propiolaldehyde

{{Chembox

| ImageFile = Propinal.svg

| ImageSize = 200

| PIN = Prop-2-ynal

| OtherNames = Propynal; Propiolic aldehyde

| Section1 = {{Chembox Identifiers

| CASNo = 624-67-9

| CASNo_Ref = {{cascite|correct|CAS}}

| UNII = SJ8A65XF7N

| UNII_Ref = {{fdacite|correct|FDA}}

| PubChem = 12222

| ChemSpiderID = 11721

| SMILES = C#CC=O

| StdInChI=

| StdInChIKey =

}}

| Section2 = {{Chembox Properties

| C=3|H=2|O=1

| Appearance = colorless liquid

| Density = 0.9152 g/cm3

| MeltingPtC =

| BoilingPtC = 54-57

| Solubility =

}}

| Section3 = {{Chembox Hazards

| MainHazards =

| FlashPt =

| AutoignitionPt =

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Propiolaldehyde is an organic compound with molecular formula HC2CHO. It is the simplest chemical compound containing both alkyne and aldehyde functional groups. It is a colorless liquid with explosive properties.{{cite encyclopedia |surname1=P. Perlmutter |chapter=Propargyl Aldehyde |date=2001 |doi=10.1002/047084289X.rp262m |title=Encyclopedia of Reagents for Organic Synthesis |isbn=978-0471936237}}

Reactions

The compound exhibits reactions expected for an electrophilic alkynyl aldehyde. It is a dienophile and a good Michael acceptor. Grignard reagents add to the carbonyl center. Its explosive properties are attributed to the exothermicity of its polymerization.

Preparation

Its acetal can be prepared from acrolein.{{cite journal |doi=10.15227/orgsyn.059.0010|title=Alkyness via Phase Transfer-Catalyzed Dehydrohalogenatiion: Propiolaldehyde Diethyl Acetal|journal=Organic Syntheses|year=1979|volume=59|page=10|author=A. Le Coq and A. Gorgues}}

Occurrence in interstellar medium

Propynal has been observed in the interstellar medium. It is hypothesized to be formed from a carbon monoxide-acetylene complex.{{citation |last=Zhou |first=Li |author2=Ralf I. Kaiser |title=Pathways to Oxygen-Bearing Molecules in the Interstellar Medium and in Planetary Atmospheres: Cyclopropenone (c-C3H2O) and Propynal (HCCCHO) |journal=The Astrophysical Journal |year=2008 |volume=686 |issue=2 |pages=1493–1502 |doi=10.1086/591072 |doi-access=free }} Another possible pathway is through the reaction of propynylidyne (C3H) with water.{{citation |last=Xie |first=Hong-bin |author2=Chang-bin Shao |title=Radical-Molecule Reaction C3H + H2O on Amorphous Water Ice: A Promising Route for Interstellar Propynal |journal=The Astrophysical Journal |year=2007 |volume=670 |issue=1 |pages=449–456 |doi=10.1086/520757 |doi-access=free }}

Hazards

The compound is explosive, possibly because it tends to polymerize.

See also

References