Pentanals

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The pentanals are a group of four isomeric saturated aldehydes with five carbon atoms. They have the general empirical formula C 5 H 10 O and a molar mass of 86.13 g / mol. They can also be thought of as being composed of a butyl and an aldehyde group  (-CHO); this means that all four variants ( structural isomers ) are represented, some of which differ significantly in their properties. 2-methylbutyraldehyde is chiral and also forms two stereoisomeric forms.

You are u. a. accessible by oxidation of the corresponding primary pentanols ( 1-pentanol , 3-methyl-1-butanol , 2-methyl-1-butanol and 2,2-dimethyl-1-propanol ). The analogous pentanoic acids are formed by further oxidation .

The pentanones have the same molar mass.

Pentanals
Surname Valeraldehyde Isovaleraldehyde 2-methylbutyraldehyde Pivalaldehyde
other names n -pentanal iso pentanal sec pentanal tert -pentanal
( S ) -2-methylbutyraldehyde ( R ) -2-methylbutyraldehyde
Structural formula Valeraldehyde Structural Formula V.1.svg Isovalerylaldehyde.svg 2-methylbutyric aldehyde (S) .svg 2-methylbutyric aldehyde (R) .svg Pivaldehyde.svg
CAS number 110-62-3 590-86-3 96-17-3 ( racemate ) 630-19-3
1730-97-8 33204-48-7
PubChem 8063 11552 7284 (racemate) 12417
6971248 a
Melting point −92 ° C −51 ° C <−60 ° C (racemate) 6 ° C
boiling point 103 ° C 92 ° C 91-93 ° C (racemate) 74 ° C (973 hPa)
a Note: The structural formula shown at PubChem has the wrong stereochemistry

IUPAC nomenclature

According to the IUPAC nomenclature, strictly speaking, only n -pentanal is a pentanal. 3-methyl-1-butanal, 2-methyl-1-butanal, and 2,2-dimethyl-1-propanal are therefore not pentanals.

Individual evidence

  1. ↑ a b Entry for CAS no. 110-62-3 in the GESTIS substance database of the IFA , accessed on December 1, 2012(JavaScript required) .
  2. ↑ a b Entry for CAS no. 590-86-3 in the GESTIS substance database of the IFA , accessed on December 1, 2012(JavaScript required) .
  3. ↑ a b Entry for CAS no. 96-17-3 in the GESTIS substance database of the IFA , accessed on December 1, 2012(JavaScript required) .
  4. ↑ a b Data sheet trimethylacetaldehyde from Sigma-Aldrich , accessed on December 1, 2012 ( PDF ).