Common and IUPAC Systems of Nomenclature of Organic Compounds (up to 10 Carbons Open Chain and Carbocyclic Compounds)

It is necessary to use a systematic approach for naming organic compounds as a result of the continuous and high number of discoveries in the field.

Chemistry does not always follow the IUPAC nomenclature guidelines since some compounds have extremely long names and complicated nomenclature as per the IUPAC nomenclature guidelines. The more trivial names are given to these compounds.

Nomenclature for Organic Chemistry according to IUPAC

Nomenclature for organic chemistry is developed by the International Union of Pure and Applied Chemistry (IUPAC) to identify organic chemical compounds following the organization's recommendations. A version of this article appeared in Organic Chemistry Nomenclature. It is ideal if every organic compound has a name that can be used to construct a clear structural formula. IUPAC also has a nomenclature for inorganic chemistry. Normal communications do not always follow the guidelines for naming compounds recommended by the International Union of Pure and Applied Chemistry, except for compounds that need to be defined without any ambiguity. As an example, ethanol is now commonly referred to as ethanol instead of ethyl alcohol under the new IUPAC names. If the molecules are relatively simple, they can be better understood than non-systematic names that have to be learned or reviewed. Although it is often shorter and clearer, the common or trivial name is often preferred. It is most common for non-systematic names to be derived from original compound sources. The names which are very long may be harder to remember than structural formulae.

Common nomenclature system

There is no systematic nomenclature for organic compounds in Trivial Nomenclature. A set of rules is not used to write trivial compound names. This system simplifies naming organic compounds. Toluene, toluene, and phenol are examples of this. It is often the case that compounds described by trivial nomenclature have shorter and simpler names than those described under IUPAC nomenclature. Therefore, this system has not gone out of style. Using this common name or trivial system, it is fairly easy for compounds to be referred to by their corresponding names. For example, the carboxylic acid present in tamarind is commonly known as tartaric acid. Tartaric acid would be described as 2,3-dihydroxy-1,4-butanedioic acid if it were IUPAC nomenclature.

IUPAC nomenclature

Under IUPAC's Guidelines, compounds must be named under the following steps:

• The longest chain rule - Identification and naming of the parent hydrocarbon must take place. Parent chains for compounds in question are generally those containing the longest chains of carbon atoms, whether they are straight chains or chains of varying shapes.
• Substituents with multiple instances - Some prefixes that indicate the total number of the same substituents present in an organic compound, such as di, tri, etc.
• There are several substituents present at the same position and they are named - The substituent groups are arranged in ascending order alphabetically when two different substituent groups are found at the same position of the organic compound.
• Different substituent names - The IUPAC nomenclature of the organic compounds in question lists the corresponding substituents arranged alphabetically by their names.
• The lowest set of locants - Natural numbers must be used to number the carbon atoms in the parent hydrocarbon chain, starting at the end and using the lowest number to identify the carbon atom which contains the substituents.
• Naming complex substances - Carbon groups that are attached to substituted alkyl groups in organic compounds with branched structures are numbered as one while the carbon that is attached to the substituted group is referred to as a substituted alkyl group. The IUPAC nomenclature of these compounds must include brackets for branched and complex substituents.

As an example of the format of the IUPAC Name for the compound, you could write:
Locant + Prefix + Root + Locant + Suffix

Nomenclature for 10 carbon open chain and carbocyclic compounds

Before you can name organic compounds, it is important to memorize a few basic names. The names of alkanes are discussed below. According to what you have chosen to be the parent chain, the base part of the name represents its carbon count. Parent chains contain at least one type of functional group, as indicated by their suffix. A substituent is another group that attaches to a parent chain.

Alkanes – saturated hydrocarbons

The table below presents the names of straight-chain saturated hydrocarbons for chains containing up to 10 carbons. If a hydrogen atom from the end of the chain is removed, the substituted compound is named by changing -ane to -yl.

No. of Carbon atoms	Name
1	Methane.
2	Ethane.
3	Propane.
4	Butane.
5	Pentane.
6	Hexane.
7	Heptane.
8	Octane.
9	Nonane.
10	Decane.

Alkyl halides

A chain of alkane has halogens as a substituent. Halo- substituents are ranked similarly to alkyl substituents in the parent chain. Halogens are represented by the following:

F	Floro-
Cl	Chloro-
Br	Bromo-
I	Iodo-

Alkenes and alkynes – unsaturated hydrocarbons

The presence of double bonds is indicated when you substitute -ene for -ane. Double bonds are named using the suffix -adiene, -atriene, etc. It includes a prefix that indicates the number of double bonds if there is more than one. Triple bonds are named with the suffix -yne. By convention, the position of the multiple bonds within the parent chain precedes the number(s) of the first carbon of the multiple bonds.

Alcohols

The suffix -ane is replaced with -anol when naming alcohols. When there is more than one hydroxyl group present (-anediol, -anetriol, etc.), a prefix also indicates this. Those groups are indicated on the parent chain by putting the number(s) that correspond to the location(s) directly before the base name (as with alkenes).

Ethers

Ethers should only be named using their common names. Oxygen is attached to two alkyl groups, and the names are arranged alphabetically, with space between them and followed by ether. In the presence of identical alkyl groups, the prefix di- is used.

Aldehydes

The suffix -ane is substituted for -anal to identify aldehydes. Two or fewer of these groups may be found on the parent chain because they must be at the ends. A suffix that includes a prefix indicates the number of -CHO groups present is added if there are multiple -CHO groups. Because -CHO is at the end of the chain, it does not need to be stated because C-1 is automatically assigned.

Ketones

The suffix -ane is replaced with the suffix -anone when naming ketone molecules. Carbonyl groups (C=O) can have two, three, four, five, or more groups (for example, -anetrione, -anedione, etc.). If the carbonyl group(s) are located on the parent chain, the numeral(s) corresponding to the position(s) is/are shown directly before the base name (as in alkenes).

Carboxylic acids

The carboxylic acids are named based on the number of carbons in the longest continuous chain that includes the carboxyl group and on the substitution of the suffix -ane for the alkane ending. The parent chain should contain no more than two -COOH groups since they should be present at both ends. It is possible to expand the suffix to include a prefix that describes the number of -COOH groups present in the compound (-anedioic acid). In this group, the carbon is automatically assigned to carbon-1 since it will be at the end of the parent chain. Therefore, its position does not need to be specified.

Esters

These names can be derived from the carboxylic acid contained in the name.



With the -yl suffix, Alkyl groups are known as substituents. Space follows this name. By replacing the carboxylic acid suffix with -ate, we can name the acyl part of the name (what is leftover).

Amines

The amines should only be named by their common names. Alternative names are ethers. The alkyl (R) groups are listed alphabetically alongside the nitrogen group, but there are no spaces between the names. An amine is added after the nitrogen group. When the alkyl groups of two or three molecules are the same, di- and tri- are used.
Examples -

Get subject wise printable pdf documentsView Here

Share

Tweet

Share

Pin it

Share