low as is consistent with the fixed numbering of the hydrocarbon.

Examples to Rule A-75.2

  

75.3 - Radicals not named in Rules A-75.1 and A-75.2 are named as described in Rules A-11 and A-31.4.

Cyclic Hydrocarbons with Side Chains

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)