Fert-Butyl ethyl ether

Chemists almost invariably use common names for low-molecular-weight ethers. For example, although ethoxyethane is the lUPAC name for CH3CH2OCH2CH3, it is rarely called that rather, it is called diethyl ether, ethyl ether, or even more commonly, simply ether. The abbreviation for fert-butyl methyl ether is MTBE, after the common name methyl fert-butyl ether (incorrectly alphabetized, as you will recognize). 

The nature of the initiation step, which may occur in a variety of ways, is not known in all cases. Commonly used ethers such as ethyl ether, isopropyl ether, tetrahydrofuran, and i)-dioxane are particulady prone to form explosive peroxides on prolonged storage and exposure to air and light (see Peroxides AND PEROXY COMPOUNDS, ORGANIC), and should contain antioxidants (qv) to prevent their build-up. One of the exceptions to the peroxide forming tendency of ethers is methyl fert-alkyl ethers such as methyl fert-butyl ether [1634-04-4] (MTBE) and fert-amyl methyl ether [994-05-8] (TAME). Both have shown htde tendency if any to form peroxides (2,8). 

Clofibrate Clofibrate, ethyl ether 2-(4-chloropheoxy)-M( -butyric acid (20.2.2), is synthesized by esterifying 2-(4-chlorophenoxy)-/yo-butyric acid (20.2.1) with ethyl alcohol. This is synthesized in a single-stage reaction from 4-chlorophenol, acetone, and chloroform in the presence of an alkali, evidently by initial formation of chlorethone-trichloro-tert-butyl alcohol, which under the reaction conditions is converted into (4-chlorophenoxy)trichloro-fert-butyl ether, and further hydrolyzed to the desired acid 20.2.1, which is further esterified with ethanol in the presence of inorganic acid [6-8]. 

Arce, A., Rodriguez, O., and Soto A., Purification of ethyl fert-butyl ether from its mixtures with ethanol by using an ionic liquid, Chem. Eng.., 115, 219, 2006. 

Other methods that have been less regularly used are the dehydration of alcohols with dimethyl sulfoxide to form symmetrical ethers, the photochemical transformation of benzylic chlorides with fert-butyl alcohol, or radical reactions of hcxafluoroacetone with alkanes, Mercury acetate promoted couplings of alcohols with vinyl acetate or vinyl ethyl ether to form vinyl... 

Krahenbuhl, M.A., Gmehling, J. (1994) Vapor pressure of methyl fert-butyl ether, ethyl fert-butyl ether, isopropyl tert-butyl ether, fert-amyl methyl ether, and ferf-amyl ethyl ether. J. Chem. Eng. Data 39, 759-762. 

Crown-6 (3.51 g, 13.28 mmol) was taken in 30 mL of THF, and the flask was cooled to -78 °C before addition of the phosphonate (2.90, 8.38 mmol) followed by dropwise addition of potassium hexamethyldisilazide (KHMDS 0.5 M in toluene, 16.0 mL, 8.38 mmol). After 10 min, the aldehyde (1.59 g, 6.68 mmol) was added in THF (10 mL). The reaction was quenched after 5 min with Nal ICO , solution. Extractive workup with methyl fert-butyl ether followed. The organic layer was then dried over MgSO4 and filtered. The solvent was evaporated in vacuo, and the crude product was chromatographed (hexane/EtOAc, 3 1) to give 1.73 g (85%) of the (Z)-a,p-unsaturated ethyl ester. 

The addition reaction of fert-butyl thioacetate-derived silyl ketene acetal produces the corresponding aldol adducts in 84% yield and up to 96% enantiomeric excess (Eq. 16). The enantioselectivity of the products was observed to be optimal with toluene as solvent the use of the more polar dichloromethane consistently produced adducts with 10-15% lower enantiomeric excess. The bulkier ferf-butylthioacetate-derived enol silane was found to lead to uniformly higher levels of enantioselectivity than the smaller S-ethyl thioketene acetal. This process is impressive in that it tolerates a wide range of aldehyde substrates for instance, the aldol addition reaction has been successfully conducted with aldehydes substituted with polar functionaUty such as N-Boc amides, chlorides, esters, and 0-benzyl ethers. A key feature of this system when compared to previously reported processes was the abiUty to achieve high levels of stereoselectivity at 0 °C, in contrast to other processes that commonly prescribe operating temperatures of -78 °C. 

Figure 5.13 Separation of phenolic antioxidants by thin-layer chromatography. Solvent benzene development distance 15 cm indicators (a) borate buffer (b) 0.1% 2,6-dichloro quinonechlorimide in methanol. 1 = hydroquinone monobenzyl ether 2 = 2,6-di-rerr-butyl-phenol 3 = 2,6-di-tert-butyl-4-methyl-phenol 4 = 2,6-di-tcrt-butyl-a-methoxy-4-methyl-phenol 5 = 2-a-methyl-cyclohexyl-4, 6-dimethyl-phenol 6 = butylated hydroxyanisole 7 = butylated hydroxy toluene 8 = 4,4"-bis (2,6-di-terf-butyl-phenol) 9 = 2,2"-methylene-bis (4-methyl-6-terf-butyl-phenol) 10 = 2,2"-methylene-bis (4-ethyl-6-fert-butyl-phenol) Reproduced from Kreiner and Warner, Journal of Chromatography [119]...

Methyl-seobutyi ether 65 Ethyl-fert-butyl ether 75 Methyl-r butyl ether... 

A mixture of 4-fert-butyl-2,6-dimethylphenol, ethyl vinyl ether, a reactive electron-ridi dienophile, and Ag-oxide stirred ca. 0.5 hr. until the dark color of the Ag-oxide turns to the light grey of reduced silver 2-ethoxy-6- er -butyl-8-methyl-diroman. Y 80%. F. e. s. D. A. Bolon, J. Org. Chem. 55, 3666 (1970). 

Others (ethyl, fert-butyl, neopentyl, allyl amines, sulfones, ether, amides) ZnEt2/H20 78... 

Figure lll-B-7. Arrhenius plot of the rate coefficient for the reaction of NO3 with Ce ethers (di-n-propyl ether, DnPE di-isopropyl ether, DiPE ethyl rerr-butyl ether, ETBE and fert-amyl methyl ether, TAME). 

An equimolar mixture of the crude amino alcohol and salicylaldehyde in toluene was heated under reflux for 2 h. Evaporation of the toluene followed by distillation of butyl fert-butylphenyl ether (bp 100 C/3 torr) gave the corresponding Schiff base as a yellow viscous residue. The yield was estimated to be 65% (LC) based on phenylalanine ethyl ester. A pure sample, [a]j3 -8.00 ° (c 1.00,chloroform), was isolated by column chromatography on silica gel [36]. 

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