2,3-Butanediol is the

organic compound In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. Th ...

with the formula (CH₃CHOH)₂. It is classified as a ''vic''-diol ( glycol). It exists as three stereoisomers, a chiral pair and the meso isomer. All are colorless liquids. Applications include precursors to various plastics and pesticides.

Isomerism

Of the three stereoisomers, two are

enantiomer In chemistry, an enantiomer ( /ɪˈnænti.əmər, ɛ-, -oʊ-/ ''ih-NAN-tee-ə-mər''; from Ancient Greek ἐνάντιος ''(enántios)'' 'opposite', and μέρος ''(méros)'' 'part') – also called optical isomer, antipode, or optical anti ...

s (levo- and dextro-2,3-butanediol) and one is a meso compound. The enantiomeric pair have (2''R'', 3''R'') and (2''S'', 3''S'') configurations at carbons 2 and 3, while the meso compound has configuration (2''R'', 3''S'') or, equivalently, (2''S'', 3''R'').

Industrial production and uses

2,3-Butanediol is prepared by hydrolysis of

2,3-epoxybutane 2,3-Epoxybutane is an organic compound with the formula CH3CH(O)CHCH3. It is an epoxide. The compound exists as three stereoisomers, a pair of enantiomers and the meso isomer. All are colorless liquids. Preparation and reactions 2,3-Epoxybutan ...

:Heinz Gräfje, Wolfgang Körnig, Hans-Martin Weitz, Wolfgang Reiß, Guido Steffan, Herbert Diehl, Horst Bosche, Kurt Schneider and Heinz Kieczka "Butanediols, Butenediol, and Butynediol" in ''Ullmann's Encyclopedia of Industrial Chemistry'', 2000, Wiley-VCH, Weinheim. :(CH₃CH)₂O + H₂O → CH₃(CHOH)₂CH₃ 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 Polyurethane (; often abbreviated PUR and PU) refers to a class of polymers composed of organic units joined by carbamate (urethane) links. In contrast to other common polymers such as polyethylene and polystyrene, polyurethane is produced from ...

is called "Vulkollan".

Biological production

The (2''R'',3''R'')- stereoisomer of 2,3-butanediol is produced by a variety of

microorganism A microorganism, or microbe,, ''mikros'', "small") and ''organism'' from the el, ὀργανισμός, ''organismós'', "organism"). It is usually written as a single word but is sometimes hyphenated (''micro-organism''), especially in old ...

s in a process known as

butanediol fermentation 2,3-Butanediol fermentation is anaerobic fermentation of glucose with 2,3-butanediol as one of the end products. The overall stoichiometry of the reaction is :2 pyruvate + NADH --> 2 CO2 + 2,3-butanediol. Butanediol fermentation is typical for t ...

. It is found naturally in

cocoa butter Cocoa butter, also called theobroma oil, is a pale-yellow, edible fat extracted from the cocoa bean. It is used to make chocolate, as well as some ointments, toiletries, and pharmaceuticals. Cocoa butter has a cocoa flavor and aroma. Its melt ...

, in the roots of '' Ruta graveolens'', sweet

corn Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maíz after tnq, mahiz), also known as corn (North American and Australian English), is a cereal grain first domesticated by indigenous peoples in southern Mexico about 10,000 years ago. The ...

, and in rotten

mussel Mussel () is the common name used for members of several families of bivalve molluscs, from saltwater and freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other edible clams, which ...

s. It is used in the resolution of carbonyl compounds in

gas chromatography Gas chromatography (GC) is a common type of chromatography used in analytical chemistry for separating and analyzing compounds that can be vaporized without decomposition. Typical uses of GC include testing the purity of a particular substanc ...

. During

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...

research was done towards producing 2,3-butanediol by fermentation in order to produce

1,3-butadiene 1,3-Butadiene () is the organic compound with the formula (CH2=CH)2. It is a colorless gas that is easily condensed to a liquid. It is important industrially as a precursor to synthetic rubber. The molecule can be viewed as the union of two v ...

, the

monomer In chemistry, a monomer ( ; '' mono-'', "one" + '' -mer'', "part") is a molecule that can react together with other monomer molecules to form a larger polymer chain or three-dimensional network in a process called polymerization. Classification ...

of the

polybutadiene Polybutadiene utadiene rubber BRis a synthetic rubber. Polybutadiene rubber is a polymer formed from the polymerization of the monomer 1,3-butadiene. Polybutadiene has a high resistance to wear and is used especially in the manufacture of ti ...

used in a leading type of

synthetic rubber A synthetic rubber is an artificial elastomer. They are polymers synthesized from petroleum byproducts. About 32-million metric tons of rubbers are produced annually in the United States, and of that amount two thirds are synthetic. Synthetic rubb ...

. It can be derived from the fermentation of sugarcane molasses. Fermentative production of 2,3-butanediol from carbohydrates involves a network of biochemical reactions that can be manipulated to maximize production. 2,3-butanediol has been proposed as a rocket fuel that could be created on Mars by means of cyanobacteria and E. coli, shipped from Earth, working on resources available at the surface of Mars.

Reactions

2,3-Butanediol undergo dehydration to form butanone (methyl ethyl ketone): :(CH₃CHOH)₂ → CH₃C(O)CH₂CH₃ + H₂O It can also undergo deoxydehydration to form

butene Butene, also known as butylene, is an alkene with the formula . The word ''butene'' may refer to any of the individual compounds. They are colourless gases that are present in crude oil as a minor constituent in quantities that are too small for ...

: :(CH₃CHOH)₂ + 2 H₂ → C₄H₈ + 2 H₂O

References

{{DEFAULTSORT:Butanediol, 2, 3- Alkanediols Vicinal diols