What is the reaction mechanism of ethylene oxide with alcohol? Oxidation of alcohols

The reaction mechanism of ethylene oxide and alcohol is divided into two types: acid catalysis and alkali catalysis.

The reaction mechanism catalyzed by acid is that the oxygen combination of Lewis acid and ethylene oxide makes the carbon more positively charged, which is conducive to the attack of alcohol hydroxyl groups. The principle of alkali catalysis is that the base takes the proton on the hydroxyl group of the alcohol, making the alcohol called potassium alkoxide, thus making the oxygen a negative ion, which makes it easier to attack the carbon ions of the positively charged ethylene oxide, thus making the ethylene oxide ring open.

Ethylene oxide and alcohol, using lewis acid such as boron trifluoride as a catalyst, can produce small molecule alcohol ether products. Lewis acid and ethylene oxide complex, making ethylene oxide easier to open the ring. Acid catalysis is generally used to produce products with a low degree of polymerization.

Ethylene oxide and alcohol, using potassium hydroxide, potassium alkyl and other alkalis as catalysts, can be polymerized to form products containing long chains of polyethylene glycol, such as nonionic surfactants, hydrophilic polyethers, etc.

Ethylene oxide. The reaction mechanism with alcohol, 2113 is divided into two 5261 kinds of acid catalysis and alkali catalysis.

Oxyethylene and alcohol, using 4102 with boron trifluoride and other Lewis acids as catalysts, can produce small molecule 1653 alcohol ether products. Lewis acid and ethylene oxide complex, making ethylene oxide easier to open the ring. Acid catalysis is generally used to produce products with a low degree of polymerization.

Oxyethylene and alcohol, using potassium hydroxide.

Bases such as potassium alkyl act as catalysts and can polymerize to form polyethylene glycol containing long chains.

products such as nonionic surfactants, hydrophilic polyethers, etc.

No matter how the bond is broken in the reaction between alcohol and ethylene oxide, the product is the same, and the reaction mechanism can be easily obtained by designing isotope tracing, such as the O in alcohol uses O-18, and then according to the position of O-18 in the product, it is easy to know the mechanism.

ro-18h

ch2)2o

ro-18-ch2ch2oh

Breaking H mechanism. ro-18h

ch2)2o

ro-ch2ch2o-18h

Breaking OH mechanism.

Personally, I am optimistic about the former for the following reasons: (1) the polarity of O-H is large, and (2) there may be a steric hindrance on R.

1.Primary alcohols are oxidized to form aldehydes.

2.Secondary alcohols are oxidized to form ketones.

3.Tertiary alcohols are not easily oxidized.

There are two conditions for alcohol-catalyzed oxidation:

1. Transition metals such as Cu or Ag are used as catalysts and heated;

2. The carbon atom attached to the hydroxyl group is the hydrogen atom on the carbon atom.

Alcohol oxidation products are determined by the type of carbon atom to which the hydroxyl group is attached.

Alcohols, a large group of organic compounds, are compounds formed by the substitution of hydrogen atoms in the side chains of aliphatic, alicyclic or aromatic hydrocarbons by hydroxyl groups.

Alcohols are affected by hydroxyl groups and have intermolecular hydrogen bonds, and in water there are also hydrogen bonds between alcohol molecules and water molecules. Therefore, their physical properties are quite different from the corresponding hydrocarbons. It is mainly manifested in the relatively high melting and boiling point, and has a certain solubility in water.

1. The essence of alcohol catalytic oxidation is: dehydrogenation, that is, the combination of the hydroxyl group of alcohol and the hydrogen of the C atom connected to the hydroxyl group of the alcohol with the O atom of oxygen to remove h to form water.

2. Therefore, if there are 2 or 3 H atoms attached to the C atom with an alcohol hydroxyl group, then this alcohol catalyzes oxidation to form aldehydes.

3. The C atom bonded to the alcohol hydroxyl group has an H.

4. The product of alcohol catalytic oxidation is that the C atom of ketone linked to the alcohol hydroxyl group has no H atom, and this alcohol cannot be catalyzed, for example, CH3CH2OH ==CH3CH3(CH3) 2CHOH ==CH3COCH3(CH3)3C OH alcohol will not undergo catalytic oxidation.

