1.2- Dimethoxyethane glyme

Ordinary ketones are generally much more difficult to cleave than trihalo ketones or p-diketones, because the carbanion intermediates in these cases are more stable than simple carbanions. However, nonenolizable ketones can be cleaved by treatment with a 10 3 mixture of t-BuOK—H2O in an aprotic solvent such as ether, dimethyl sulfoxide, 1,2-dimethoxyethane (glyme), and so on, or with sohd t-BuOK in the absence of a solvent. When the reaction is applied to monosubstituted diaryl ketones, that aryl group preferentially cleaves that comes off as the more stable carbanion, except that aryl groups substituted in the ortho position are more readily cleaved than otherwise because of the steric effect (relief of stain). In certain cases, cyclic ketones can be cleaved by base treatment, even if they are enolizable. " OS VI, 625. See also OS VH, 297. 

A similar desymmetrization of the dienyl ethers was accomplished using cationic rhodium(l)/BIPNOR complex. In this reaction, an oxygen-containing co-solvent was necessary, and the best result was obtained with a 3 1 mixture of toluene and 1,2-dimethoxyethane (glyme) (DME) (Equation (21)). 

Other ethers have been employed without comment as to their particular advantage. These include tetrahydrofuran,28 diisopropyl ether,80 dibutyl ether,4 61,76 bis(3-methylbutyl) ether81 and 1,2-dimethoxyethane (glyme).82 If vacuum removal of a product with a higher boiling point from the reaction mixture is preferable, polyethers such as bis[2-(2-methoxyethoxy)ethyl] ether (tetraglyme)83 or bis[2-(2-butoxyethoxy)ethyl] ether (butyltetraglyme)70 are recommended. 

Solvent effects Birch reduction. 1,2-Dimethoxyethane (Glyme) and Dimethyl ether (see Naphthalene-Sodium), Dimethylformamide. Dimethyl sulfone. Dimethyl sulfoxide. Diphenyl sulfoxide. Ethylene glycol. N-EthylmorphoUne. Hexamethylphosphoric triamide. Methylal. Methylene chloride. Methyl ethyl ketone. N-Methyl-2-pyrrolidone. Nitrometbane. Nitrosyl chloride. Phenetole. Tetrahydrofurane. Tetramethylene sulfone. Tetramethylene sulfoxide. Triethanolamine. Triethyl phosphate. Trifluoroacetic acid,... 

Metallic sodium reacts with t-nitrobutane in 1,2-dimethoxyethane (glyme) to form a salt, [(CHslsClzNOa Na, which is hydrolyzed to the red liquid radical, stable to oxygen, water, and aqueous alkali. This is a useful radical scavenger, particularly for photolytic decompositions, since it has low absorption in the near ultraviolet. ... 

Dimethoxyethane (Glyme) fl, 267-268, before references]. In a systematic study of enolate anions, House10 selected this solvent because it will provide approximately 1 M concentrations of most enolate anions, it is relatively volatile and easily removed from products, it possesses no H-atoms sufficiently acidic to exchange with enolate anions, and it enhances the reactivity of anions by solvation. 

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