Methyl tert-butyl-ether

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... 

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... 

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. ... 

Attention has been given to possible adverse effects of incorporating tert-butyl methyl ether into antomobile fuels. tert-Butyl formate is an established product of photolysis, and it has been shown that photolysis in the presence of NO can produce the relatively stable tert-butoxyformyl peroxynitrate. This has a stability comparable to that of peroxy-acetyl nitrate, and may therefore increase the potential for disseminating NO (Kirchner et al. 1997). 

Reaction protocol 0.9 M 1-pentene, 0.18 M hydrogen peroxide (30%) and 0.2 M tert.-butyl methyl ether were dissolved in methanol [30], This mixture was passed over the catalyst at a rate of 30-120 pi h . Reaction was carried out at room temperature. The product mixture was collected in an ice bath. 

Dichloromethane, petroleum ether, diethyl ether, tert-butyl methyl ether, ethyl acetate... 

The mixture was transferred into a separating funnel. The aqueous phase was separated and extracted with tert-butyl methyl ether (2 x 20 mL). The brown combined organic layers were filtered through a pad of Celite , and then washed with water (2 x 40 mL) and with brine (2 x 40 mL), dried over sodium sulfate, filtered and concentrated under reduced pressure, giving a brown oil (700 mg). 

Scheme 1.34 Lipase resolution of a key intermediate in the synthetic route to an androgen receptor antagonist. TBME tert-butyl methyl ether...

The procedure is very easy to reproduce and to scale up. Bioconversion products can be easily isolated by evaporation of the extraction solvent (e.g. tert-butyl methyl ether). Table 12.4 summarizes the product concentrations, molecular conversion yields and enantioselectivities obtained during linalool biotransformation with C. cassiicola DSM 62475. 

The lipase-catalyzed resolutions usually are performed with racemic secondary alcohols in the presence of an acyl donor in hydrophobic organic solvents such as toluene and tert-butyl methyl ether (Scheme 1.3). In case the enzyme is highly enantioselective E = 200 or greater), the resolution reaction in general is stopped at nearly 50% conversion to obtain both unreacted enantiomers and acylated enantiomers in enantiomerically enriched forms. With a moderately enantioselective enzyme E = 20-50), the reaction carries to well over 50% conversion to get unreacted enantiomer of high optical purity at the cost of acylated enantiomer of lower optical purity. The enantioselectivity of lipase is largely dependent on the structure of substrate as formulated by Kazlauskas [6] most lipases show... 

Figure 3. Solubility data of neohexane (NH), methylcyclohexane (MCH), and tert-butyl methyl ether (MTBE) in water. The upper figure is the vapor-liquid-liquid equilibria at 275.5K and the lower figure is the liquid-liquid equilibria at atmospheric pressure. (Reprinted from Fluid Phase Equilibria (Susilo et al., 2005), Copy right (2005) with permission from Elsevier).

Susilo, R. Lee, J.D. Englezos, P. (2005). Liquid-liquid equilibrium data of water with neohexane, methylcyclohexane, tert-butyl methyl ether, n-heptane and vapor-liquid-liquid equilibrium with methane. Fluid Phase Equilibria, 231, 20-26. 

The mode and extent of asymmetric induction strongly depends on the solvent used in tert-butyl methyl ether with an optimum temperature of 0°C mostly e-attack occurred (Method A), whereas in THF or THF/HMPA Si-attack is observed (Method B). 

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