Acetaldehyde

ethanalCH 3 CHOacetylaldehydeacetylaldehydesaldehyde metaboliteFormylmethanide
Acetaldehyde (systematic name ethanal) is an organic chemical compound with the formula CH 3 CHO, sometimes abbreviated by chemists as MeCHO (Me = methyl).wikipedia
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Aldehyde

aldehydesformylformyl group
Acetaldehyde (systematic name ethanal) is an organic chemical compound with the formula CH 3 CHO, sometimes abbreviated by chemists as MeCHO (Me = methyl).
In the past, aldehydes were sometimes named after the corresponding alcohols, for example, vinous aldehyde for acetaldehyde.

Acetaldehyde dehydrogenase

acetaldehyde dehydrogenase (acetylating)related enzymes
Consumption of disulfiram inhibits acetaldehyde dehydrogenase, the enzyme responsible for the metabolism of acetaldehyde, thereby causing it to build up in the body. In the liver, the enzyme alcohol dehydrogenase oxidizes ethanol into acetaldehyde, which is then further oxidized into harmless acetic acid by acetaldehyde dehydrogenase.
Acetaldehyde dehydrogenases are dehydrogenase enzymes which catalyze the conversion of acetaldehyde into acetic acid.

Hangover

hungoverhung overhangovers
It is also produced by the partial oxidation of ethanol by the liver enzyme alcohol dehydrogenase and is a contributing cause of hangover after alcohol consumption.
While the causes of a hangover are still poorly understood, several factors are known to be involved including acetaldehyde accumulation, changes in the immune system and glucose metabolism, dehydration, metabolic acidosis, disturbed prostaglandin synthesis, increased cardiac output, vasodilation, sleep deprivation and malnutrition.

Wacker process

Wacker oxidationWacker-Tsuji oxidationWacker
The main method of production is the oxidation of ethylene by the Wacker process, which involves oxidation of ethylene using a homogeneous palladium/copper system:
The Wacker process or the Hoechst-Wacker process (named after the chemical companies of the same name) refers to the oxidation of ethylene to acetaldehyde in the presence of palladium(II) chloride as the catalyst.

Alcohol (drug)

alcoholdrinkingdrink
It is also produced by the partial oxidation of ethanol by the liver enzyme alcohol dehydrogenase and is a contributing cause of hangover after alcohol consumption.
Alcohol also has toxic and unpleasant actions in the body, many of which are mediated by its byproduct acetaldehyde.

Disulfiram

Antabusetetraethylthiuram disulfideN,N,N'N'''-Tetraethylthiuram disulfide
Consumption of disulfiram inhibits acetaldehyde dehydrogenase, the enzyme responsible for the metabolism of acetaldehyde, thereby causing it to build up in the body.
In the body, alcohol is converted to acetaldehyde, which is then broken down by acetaldehyde dehydrogenase.

Alcohol dehydrogenase

liver alcohol dehydrogenasealcohol dehydrogenasesADH
It is also produced by the partial oxidation of ethanol by the liver enzyme alcohol dehydrogenase and is a contributing cause of hangover after alcohol consumption. In the brain, the enzyme catalase is primarily responsible for oxidizing ethanol to acetaldehyde, and alcohol dehydrogenase plays a minor role. In the liver, the enzyme alcohol dehydrogenase oxidizes ethanol into acetaldehyde, which is then further oxidized into harmless acetic acid by acetaldehyde dehydrogenase.
It catalyzes the oxidation of ethanol to acetaldehyde (ethanal):

Vinyl alcohol

EthenolInterstellar vinyl alcohol
The mechanism involves the intermediacy of vinyl alcohol, which tautomerizes to acetaldehyde. Like many other carbonyl compounds, acetaldehyde tautomerizes to give an enol (vinyl alcohol; IUPAC name: ethenol):
With the formula 2 CHH, it is a labile compound that converts to acetaldehyde.

Ethylene

etheneC 2 H 4 ethylene gas
The main method of production is the oxidation of ethylene by the Wacker process, which involves oxidation of ethylene using a homogeneous palladium/copper system:
Ethylene undergoes oxidation by palladium to give acetaldehyde.

Paraldehyde

trioxane
Three molecules of acetaldehyde condense to form "paraldehyde", a cyclic trimer containing C-O single bonds.
Paraldehyde is the cyclic trimer of acetaldehyde molecules.

Ethanol

alcoholbioethanolethyl alcohol
It is also produced by the partial oxidation of ethanol by the liver enzyme alcohol dehydrogenase and is a contributing cause of hangover after alcohol consumption. Before 1962, ethanol and acetylene were the major sources of acetaldehyde. In the liver, the enzyme alcohol dehydrogenase oxidizes ethanol into acetaldehyde, which is then further oxidized into harmless acetic acid by acetaldehyde dehydrogenase.
The metabolite acetaldehyde is responsible for much of the short term, and long term effects of ethyl alcohol toxicity.

