Dimethoxymethane
Encyclopedia
Dimethoxymethane, also called methylal, is a clear colorless flammable liquid with a low boiling point, low viscosity
and an excellent dissolving power. It has a chloroform
-like odor and a pungent taste. It is the dimethyl acetal
of formaldehyde
. Dimethoxymethane is soluble in three parts water and miscible with most common organic solvents.
It can be manufactured by oxidation of methanol
or by the reaction of formaldehyde with methanol. In aqueous acid, it is hydrolyzed
back to formaldehyde and methanol.
It is primarily used as a solvent and in the manufacture of perfumes, resins, adhesives, paint strippers and protective coatings.
Another useful application of dimethoxymethane is to protect alcohols with a MOM ether in organic synthesis. This can be done using phosphorus pentoxide
in dry dichloromethane
or chloroform
. This is a preferred method to using MOM-Cl. The MOM-ether can be removed using methanol and pToluene Sulphonic Acid as an alternative to aqueous acid.
Due to the anomeric effect
, dimethoxymethane has a preference toward the gauche conformation
around the C–O bonds, instead of the anti conformation. Since it is one of the smallest molecules exhibiting this effect, which has great interest in carbohydrate chemistry, dimethoxymethane is often used for theoretical studies of the anomeric effect.
Viscosity
Viscosity is a measure of the resistance of a fluid which is being deformed by either shear or tensile stress. In everyday terms , viscosity is "thickness" or "internal friction". Thus, water is "thin", having a lower viscosity, while honey is "thick", having a higher viscosity...
and an excellent dissolving power. It has a chloroform
Chloroform
Chloroform is an organic compound with formula CHCl3. It is one of the four chloromethanes. The colorless, sweet-smelling, dense liquid is a trihalomethane, and is considered somewhat hazardous...
-like odor and a pungent taste. It is the dimethyl acetal
Acetal
An acetal is a molecule with two single-bonded oxygen atoms attached to the same carbon atom.Traditional usages distinguish ketals from acetals...
of formaldehyde
Formaldehyde
Formaldehyde is an organic compound with the formula CH2O. It is the simplest aldehyde, hence its systematic name methanal.Formaldehyde is a colorless gas with a characteristic pungent odor. It is an important precursor to many other chemical compounds, especially for polymers...
. Dimethoxymethane is soluble in three parts water and miscible with most common organic solvents.
It can be manufactured by oxidation of methanol
Methanol
Methanol, also known as methyl alcohol, wood alcohol, wood naphtha or wood spirits, is a chemical with the formula CH3OH . It is the simplest alcohol, and is a light, volatile, colorless, flammable liquid with a distinctive odor very similar to, but slightly sweeter than, ethanol...
or by the reaction of formaldehyde with methanol. In aqueous acid, it is hydrolyzed
Hydrolysis
Hydrolysis is a chemical reaction during which molecules of water are split into hydrogen cations and hydroxide anions in the process of a chemical mechanism. It is the type of reaction that is used to break down certain polymers, especially those made by condensation polymerization...
back to formaldehyde and methanol.
It is primarily used as a solvent and in the manufacture of perfumes, resins, adhesives, paint strippers and protective coatings.
Another useful application of dimethoxymethane is to protect alcohols with a MOM ether in organic synthesis. This can be done using phosphorus pentoxide
Phosphorus pentoxide
Phosphorus pentoxide is a chemical compound with molecular formula P4O10 . This white crystalline solid is the anhydride of phosphoric acid. It is a powerful desiccant.-Structure:...
in dry dichloromethane
Dichloromethane
Dichloromethane is an organic compound with the formula CH2Cl2. This colorless, volatile liquid with a moderately sweet aroma is widely used as a solvent. Although it is not miscible with water, it is miscible with many organic solvents...
or chloroform
Chloroform
Chloroform is an organic compound with formula CHCl3. It is one of the four chloromethanes. The colorless, sweet-smelling, dense liquid is a trihalomethane, and is considered somewhat hazardous...
. This is a preferred method to using MOM-Cl. The MOM-ether can be removed using methanol and pToluene Sulphonic Acid as an alternative to aqueous acid.
Due to the anomeric effect
Anomeric effect
In organic chemistry, the anomeric effect or Edward-Lemieux effect is a stereoelectronic effect that describes the tendency of heteroatomic substituents adjacent to a heteroatom within a cyclohexane ring to prefer the axial orientation instead of the less hindered equatorial orientation that would...
, dimethoxymethane has a preference toward the gauche conformation
Conformational isomerism
In chemistry, conformational isomerism is a form of stereoisomerism in which the isomers can be interconverted exclusively by rotations about formally single bonds...
around the C–O bonds, instead of the anti conformation. Since it is one of the smallest molecules exhibiting this effect, which has great interest in carbohydrate chemistry, dimethoxymethane is often used for theoretical studies of the anomeric effect.