organic chemistry Organic chemistry is a subdiscipline within chemistry involving the science, scientific study of the structure, properties, and reactions of organic compounds and organic matter, organic materials, i.e., matter in its various forms that contain ...

, a methoxymethyl ether is a

functional group In organic chemistry, a functional group is any substituent or moiety (chemistry), moiety in a molecule that causes the molecule's characteristic chemical reactions. The same functional group will undergo the same or similar chemical reactions r ...

with the formula , abbreviated MOM. The group is usually derived from

chloromethyl methyl ether Chloromethyl methyl ether (CMME) is a compound with formula CH3OCH2Cl. A colorless liquid, it is a chloroalkyl ether. It is used as an alkylating agent. In organic synthesis, it is used for introducing the methoxymethyl ether (MOM) protecting ...

, a kind of chloroalkyl ether which is, like its congeners, often employed in organic synthesis to protect alcohols. Closely related to MOM ethers are methoxyethoxymethoxy (MEM) protecting groups, introduced using 2-methoxyethoxymethyl chloride. The MEM protecting groups are more easily installed and more easily removed.

Protection

Typically, the alcohol is protected by addition of the chloromethyl reagent followed by deprotonation with a non-nucleophilic base such as

N,N-diisopropylethylamine ''N'',''N''-Diisopropylethylamine, or Hünig's base, is an organic compound that is a tertiary amine. It is named after the German chemist . It is used in organic chemistry as a non-nucleophilic base. It is commonly abbreviated as DIPEA, DIEA, o ...

(DIPEA) in

dichloromethane Dichloromethane (DCM, methylene chloride, or methylene bichloride) is an organochlorine compound with the formula . This colorless, volatile liquid with a chloroform-like, sweet odor is widely used as a solvent. Although it is not miscible with ...

. Although not relevant to protecting groups, MOM groups are installed by reaction of chloromethyl ethers with methoxide and by the acid-catalyzed reaction of alcohols with

dimethoxymethane Dimethoxymethane, also called methylal, is a colorless flammable liquid with a low boiling point, low viscosity and excellent dissolving power. It has a chloroform-like odor and a pungent taste. It is the dimethyl acetal In organic chemis ...

Deprotection

The MOM and the MEM protecting groups can be cleaved with a range of Lewis and Bronsted acids.

Safety

Chloromethyl methyl ether Chloromethyl methyl ether (CMME) is a compound with formula CH3OCH2Cl. A colorless liquid, it is a chloroalkyl ether. It is used as an alkylating agent. In organic synthesis, it is used for introducing the methoxymethyl ether (MOM) protecting ...

and chloromethoxyethoxymethane, like other chloroalkyl ethers, are strong

alkylating agent Alkylation is a chemical reaction that entails transfer of an alkyl group. The alkyl group may be transferred as an alkyl carbocation, a free radical, a carbanion, or a carbene (or their equivalents). Alkylating agents are reagents for effecting ...

s with attendant dangers. These compounds are human

carcinogen A carcinogen () is any agent that promotes the development of cancer. Carcinogens can include synthetic chemicals, naturally occurring substances, physical agents such as ionizing and non-ionizing radiation, and biologic agents such as viruse ...

.Bis(chloromethyl) Ether and Technical-Grade Chloromethyl Methyl Ether CAS Nos. 542-88-1 and 107-30-2
''Report on carcinogens'', Eleventh edition

References

{{Reflist Ethers