2,3-Butanediol

2,3-Butanediol

Names
IUPAC name Butane-2,3-diol
Other names 2,3-Butylene glycol Dimethylene glycol 2,3-Dihydroxybutane Butan-2,3-diol
Identifiers
CAS Number	513-85-9 Y 19132-06-0 (2S,3S)-(+) N 24347-58-8 (2R,3R)-(-) N 5341-95-7 (2R,3S) N
3D model (Jmol)	Interactive image
ChEBI	CHEBI:62064 N
ChemSpider	257 Y
ECHA InfoCard	100.007.431
EC Number	208-173-6
PubChem CID	262
InChI InChI=1S/C4H10O2/c1-3(5)4(2)6/h3-6H,1-2H3 Key: OWBTYPJTUOEWEK-UHFFFAOYSA-N
SMILES CC(C(C)O)O
Properties
Chemical formula	C4H10O2
Molar mass	90.121 g/mol
Appearance	nearly colorless solid or liquid
Odor	odorless
Density	0.987 g/mL
Melting point	19 °C (66 °F; 292 K)
Boiling point	177 °C (351 °F; 450 K)
Solubility in water	miscible
Solubility	soluble in alcohol, ketones, ether
log P	-0.92
Vapor pressure	0.23 hPa (20 °C)
Acidity (pKa)	14.9
Refractive index (nD)	1.4366
Thermochemistry
Specific heat capacity (C)	213.0 J/K mol
Std enthalpy of formation (ΔfHo298)	-544.8 kJ/mol
Hazards
EU classification (DSD)	Flammable (F)
R-phrases	R11
S-phrases	(S2) S7 S16
NFPA 704	1 1 0
Flash point	85 °C (185 °F; 358 K)
Autoignition temperature	402 °C (756 °F; 675 K)
Lethal dose or concentration (LD, LC):
LD50 (median dose)	5462 mg/kg (rat, oral)
Related compounds
Related butanediols	1,4-Butanediol 1,3-Butanediol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

2,3-Butanediol is a organic compound with the formula is (CH₃)₂(CHOH)₂. 2,3-Butanediol has three stereoisomers, all of which are colorless, viscous liquids. Butanediols have applications as precursors to various plastics and pesticides.

Of the three stereoisomers, two are enantiomers (levo- and dextro-2,3-butanediol) and one is a meso compound. The enantiomeric pair have (2R, 3R) and (2S, 3S) configurations at carbons 2 and 3, while the meso compound has configuration (2R, 3S) or, equivalently, (2S, 3R).

2,3-Butanediol is prepared by hydrolysis of 2,3-butene oxide:

The isomer distribution depends on the stereochemistry of the epoxide.

The meso isomer is used to combine with naphthalene-1,5-diisocyanate. The resulting polyurethane is called "Vulkollan".

The (2R,3R)-stereoisomer of 2,3-butanediol is produced by a variety of microorganisms in a process known as butanediol fermentation. It is found naturally in cocoa butter, in the roots of Ruta graveolens, sweet corn, and in rotten mussels. It is used in the resolution of carbonyl compounds in gas chromatography.

During World War II research was done towards producing 2,3-butanediol by fermentation in order to produce 1,3-butadiene, the monomer of the polybutadiene used in a leading type of synthetic rubber.

7. C. De Mas, N. B. Jansen, G. T. Tsao (1988). "Production of optically active 2,3-butanediol by Bacillus polymyxa." Biotechnol. Bioeng. 31(4): 366-77.