3-Hydroxybutanal
Names

Preferred IUPAC name 3-Hydroxybutanal^[1]
Other names Acetaldol 3-Hydroxybutyraldehyde beta-Hydroxybutyraldehyde β-Hydroxybutyraldehyde
Identifiers
CAS Number	107-89-1 (R/S)^Y 117706-97-5 (R)^Y 117706-98-6 (S)^Y
3D model (JSmol)	Interactive image
ChemSpider	7609 (R/S)^Y 18915429 (R)^Y
ECHA InfoCard	100.003.210
EC Number	203-530-2
MeSH	3-hydroxybutanal
PubChem CID	7897 (R/S) 13061653 (R)
UNII	8C6G962B53^N
CompTox Dashboard (EPA)	DTXSID2050407
InChI InChI=1S/C4H8O2/c1-4(6)2-3-5/h3-4,6H,2H2,1H3^Y Key: HSJKGGMUJITCBW-UHFFFAOYSA-N^Y InChI=1/C4H8O2/c1-4(6)2-3-5/h3-4,6H,2H2,1H3 Key: HSJKGGMUJITCBW-UHFFFAOYAI
SMILES CC(O)CC=O
Properties
Chemical formula	C₄H₈O₂
Molar mass	88.106 g·mol⁻¹
Appearance	colorless liquid
Density	0.98 g/mL
Boiling point	162 °C (324 °F; 435 K)
Related compounds
Related aldehydes	Glycolaldehyde Lactaldehyde
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is ^YN ?) Infobox references

In organic chemistry, 3-hydroxybutanal (acetaldol, aldol) is an organic compound with the formula CH₃CH(OH)CH₂CHO and the structure H₃C−CH(OH)−CH₂−CH=O. It is classified as an aldol (R−CH(OH)−CHR'−C(=O)−R") and the word "aldol" can refer specifically to 3-hydroxybutanal. It is formally the product of the dimerization of acetaldehyde (CH₃CHO). A thick colorless or pale-yellow liquid, it is a versatile and valuable intermediate with diverse impacts.^[2] The compound is chiral although this aspect is not often exploited.

Production

[edit]

Acetaldehyde dimerizes upon treatment with aqueous sodium hydroxide:^[2]

2 CH₃CHO → CH₃CH(OH)CH₂CHO + H₂O

This is the prototypical aldol reaction.

Reactions and uses

[edit]

Dehydration of 3-hydroxybutanal gives crotonaldehyde. Distillation of 3-hydroxybutanal is sufficiently forcing to effect this conversion:^[2]

CH₃CH(OH)CH₂CHO → CH₃CH=CHCHO + H₂O

Hydrogenation of 3-hydroxybutanal gives 1,3-butanediol:

CH₃CH(OH)CH₂CHO + H₂ → CH₃CH(OH)CH₂CH₂OH

This diol is a precursor to 1,3-butadiene, precursor to diverse polymers.

Polymerization of 3-hydroxybutanal is also spontaneous, but can be stopped with the addition of water.

Aldol has been used in making perfumes and in ore flotation.^[3]

Former or niche uses

[edit]

It was formerly used in medicine as a hypnotic and sedative.^[4]

References

[edit]

^ "3-hydroxybutanal – Compound Summary". PubChem Compound. USA: National Center for Biotechnology Information. 26 March 2005. Identification and Related Records. Retrieved 13 October 2011.
^ ^a ^b ^c Kohlpaintner, Christian; Schulte, Markus; Falbe, Jürgen; Lappe, Peter; Weber, Jürgen (2008). "Aldehydes, Aliphatic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a01_321.pub2. ISBN 978-3527306732.
^ American Heritage Dictionary, 1973.
^ Hans Brandenberger, Robert A. A. Maes. (1997). Analytical Toxicology: For Clinical, Forensic, and Pharmaceutical Chemists. New York: de Gruyter.

Hypnotics/sedatives (N05C)

GABA_A

Alcohols	2M2B Chloralodol Ethanol (alcohol) Diethylpropanediol Ethchlorvynol Methylpentynol Trichloroethanol
Barbiturates	Allobarbital Amobarbital Aprobarbital Barbital Butabarbital Butobarbital Cyclobarbital Ethallobarbital Heptabarb Hexobarbital Mephobarbital Methohexital Narcobarbital Pentobarbital Phenallymal Phenobarbital Propylbarbital Proxibarbal Reposal Secobarbital Talbutal Thiamylal Thiopental Thiotetrabarbital Vinbarbital Vinylbital
Benzodiazepines	Brotizolam Cinolazepam Climazolam Clonazolam Doxefazepam Estazolam Flubromazolam Flunitrazolam Flunitrazepam Flurazepam Flutemazepam Flutoprazepam Loprazolam Lormetazepam Midazolam Nimetazepam Nitemazepam Nitrazepam Nitrazolam Quazepam Temazepam Triazolam
Carbamates	Carisoprodol Emylcamate Ethinamate Hexapropymate Meprobamate Methocarbamol Phenprobamate Procymate Tybamate
Imidazoles	Etomidate Metomidate Propoxate
Monoureides	Acecarbromal Apronal (apronalide) Bromisoval Capuride Carbromal Ectylurea
Neuroactive steroids	Acebrochol Allopregnanolone Alphadolone Alphaxolone Eltanolone Hydroxydione Minaxolone Progesterone
Nonbenzodiazepines	Eszopiclone Indiplon Lirequinil Necopidem Pazinaclone Saripidem Suproclone Suriclone Zaleplon Zolpidem Zopiclone
Phenols	Propofol
Piperidinediones	Glutethimide Methyprylon Pyrithyldione Piperidione
Quinazolinones	Afloqualone Cloroqualone Diproqualone Etaqualone Mebroqualone Mecloqualone Methaqualone Methylmethaqualone Nitromethaqualone SL-164
Others	Acetophenone Acetylglycinamide chloral hydrate Bromide compounds Lithium bromide Potassium bromide Sodium bromide Centalun Chloral betaine Chloral hydrate Chloralose Clomethiazole Dichloralphenazone Gaboxadol Kavalactones Loreclezole Paraldehyde Petrichloral Sulfonylalkanes Sulfonmethane (sulfonal) Tetronal Trional Triclofos Sesquiterpene Isovaleramide Isovaleric acid Valerenic acid

GABA_B

H₁

Antihistamines	Captodiame Cyproheptadine Diphenhydramine Doxylamine Hydroxyzine Methapyrilene Perlapine Pheniramine Promethazine Propiomazine
Antidepressants	Serotonin antagonists and reuptake inhibitors Etoperidone Nefazodone Trazodone Tricyclic antidepressants Amitriptyline Doxepin Trimipramine, etc. Tetracyclic antidepressants Mianserin Mirtazapine, etc.
Antipsychotics	Typical antipsychotics Chlorpromazine Thioridazine, etc. Atypical antipsychotics Olanzapine Quetiapine Risperidone, etc.

α₂-Adrenergic

5-HT_2A

Antidepressants	Trazodone Tricyclic antidepressants Amitriptyline Doxepin Trimipramine, etc. Tetracyclic antidepressants Mianserin Mirtazapine, etc.
Antipsychotics	Typical antipsychotics Chlorpromazine Thioridazine, etc. Atypical antipsychotics Olanzapine Quetiapine Risperidone, etc.
Others	Niaprazine

Melatonin

Orexin

α₂δ VDCC

Others

Production

Reactions and uses

Former or niche uses

See also

References