Methyl/-butyl ether

Water Less than 0.01% by Karl Fischer tltretlon Ultraviolet ebsorbance  

Substances darkened by sulfuric ecld Passes ACS test 

Infrared absorbance C-H and C-0 free. Shows no extraneous absorbance bands In the 3.1-3.6 end 5.6-6.0 micron ranges when observed In a 25 mm path length liquid cell. 

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Acid catalyzed addition of alcohols to alkenes is sometimes used Indeed before Its use as a gasoline additive was curtailed billions of pounds of tert butyl methyl ether (MTBE) was prepared by the reaction... 

Small amounts of tert butyl methyl ether increase the octane rating of gasoline Before environmental concerns placed limits on its use the demand for MTBE exceeded the supply... 

The susceptibihty of dialkyl peroxides to acids and bases depends on peroxide stmcture and the type and strength of the acid or base. In dilute aqueous sulfuric acid (<50%) di-Z fZ-butyl peroxide is resistant to reaction whereas in concentrated sulfuric acid this peroxide gradually forms polyisobutylene. In 50 wt % methanolic sulfuric acid, Z fZ-butyl methyl ether is produced in high yield (66). In acidic environments, unsymmetrical acychc alkyl aralkyl peroxides undergo carbon—oxygen fission, forming acychc alkyl hydroperoxides and aralkyl carbonium ions. The latter react with nucleophiles,... 

Because the Williamson synthesis is an S 2 reaction, it is subject to all the usual constraints, as discussed in Section 11.2. Primary halides and tosylates work best because competitive E2 elimination can occur with more hindered substrates. Unsymmetrical ethers should therefore be synthesized by reaction between the more hindered alkoxide partner and less hindered halide partner rather than vice versa. For example, terf-butyl methyl ether, a substance used in the 1990s as an octane booster in gasoline, is best prepared by reaction of tert-butoxide ion. with iodomethane rather than by reaction of methoxide ion with 2-chloro-2-methylpropane. 

Likewise, synthetic 2//-azepines isomerize to 3//-azepines in refluxing chloroform (2-3 h) or in tert-butyl methyl ether at room temperature.291 The isomers can be readily separated by chromatography on silica gel, as the more basic 2//-azepines30 have lower Rf values. In contrast, 7-butyl-2//-azepin-2-acetic acid (11), obtained by heating the tert-butyl ester 10 with iodotrimethylsilane, is stabilized by intramolecular hydrogen bonding and shows no tendency to rearrange to the 3//-isomer.291... 

In /cTf-butyl methyl ether, the optically active, bicyclic 2//-azepine 12 undergoes a suprafacial [1,5]-H shift to yield the isomeric, non-racemic 3/f-azepine 13.291... 

In rm-butyl methyl ether at 55 C the chiral 3//-azepine 13 is in equilibrium with the achiral 3//-isomer 27.291... 

To a solution of 5 mmol of 1,3-diphcnyl 3-[(S )-2-mcthoxymethyl-l-pyrrolidinyl]-2-propenyl[lithium in 10 mL of tort-butyl methyl ether (prepared according to Section D. 1.1.1.2.2.3.) at 0°C. 6.25 mmol of the aldehyde (and eventually 6.25 mmol of lithium halogenide in 27 mL of leri-butyl methyl ether) are added dropwise. Stirring is continued for 2 h and 0.39 g (5.0 mmol) of acetyl chloride are added. After 2 h stirring at r.t., 10 mL of the solvent, 50 mL of diethyl ether and 10 mL of 2 N aq hydrochloric acid are added and stirring is continued for 2 h at 20 C. The organic layer is extracted with three 20 mL-portions of water and the aqueous solutions are reextracted with diethyl ether. The combined aqueous solutions are dried over Na,S04, concentrated in vacuum and the residue distilled to yield a mixture of xyn- and on/i-ketones >90% ee, determined by H-NMR with Pr(hfc)3. 

The coupling photolysis Lewis acid is also sometimes effective in promoting a Diels-Alder reaction. Thus, cationic (R,S)-(ON)Ru-salen homochiral complex 71 catalyzed the Diels-Alder reaction between Danishefsky s diene and benzaldehyde when the reagents were exposed to direct sunlight through a window or to incandescent light in t-butyl methyl ether (TBME)[49] (Equation 4.8). The reaction in the dark was very slow and only 3 % ee was detected. 

Mobile phase Toluene — tert-butyl methyl ether — acetic acid (10%)... 

AA = amonium acetate. ACN = acetonitrile. BHT = butylated hydroxytoluene. CHjClj = dichloromethane. HEX = hexane. IS = internal standard. MeOH = methanol. RT = room temperature. TEA = triethylamine. TBME = tert-butyl methyl ether. THE = tetrahydrofuran. 

A biphasic solvent system composed of tert-butyl methyl ether, -butanol, acetonitrile, and water (2 2 1 5) acidified with triflnoroacetic acid has been applied to fractionate anthocyanins. The npper (organic) phase acts as the stationary phase and the lower (aqneons) as the mobile phase. HSCCC has been applied to obtain several anthocyanin fractions from wine, red cabbage, black cnrrants, chokeber-ries, " bilberries (Vaccinium myrtillus) acylated anthocyanins, and also isolate individnal anthocyanins from wine. ... 

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