Nomenclature unsaturation component

For monocyclic components other than benzene the nomenclature is based on that of the corresponding cycloalkanes. Prefixes of the type cyclopenta-, cyclohepta-, etc., are used, and for names of monocyclic base components the termination -ene is employed, this termination indicating maximum unsaturation in the whole system (not just a single double bond in the cycloalkene unit). Thus 15 and 16 are named as shown. 

Systems that do not meet all the above specifications, but the use of which is acceptable because of their convenience or the lack of suitable alternatives are the bridging nomenclature, system 4, method b (in which saturated bridging groups are permitted), the spiro method, 6a, ii (in which the components may be fully unsaturated or saturated and retain their original numberings), and system 7 for assemblies of identical cyclic components. 

With regard to spiro nomenclature, method 6a, i is applicable unless one at least of the components is a fused or bridged unit then method 6a, ii should be used. In using method 6a, ii it is not necessary to ensure that all units are either fully saturated or fully unsaturated a mixture of both types is frequently convenient, e.g., 50 and 52 (however, see Section II, B, 2, a, ii). 

Lipids with saturated fatty acids are called saturated fats and are commonly solids at room temperature (such as butter and shortening). Unsaturated fats contain one or more double bonds in their carbon—carbon chains. The cis and trans nomenclature we learned for alkenes applies Trans fats have H atoms on the opposite sides of the C=C double bond, and cis fats have H atoms on the same sides of the C=C double bond. Unsaturated fats (such as olive oil and peanut oil) are usually liquid at room temperature and are more often found in plants. For example, the major component (approximately 60 to 80%) of olive oil is oleic acid, as-CH3(CH2)7CH=CH(CH2)7COOH. 

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