Synthon

synthonsbuilding blocksynthetic and reactive equivalent
It is used primarily as a source of the "CH 3 C + H(OH)" synthon in aldol and related condensation reactions.

Acetylene

acetylene gasethyneC 2 H 2
Before 1962, ethanol and acetylene were the major sources of acetaldehyde.
In 1881, the Russian chemist Mikhail Kucherov described the hydration of acetylene to acetaldehyde using catalysts such as mercury(II) bromide.

Carbonyl group

carbonylcarbonyl compoundcarbonyls
Like many other carbonyl compounds, acetaldehyde tautomerizes to give an enol (vinyl alcohol; IUPAC name: ethenol):
For example, the pK a values of acetaldehyde and acetone are 16.7 and 19 respectively, while the pK a value of methane is extrapolated to be approximately 50.

Alanine

AlaL-alanineD-alanine
In a Strecker reaction, acetaldehyde condenses with cyanide and ammonia to give, after hydrolysis, the amino acid alanine.
Alanine was first synthesized in 1850 when Adolph Strecker combined acetaldehyde and ammonia with hydrogen cyanide.

1,1-Diethoxyethane

The product, CH 3 CH(OCH 2 CH 3 ) 2, is formally named 1,1-diethoxyethane but is commonly referred to as "acetal".
1,1-Diethoxyethane (acetaldehyde diethyl acetal) is a major flavoring component of distilled beverages, especially malt whisky and sherry.

Pentaerythritol

PE
In one of the more spectacular condensation reactions, three equivalents of formaldehyde add to MeCHO to give pentaerythritol, C(CH 2 OH) 4. Acetaldehyde is an important precursor to pyridine derivatives, pentaerythritol, and crotonaldehyde.
It may be prepared via a base-catalyzed poly-addition reaction between acetaldehyde and 3 equivalents of formaldehyde, followed by a Cannizzaro reaction with a fourth equivalent of formaldehyde to give the final product.

Functional group

groupfunctional groupsmoiety
This can cause confusion as "acetal" is more commonly used to describe compounds with the functional groups RCH(OR') 2 or RR'C(OR ) 2 rather than referring to this specific compound – in fact, 1,1-diethoxyethane is also described as the diethyl acetal of acetaldehyde.

Catalase

catalase testcatalase-negativeCAT
In the brain, the enzyme catalase is primarily responsible for oxidizing ethanol to acetaldehyde, and alcohol dehydrogenase plays a minor role.
Catalase can also catalyze the oxidation, by hydrogen peroxide, of various metabolites and toxins, including formaldehyde, formic acid, phenols, acetaldehyde and alcohols.

Metaldehyde

META fuel
Similarly condensation of four molecules of acetaldehyde give the cyclic molecule metaldehyde.
It is the cyclic tetramer of acetaldehyde.

Pyruvate decarboxylase

The last steps of alcoholic fermentation in bacteria, plants, and yeast involve the conversion of pyruvate into acetaldehyde and carbon dioxide by the enzyme pyruvate decarboxylase, followed by the conversion of acetaldehyde into ethanol.
Pyruvate decarboxylase is a homotetrameric enzyme that catalyses the decarboxylation of pyruvic acid to acetaldehyde and carbon dioxide in the cytoplasm of prokaryotes, and in the cytoplasm and mitochondria of eukaryotes.

Acetic acid

aceticglacial acetic acidacetate
In the liver, the enzyme alcohol dehydrogenase oxidizes ethanol into acetaldehyde, which is then further oxidized into harmless acetic acid by acetaldehyde dehydrogenase.
Prior to the commercialization of the Monsanto process, most acetic acid was produced by oxidation of acetaldehyde.

Vinyl acetate

Vinyl acetate monomeracetic acid ethenyl ester
Acetic anhydride reacts with acetaldehyde to give ethylidene diacetate, a precursor to vinyl acetate, which is used to produce polyvinyl acetate.
Since vinyl alcohol is highly unstable (with respect to acetaldehyde), the preparation of vinyl acetate is more complex than the synthesis of other acetate esters.

Strecker amino acid synthesis

Strecker synthesisStrecker reactionStecker reaction
In a Strecker reaction, acetaldehyde condenses with cyanide and ammonia to give, after hydrolysis, the amino acid alanine.
In the original Strecker reaction acetaldehyde, ammonia, and hydrogen cyanide combined to form after hydrolysis alanine.

Crotonaldehyde

2-butenalCrotonaldehyde, (E)-trans-butenal
Acetaldehyde is an important precursor to pyridine derivatives, pentaerythritol, and crotonaldehyde.
Crotonaldehyde is produced by the aldol condensation of acetaldehyde: