CH3CHO+CH3CHO==CH3CH(OH)CH？ China hamster ovary (short for Chinese hamster ovary)
Aldehydes without α-hydrogen cannot undergo aldol condensation reaction, such as formaldehyde. Under alkaline conditions, autoxidation reaction (Conezaro reaction) occurs between aldehydes without α-hydrogen, and one molecule of alcohol and one molecule of acid: HCHO+HCHO==CH3OH+HCOOH are generated.
Extended data:
Under the action of dilute alkali or dilute acid, two molecules of aldehyde can interact. The α-hydrogen in one aldehyde molecule is added to the aldehyde oxygen atom of another aldehyde molecule, and the rest is added to the aldehyde carbon atom to generate a β-hydroxyaldehyde molecule.
There is no α-hydrogen in formaldehyde molecule, so there is no addition reaction between two formaldehyde molecules. When formaldehyde and acetaldehyde are added, the α -hydrogen in acetaldehyde is added to formaldehyde aldehyde oxygen, and the rest is added to aldehyde carbon to obtain the following structure: H0-CH? -CH？ -CHO；
At room temperature, except formaldehyde is gas, aliphatic aldehydes with carbon atoms less than 12 in the molecule are liquid and higher aldehydes are solid; While aromatic aldehydes are liquid or solid. Lower aliphatic aldehydes have a strong pungent smell. Aldehydes with 9 carbon atoms in the molecule and 10 carbon atoms in the molecule have the fragrance of flowers and fruits, so they are often used in perfume industry.
Because of the polarity of carbonyl group, the boiling point of aldehyde is higher than that of hydrocarbons and ethers with similar molecular weight. However, because hydrogen bonds cannot be formed between carbonyl molecules, the boiling point is lower than that of the corresponding alcohol.
Because the carbonyl group of aldehyde can form hydrogen bond with hydrogen in water, lower aldehyde can be dissolved in water; However, aromatic aldehydes are usually insoluble in water.
Aldehydes can be divided into aliphatic aldehydes, ester cyclic aldehydes, aromatic aldehydes and terpene (Ti) olefins. Aliphatic aldehyde refers to an aldehyde in which carbon atoms in the molecule are connected into a chain, and this chain is open. Alicyclic aldehyde refers to the carbon atoms in the molecule connected to form a closed carbon ring. The carbonyl group of aromatic aldehyde is directly attached to the aromatic ring. Terpenaldehyde is a branch of terpenoids.
1. Aliphatic compounds refer to carbon chains formed by the combination of carbon atoms in molecules, not cyclic. Fatty aldehyde is a kind of aliphatic compound.
Common acyclic fatty aldehydes are octanal, nonanal, decanal, undecal, laural (dodecanal), tridecane aldehyde, myristic aldehyde (tetraldehyde), methylhexylacetaldehyde, methyloctyl acetaldehyde, methylnonyl acetaldehyde, trimethylhexanal, tetramethylhexanal, trans -2- hexenal, 2- nonenal and trans -4- decenal.
2. alicyclic compounds can be regarded as those obtained by linking and closing open-chain compounds into rings. Alicyclic aldehyde is a kind of alicyclic compound.
Common alicyclic aldehydes are: privet aldehyde, ivy aldehyde, isocyclic citral, citral, methyl citral, neolily aldehyde and so on.
3. The carbonyl group of aromatic aldehydes is directly attached to the aromatic ring, and such aldehydes can be regarded as derivatives of benzene.
Common aromatic aldehydes are benzaldehyde, phenylacetaldehyde, phenylpropanal, cinnamaldehyde, lily aldehyde, vanillin, ethyl vanillin and so on.
4. Terpenaldehyde refers to a classification of terpenoids, and terpenoids refer to derivatives with the general formula (C5H8)n and its oxygen content and different saturation.
Common terpene aldehydes are: citral, citronellal, hydroxycitronellal, perillal, trimethyl heptene aldehyde, etc.
References:
Baidu encyclopedia-aldehyde