Organic Chemistry Nomenclature
Part 1. Hydrocarbon Nomenclature From International Union of Pure and Applied Chemistry (IUPAC)
General Form of IUPAC Nomenclature
[branching substituent(s)] Root [Suffix]
Rules: 1. Identify the longest continuous chain of carbon atoms. This chain determines the parent name (root) of the alkane. The parent suffix for alkanes is, not surprisingly, -ane. For chains of equal length, pick the one with the most substituents. (Note: I number all possibilities going from left to right – identify the longest chain) 2. Number the chain beginning at the end of the chain nearest any branching, thus obtaining the lower numbers in the same name. (Note: I number going from left to right and right to left, then identify at which carbons there are substituents) 3. Use these numbers to designate the location of the substituent groups. Substituent alkyl groups are referred to with suffix “-yl”. (i.e., an alkane substituent is an alkyl) 4. If an alkyl group appears more than once, use the prefixes di, tri, tetra, penta, hexa (2, 3, 4, 5, 6, respectively) for each type of alkyl group. 5. List the groups alphabetically (note: you can ignore this rule in Chem 123) 6. Numbers are separated from letters by dash (-). Multiple numbers are separated by commas (,).
Linear chain hydrocarbon roots: n = 1 | meth | | n = 5 | pent | | n = 8 | oct | n = 2 | eth | | n = 6 | hex | | n = 9 | non | n = 3 | prop | | n = 7 | hept | | n = 10 | dec | n = 4 | but | | | | | | |
Hydrocarbon Suffixes
Hydrocarbon Suffix
Alkane ane
Alkene ene
Alkyne yne
Common alkyl substituents CH3- methyl CH3CH2- ethyl CH3CH2CH2- propyl CH3CH2CH2CH2- butyl
Branched chains
Example 1
:
Rule 1. Identify the longest continuous chain of carbon atoms
SIX = hexane root
Rule 2. Number the chain beginning at the end of the chain nearest any branching
Substituent is at 2 position - lower
General Form of IUPAC Nomenclature
[branching substituent(s)] Root [Suffix]
Rules: 1. Identify the longest continuous chain of carbon atoms. This chain determines the parent name (root) of the alkane. The parent suffix for alkanes is, not surprisingly, -ane. For chains of equal length, pick the one with the most substituents. (Note: I number all possibilities going from left to right – identify the longest chain) 2. Number the chain beginning at the end of the chain nearest any branching, thus obtaining the lower numbers in the same name. (Note: I number going from left to right and right to left, then identify at which carbons there are substituents) 3. Use these numbers to designate the location of the substituent groups. Substituent alkyl groups are referred to with suffix “-yl”. (i.e., an alkane substituent is an alkyl) 4. If an alkyl group appears more than once, use the prefixes di, tri, tetra, penta, hexa (2, 3, 4, 5, 6, respectively) for each type of alkyl group. 5. List the groups alphabetically (note: you can ignore this rule in Chem 123) 6. Numbers are separated from letters by dash (-). Multiple numbers are separated by commas (,).
Linear chain hydrocarbon roots: n = 1 | meth | | n = 5 | pent | | n = 8 | oct | n = 2 | eth | | n = 6 | hex | | n = 9 | non | n = 3 | prop | | n = 7 | hept | | n = 10 | dec | n = 4 | but | | | | | | |
Hydrocarbon Suffixes
Hydrocarbon Suffix
Alkane ane
Alkene ene
Alkyne yne
Common alkyl substituents CH3- methyl CH3CH2- ethyl CH3CH2CH2- propyl CH3CH2CH2CH2- butyl
Branched chains
Example 1
:
Rule 1. Identify the longest continuous chain of carbon atoms
SIX = hexane root
Rule 2. Number the chain beginning at the end of the chain nearest any branching
Substituent is at 2 position - lower