trans -Crotonaldehyde

Structural formula
General
Surname	Trans crotonaldehyde
other names	(2 E ) -But-2-enal ( IUPAC ); trans -2-butenal; beta-methylacrolein; trans -propylene aldehyde; Acraldehyde; Aldehyde ether; trans -But-2-en-1-al; alpha-oxo-beta-butylene;
Molecular formula	C 4 H 6 O
Brief description	colorless liquid with a sharp, stuffy odor
External identifiers / databases
EC number	204-647-1
ECHA InfoCard	100.004.226
PubChem	447466
ChemSpider	394562
DrugBank	DB04381
Wikidata	Q416036
properties
Molar mass	70.09 g mol −1
Physical state	liquid
density	0.85 g cm −3
Melting point	−74 ° C
boiling point	102 ° C
Vapor pressure	24 h Pa (20 ° C); 37 hPa (30 ° C); 101 hPa (40 ° C); 157 hPa (50 ° C);
solubility	Easily soluble in water (176 g l −1 at 20 ° C); easily miscible with organic solvents;
Refractive index	1.4366 (20 ° C)
safety instructions
H and P phrases	H: 225-301-311-330-315-318-335-341-373-400
	P: 201-210-260-280-304 + 340 + 310-370 + 378
MAK	DFG : no classification, as a carcinogenic effect is suspected ; Switzerland: 0.34 ml m −3 or 1 mg m −3 ;
Thermodynamic properties
ΔH f 0	−138.7 kJ / mol
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

trans -Crotonaldehyde is an organic-chemical compound from the group of unsaturated aldehydes . It is a structural isomer of crotonaldehyde , and cis -crotonaldehyde , which is technically far less important, also exists.

Occurrence

In nature, crotonaldehyde occurs primarily in croton oil , which is made from the plants of the genus Croton .

Extraction and presentation

Trans- protonaldehyde is produced on an industrial scale by a base-catalyzed aldol reaction of acetaldehyde . This is first converted into 3-hydroxybutanal (acetaldol) in an aldol addition reaction at mild temperatures . This is followed by an aldol condensation reaction at elevated temperature and with acetic acid as a catalyst to form trans- protonaldehyde.

The product is worked up by multi-stage distillation .

properties

Crotonaldehyde is a highly flammable liquid with a pungent odor. The compound is only slightly soluble in water, but readily soluble in common organic solvents. In the presence of oxygen it tends to form peroxides and to auto-oxidize .

Biological importance

In the human body, crotonaldehyde is also produced from acetaldehyde . Polyamines , normally natural protective substances of the cell , facilitate the conversion of acetaldehyde into crotonaldehyde after drinking alcohol . This in turn is strongly suspected of changing the DNA and being responsible for the development of cancer .

use

The oxidation of crotonaldehyde provides crotonic acid . The reduction of crotonaldehyde yields crotyl alcohol .

Web links

Commons : Trans-Crotonaldehyde - Collection of images, videos and audio files

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l Entry on trans-crotonaldehyde in the GESTIS substance database of the IFA , accessed on March 1, 2019(JavaScript required) .
↑ ^a ^b ^c Entry on (E) -But-2-enal. In: Römpp Online . Georg Thieme Verlag, accessed on March 1, 2019.
↑ ^a ^b ^c Entry on (E) -Crotonaldehyde in the Hazardous Substances Data Bank , accessed March 1, 2019.
↑ Entry on (E) -Crotonaldehyde in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 28, 2019. Manufacturers or distributors can expand the harmonized classification and labeling .
↑ Swiss Accident Insurance Fund (Suva): Limit values - current MAK and BAT values (search for 123-73-9 or 2-butenal ), accessed on September 14, 2019.
↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Standard Thermodynamic Properties of Chemical Substances, pp. 5-25.
^ Brockhaus ABC Chemie , VEB FA Brockhaus Verlag Leipzig 1965, p. 749.
^ Hans Beyer and Wolfgang Walter: Organische Chemie , S. Hirzel Verlag, Stuttgart 1984, ISBN 3-7776-0406-2 , p. 230.
^ Association of authors: Organikum , 19th edition, Johann Ambrosius Barth, Leipzig · Berlin · Heidelberg 1993, ISBN 3-335-00343-8 , p. 506.
^ William G. Young, Walter H. Hartung, Frank S. Crossley: Reduction of Aldehydes with Aluminum Isopropoxide , in: J. Am. Chem. Soc. , 1936 , 58 (1), pp. 100-102; doi : 10.1021 / ja01292a033 .

[GESTIS-1] ↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l Entry on trans-crotonaldehyde in the GESTIS substance database of the IFA , accessed on March 1, 2019(JavaScript required) .

[RÖMPP-2] Entry on (E) -But-2-enal. In: Römpp Online . Georg Thieme Verlag, accessed on March 1, 2019.

[HSDB-3] Entry on (E) -Crotonaldehyde in the Hazardous Substances Data Bank , accessed March 1, 2019.

[CLP_100.004.226-4] Entry on (E) -Crotonaldehyde in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 28, 2019. Manufacturers or distributors can expand the harmonized classification and labeling .

[5] Swiss Accident Insurance Fund (Suva): Limit values - current MAK and BAT values (search for 123-73-9 or 2-butenal ), accessed on September 14, 2019.

[CRC90_5_25-6] David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Standard Thermodynamic Properties of Chemical Substances, pp. 5-25.

[ABC_Chemie-7] Brockhaus ABC Chemie , VEB FA Brockhaus Verlag Leipzig 1965, p. 749.

[Beyer-8] Hans Beyer and Wolfgang Walter: Organische Chemie , S. Hirzel Verlag, Stuttgart 1984, ISBN 3-7776-0406-2 , p. 230.

[ORGANIKUM_19_345-9] Association of authors: Organikum , 19th edition, Johann Ambrosius Barth, Leipzig · Berlin · Heidelberg 1993, ISBN 3-335-00343-8 , p. 506.

[10] William G. Young, Walter H. Hartung, Frank S. Crossley: Reduction of Aldehydes with Aluminum Isopropoxide , in: J. Am. Chem. Soc. , 1936 , 58 (1), pp. 100-102; doi : 10.1021 / ja01292a033 .