The IUPAC (International Union of Pure and Applied Chemistry) nomenclature of organic chemistry is the standardized official naming rule of organic compounds, developed by the IUPAC.
The steps for naming an organic compound are as follows:
1. Identification of the parent hydrocarbon chain. This chain must obey the following rules, in order of precedence: It should have the maximum number of substituents of the suffix functional group. By suffix, it is meant that the parent functional group should have a suffix, unlike halogen substituents. If more than one functional group is present, the one with highest precedence should be used.
a) It should have the maximum number of multiple bonds.
b) It should have the maximum number of single bonds.
c) It should have the maximum length.
2. Identification of the parent functional group, if any, with the highest order of precedence.
3. Identification of the side-chains. Side chains are the carbon chains that are not in the parent chain, but are branched off from it.
4.Identification of the remaining functional groups, if any, and naming them by their ionic prefixes (such as hydroxy for -OH, oxy for =O, oxyalkane for O-R, etc.).
5. Different side-chains and functional groups will be grouped together in alphabetical order. (The prefixes di-, tri-, etc. are not taken into consideration for grouping alphabetically. For example, ethyl comes before dihydroxy or dimethyl, as the "e" in "ethyl" precedes the "h" in "dihydroxy" and the "m" in "dimethyl" alphabetically. The "di" is not considered in either case). When both side chains and secondary functional groups are present, they should be written mixed together in one group rather than in two separate groups.
6. Identification of double/triple bonds.
7. Numbering of the chain. This is done by first numbering the chain in both directions (left to right and right to left), and then choosing the numbering which follows these rules, in order of precedence.
a) Has the lowest-numbered locant (or locants) for the suffix functional group. Locants are the numbers on the carbons to which the substituent is directly attached.
b) Has the lowest-numbered locants for multiple bonds (The locant of a multiple bond is the number of the adjacent carbon with a lower number).
c) Has the lowest-numbered locants for prefixes.
8. Numbering of the various substituents and bonds with their locants. If there is more than one of the same type of substituent/double bond, a prefix is added showing how many there are (di – 2 tri – 3 tetra – 4 then as for the number of carbons below with 'a' added).
Yogita Ingle 6 years, 9 months ago
The IUPAC (International Union of Pure and Applied Chemistry) nomenclature of organic chemistry is the standardized official naming rule of organic compounds, developed by the IUPAC.
The steps for naming an organic compound are as follows:
1. Identification of the parent hydrocarbon chain. This chain must obey the following rules, in order of precedence: It should have the maximum number of substituents of the suffix functional group. By suffix, it is meant that the parent functional group should have a suffix, unlike halogen substituents. If more than one functional group is present, the one with highest precedence should be used.
a) It should have the maximum number of multiple bonds.
b) It should have the maximum number of single bonds.
c) It should have the maximum length.
2. Identification of the parent functional group, if any, with the highest order of precedence.
3. Identification of the side-chains. Side chains are the carbon chains that are not in the parent chain, but are branched off from it.
4.Identification of the remaining functional groups, if any, and naming them by their ionic prefixes (such as hydroxy for -OH, oxy for =O, oxyalkane for O-R, etc.).
5. Different side-chains and functional groups will be grouped together in alphabetical order. (The prefixes di-, tri-, etc. are not taken into consideration for grouping alphabetically. For example, ethyl comes before dihydroxy or dimethyl, as the "e" in "ethyl" precedes the "h" in "dihydroxy" and the "m" in "dimethyl" alphabetically. The "di" is not considered in either case). When both side chains and secondary functional groups are present, they should be written mixed together in one group rather than in two separate groups.
6. Identification of double/triple bonds.
7. Numbering of the chain. This is done by first numbering the chain in both directions (left to right and right to left), and then choosing the numbering which follows these rules, in order of precedence.
a) Has the lowest-numbered locant (or locants) for the suffix functional group. Locants are the numbers on the carbons to which the substituent is directly attached.
b) Has the lowest-numbered locants for multiple bonds (The locant of a multiple bond is the number of the adjacent carbon with a lower number).
c) Has the lowest-numbered locants for prefixes.
8. Numbering of the various substituents and bonds with their locants. If there is more than one of the same type of substituent/double bond, a prefix is added showing how many there are (di – 2 tri – 3 tetra – 4 then as for the number of carbons below with 'a' added).
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