Suffixes, IUPAC system

A chemical name typically has four parts in the IUPAC system of nomenclature prefix, locant, parent, and suffix. The prefix specifies the location and identity of various substituent groups in the molecule, the locant gives the location of the primary functional group, the parent selects a main part of the molecule and tells how many carbon atoms are in that part, and the suffix identifies the primary functional group. 

Simple alcohols are named by the IUPAC system as derivatives of the parent alkane, using the suffix -ol. 

Primary amines are named in the IUPAC system in several ways. For simple amines, the suffix -amine is added to the name of the alkyl substituent. You might also recall from Chapter 15 that phenylamine, C6HSNH2, has the common name aniline. 

Amines are organic derivatives of ammonia. They are named in the IUPAC system either by adding the suffix -amine to the name of the alkyl substituent or by considering the amino group as a substituent on a more complex parent molecule. 

The IUPAC rules assign names to unbranched alkanes as shown in Table 2.2. Methane, ethane, propane, and butane are retained for CH4, CH3CH3, CH3CH2CH3, and CH3CH2CH2CH3, respectively. Thereafter, the number of carbon atoms in the chain is specified by a Latin or Greek prefix preceding the suffix -ane, which identifies the compound as a member of the alkane family. Notice that the prefix n- is not part of the IUPAC system. The IUPAC name for CH3CH2CH2CH3 is butane, not n-butane. 

Unsubstituted aliphatic dicarboxylic acids. HOOC (CH ) COOH. are most often referred to by their trivial names for n = 2 to 10 (Table I). Higher homologucs are named using the IUPAC system by adding the suffix dioic to the parent hydrocarbon. 

By the IUPAC system, the suffix -ol for OH is added to the name of the parent hydrocarbon. N otice that alkane- + -ol becomes alkanol, with the e omitted ... 

The system of naming now used was devised by the International Union of Pure and Applied Chemistry, abbreviated IUPAC. In the IUPAC system, a chemical name has three parts prefix, parent, and suffix. The parent name tells how many carbon atoms are present in the longest continuous chain the suffix identifies what family the molecule belongs to and the prefix (if needed) specifies the location of various substituent groups attached to the parent chain ... 

In the IUPAC system of nomenclature, the suffix for alcohols is -ol. Alcohols are classified as primary, secondary, or tertiary depending on whether one, two, or three organic groups are attached to the hydroxyl-bearing carbon. The nomenclature of alcohols and phenols is summarized in Secs. 7.1-7.3. 

Alcohols are compounds that contain a hydroxy group (—OH). Common names for simple alcohols use the name of the alkyl group followed by alcohol, such as ethyl alcohol or isopropyl alcohol. In the IUPAC system, alcohols are given the name of the hydrocarbon from which they are derived, with the suffix -ol replacing the final e of the name. The longest chain that contains the carbon bonded to the hydroxy group is chosen as the root and numbered so that this carbon has the lowest possible number. 

The IUPAC system provides unique names for alcohols, based on rules that are similar to those for other classes of compounds. In general, the name carries the -ol suffix, together with a number to give the location of the hydroxyl group. The formal rules are summarized in the following three steps ... 

Common names use the names of R or Ar as separate words, along with the word ketone. The IUPAC system replaces the -e of the name of the longest chain by the suffix -one. 

The common method of naming aldehydes corresponds very closely to that of the related acids (see Carboxylic acids), in that the term aldehyde is added to the base name of the acid. For example, formaldehyde (qv) comes from formic acid, acetaldehyde (qv) from acetic acid, and butyraldehyde (qv) from butyric acid. If the compound contains more than two aldehyde groups, or is cyclic, the name is formed using carbaldehyde to indicate the functionality. The IUPAC system of aldehyde nomenclature drops the final e from the name of the parent acyclic hydrocarbon and adds al. If two aldehyde functional groups are present, the suffix - dial is used The prefix formyl is used with polyfunctional compounds. Examples of nomenclature types are shown in Table 1. 

The longest carbon chain containing the carbonyl group is selected and numbered starting with the carbon atom nearest the carbonyl group. If substitutents are present on the main chain, they are indicated by number of the carbon atoms to which they are attached. The number of the carbon atom of the carbonyl group is added to the front of the ketone. The IUPAC system replaces the -e of the name of the corresponding alkane by the suffix -one. 

We will use preferentially the current IUPAC nomenclature. On replacing a carbon atom in an aromatic hydrocarbon by a heteroatom, one can name the resulting system by combining the heteroatom s name (using the suffix a for the heteroatom) with the name of the hydrocarbon, e.g., pyridine may be called azabenzene. However, on replacing a heteroatom by another one, the new heteroatom s name... 

A complete dichotomy between bond order and other functionality. This is in contrast to IUPAC s organic nomenclature, which uses morphemic suffixes to specify both degree of bond unsaturation (ane, -ene, and -yne), and also selected functional groups (-one, -al, etc.). In the proposed system, on the other hand, the individual chemical symbols for atoms alternate with bond descriptors (small integers or selected symbols). In particular, traditional single, double and triple bonds are... 

All enzymes are named according to a classification system designed by the Enzyme Commission (EC) of the International Union of Pure and Applied Chemistry (IUPAC) and based on the type of reaction they catalyze. Each enzyme type has a specific, four-integer EC number and a complex, but unambiguous, name that obviates confusion about enzymes catalyzing similar but not identical reactions. In practice, many enzymes are known by a common name, which is usually derived from the name of its principal, specific reactant, with the suffix -ase added. Some common names do not even have -ase appended, but these tend to be enzymes studied and named before systematic classification of enzymes was undertaken. 

A double bond between two carbon atoms indicates the site, and possibly type, of hydrogen unsaturation. When double bonds are present, the suffix anoic is changed to enoic, dienoic, or trienoic to indicate the number of bonds. The location of the first carbon in the double bond is indicated by a number preceding the systemic name. Under International Union of Pure and Applied Chemistry (IUPAC) convention, stearic, oleic, linoleic, and linolenic acids are called octadecanoic, 9-octadecenoic, 9,12-octadecadienoic, and 9,12,15-octadecatrienoic acids, respectively. 

A newer IUPAC naming system places the number locant of the double bond immediately before the -ene suffix (not used in this book). 

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