Butanoic acids
Butanoic acids are alkanoic acids with four carbon atoms. They have the general empirical formula C 4 H 8 O 2 and a molar mass of 88.11 g / mol. There are two constitutional isomers :
| Butanoic acids | ||
| Surname | Butyric acid | Isobutyric acid |
| other names |
n -Butanoic acid butanoic acid ( IUPAC ) |
Isobutanoic acid 2-methylpropanoic acid ( IUPAC ) |
| Structural formula |  |
|
| CAS number | 107-92-6 | 79-31-2 |
| PubChem | 264 | 6590 |
| Molecular formula | C 4 H 8 O 2 | |
| Molar mass | 88.11 g mol −1 | |
| Physical state | liquid | |
| Melting point | −5 ° C | −46 ° C |
| boiling point | 163 ° C | 155 ° C |
nomenclature
According to the IUPAC - Nomenclature compounds having a are acyclic butane -Struktureinheit as unbranched main chain in which the terminal methyl group by a carboxy group is replaced referred to as butanoic acid. A permitted, but not preferred, alternative name is propanecarboxylic acid.
In addition to the parent compound butyric acid, there are therefore three other alkyl-substituted monocarboxylic acids without additional functional groups or unsaturated substituents, which are referred to as butanoic acids, but are not isomeric to butyric acid:
| Butanoic acids according to the IUPAC nomenclature | ||||
| Surname | Butanoic acid | 2-methylbutanoic acid | 3-methylbutanoic acid | 2-ethylbutanoic acid |
| other names | Butyric acid | 2-methylbutyric acid | Isovaleric acid | 2-ethylbutyric acid |
| Structural formula | |
 |
 |
|
| CAS number | 107-92-6 | 116-53-0 | 503-74-2 | 88-09-5 |
| PubChem | 264 | 8314 | 10430 | 6915 |
| Molecular formula | C 4 H 8 O 2 | C 5 H 10 O 2 | C 6 H 12 O 2 | |
| Molar mass | 88.11 g mol −1 | 102.13 g mol −1 | 116.16 g mol −1 | |
2-methylbutanoic acid is a chiral compound with two enantiomers .
Individual evidence
- ↑ a b Entry on butyric acid in the GESTIS substance database of the IFA , accessed on May 30, 2016(JavaScript required) .
- ↑ a b Entry on isobutyric acid in the GESTIS substance database of the IFA , accessed on May 30, 2016(JavaScript required) .
- ^ Carboxylic Acids and their Derivatives. Simple Carboxylic Acids Rule C-401. In: IUPAC Nomenclature of Organic Chemistry. Advanced Chemistry Development, Inc., Accessed August 13, 2020 .