2,3-Butanediol

• 2,3- butylene glycol
• Dimethylethylene
• Butane -2 ,3 -diol
• 2,3- dihydroxy

Slightly viscous, colorless, almost odorless liquid

Liquid

1.01 g · cm -3

19 ° C

180 ° C.

0.23 hPa ( 20 ° C)

Miscible with water

> 5000 mg · kg -1 ( LD50, rat, oral)

Template: Infobox chemical / molecular formula search available

2,3-butanediol is an aliphatic alcohol containing two hydroxyl groups (-OH) and having the empirical formula C4H10O2.

The arrangement of the hydroxyl groups can be spatially different. There are therefore three stereoisomers.

Occurrence

2,3- butanediol is produced, for example, in the brewing process by metabolism of diacetyl by the brewing yeast. Top-fermented beers can contain 2,3- butanediol from 50 to 130 mg / l.

Production and representation

2,3- butanediol is obtained, among others, by acid hydrolysis of corn sugar. Using biotechnological methods (sales with bacteria which are capable of mixed acid fermentation, such as Enterobacter aerogenes, see also 2,3- Butandiolgärung ) can also be presented purely the individual enantiomers.

Stereoisomerism

2,3-butanediol is chiral and includes two equally substituted stereogenic centers, so there are three stereoisomers: (R, R ) -2,3 -butanediol [ Synonym: D (-) -2,3- butanediol ], and to the enantiomers ( S, S) -2,3- butanediol [ synonym: L ( ) -2,3- butanediol ], and the meso-2 ,3 -butanediol.

The physical properties such as melting or boiling point of the three isomeric 2,3- butane diols differ and vary in mixtures of isomers with their composition.

Use

2,3-butanediol is generally used as a substitute for glycerin. It is also used as a solvent, usually for paints and as raw material for the production of butadiene, polymers and epoxy resins. In toiletries, it is used as an additive in hair tonics, hair washing and fixing, as well as in shaving cream and toothpaste.

Swell

• Diol