Oxidation of alcohols

It refers to the carbon atom where the alcohol hydroxyl group is located under the action of Cu or Ag as a catalyst.

There must be hydrogen atoms on it.

During the reaction, the hydrogen atom on the alcohol hydroxyl group and any hydrogen atom on the carbon atom where the alcohol hydroxyl group is located break the bond, and the oxygen atom becomes double-built; If there is only one hydrogen on the carbon atom where the alcohol hydroxyl group is located, then the hydrogen and the hydrogen atom of the alcohol hydroxyl group break the bond and form a ketone.

If there is no hydrogen on the carbon atom where the hydroxyl group of the alcohol is located, then the reaction cannot take place; The reaction products are divided according to the type of alcohol participating in the reaction

1. Primary alcohols are oxidized to form aldehydes.

2. Secondary alcohol oxidizes to form ketones.

3. Tertiary alcohol is not easy to be oxidized.

When it reacts with alcohol, ethylene oxide breaks off and forms an ether with alcohol, which is a free radical reaction.

1. React with active metals or strong bases to form alkyrites.

2. It is easy to react with hydrogen halide to form halogenated hydrocarbons.

and water. 3. Interact with inorganic oxygenated acids and organic acids to form esters by intermolecular dehydration.

4. Under certain conditions, alcohol can undergo dehydration reaction: (1) dehydration into olefins in the molecular round bicha.

2) Intermolecular dehydration into ethers.

5. Oxidation and dehydrogenation: primary alcohols are oxidized to form aldehydes, and aldehydes can continue to oxidize to form acids; Secondary alcohols are oxidized to form ketones. Under strong oxidation conditions, the C-C bond is broken to form small molecule oxidation products of orange eggplant.

The type of reaction in which ethylene glycol is produced to ethylene oxide is the elimination reaction.

1. The concept of elimination reaction:

The elimination of the hood coarse reaction, also known as the removal reaction, refers to an organic reaction in which the molecules of organic compounds and other substances react and lose some of the atoms or functional groups.

2. Elimination rules for elimination reactions:

1. Hoffman elimination.

Hoffmann eliminated the reaction of pyrolysis of quaternary ammonium base to form olefins, and mainly obtained the substituted ethylene with the fewest substituents on the double bond.

2. Thermal elimination reaction.

Typically carried out in the gas phase, ashwagandha is a single-molecule reaction that does not require acid or alkali catalysis.

3. Zaitsev elimination.

Zaitsev rule: dehalogenation of alkyl halides.

The type of reaction in which ethylene glycol is produced to ethylene oxide is the elimination reaction.

1. The concept of elimination reaction:

Elimination reaction, also known as removal reaction, refers to an organic reaction in which organic compound molecules and other substances react and lose part of their atoms or functional groups.

Second, the elimination of the reaction of the elimination of the dust shed rules:

1. Hoffman elimination.

Hoffman eliminated the reaction of pyrolysis of quaternary ammonium base to form olefins, and mainly obtained the substituted lead on the double bond and the least substituted ethylene.

2. Thermal elimination reaction. Trigger segment.

It is generally carried out in the gas phase and is a single-molecule reaction that does not require acid or base catalysis.

3. Zaitsev elimination.

Zaitsev rule: dehalogenation of alkyl halides.

Ethylene oxide reacts with water to form ethylene glycol.

Ethylene oxide reacts with water to form ethylene glycol, and the reaction equation is CH2CH2O + H2O = HOCH2CH2OH. Ethylene oxide is an organic compound, with the chemical formula C2H4O, which is a toxic carcinogen and was previously used to make fungicides; It is flammable and explosive, not easy to transport for long distances, has a strong regionality, and is widely used in washing, pharmaceutical, printing and dyeing industries.

Chemical properties of ethylene oxide:

Ethylene oxide, also known as ethylene oxide, is an important heterocyclic compound with potato dust dryer, the simplest ring ether, is a ternary ring formed by the connection of oxygen atoms and two adjacent carbon atoms, is a very active substance, its reaction is mainly carried out by the way of ring opening, and it will release extremely high heat during the reaction. If the reaction environment or reactor cannot dissipate heat in time, the vapor of ethylene oxide may decompose at higher temperatures. Ethylene oxide and compounds containing unstable hydrogen react to add to form a product containing hydroxyethyl group.