Ethers, aliphatic, tert

Evans Edlund(Ref 1 3) reacted an aliphatic polyhydric ale with tert-butylene in the presence of a condensing agent(such as H2S04) and obtd the following ethers mono-tert-Butyletber of Ethylene Glycol (called Athylengylkol-mono-tert-butylather in Ger), (H3C)3.C.O.CH2.CH2OH, mw 118.17,... 

Good enantioselectivity was observed in the reaction of aromatic R -substituted silyl enol ethers and tert-alkyl R - and small alkyl R -disubstituted silyl enol ethers (Sch. 9). Interestingly, the absolute stereochemical course for aliphatic silyl enol ethers is the opposite of that for aromatic ethers. The (trimethylsilyl)ethyl group was easily removed without racemization by treatment with hydrogen fluoride-pyridine. 

Hydroperoxides in the presence of vanadium molybdenum, or titanium compounds give high yields of aliphatic tert. amine oxides from the corresponding amines and sulfones from thio-ethers or sulfoxides. 

Aliphatic and aromatic carboxamides, with the exception of p-nitrobenzamide, are dehydrated in this way in high yield. Acid-labile protective groups such as tetra-hydropyranyl and tert-butyldimethylsilyl ether and base-sensitive compounds are not attacked. A,A -Sulfinyldi-1,2,4-triazole, easily prepared from thionylchloride and triazole [THF, (C2H5)3N, 0 °C, 1 h] in 85-95% yield, was used without further purification. 

TABLE 8. Primary aliphatic organoUthiums Li—R by halogen/metal permutation between haloalkanes X—R and tert-butylUthium in diethyl ether at —75°C... 

Methyl tert-Butyl Ether MTBE Methyl Tertiary Butyl Ether under Noncyclic Aliphatic or Aromatic Ethers Molybdenum... 

Aliphatic amines have much less effect on the later reactions of the gas-phase oxidation of acetaldehyde and ethyl ether than if added at the start of reaction. There is no evidence that they catalyze decomposition of peroxides, but they appear to retard decomposition of peracetic acid. Amines have no marked effect on the rate of decomposition of tert-butyl peroxide and ethyl tert-butyl peroxide. The nature of products formed from the peroxides is not altered by the amine, but product distribution is changed. Rate constants at 153°C. for the reaction between methyl radicals and amines are calculated for a number of primary, secondary, and tertiary amines and are compared with the effectiveness of the amine as an inhibitor of gas-phase oxidation reactions. 

The present procedure is the best way of preparing aliphatic isocyanides boiling above ethyl isocyanide. It has been applied to the synthesis of the following isocyanides 6 isopropyl (38%), -butyl (61%), tert-butyl (68%), and benzyl (56%). In preparing isopropyl isocyanide or ferf-butyl isocyanide, the petroleum ether should be of boiling point 30-35°, as otherwise it is difficult to separate these low-boiling isocyanides in the indicated yield, and,... 

Both reactivity and selectivity decreased with increasing steric bulk of alkyl group on the vinyl ether (Et> -Pr> -Bu /-Bu), and tert-butyl vinyl ether was completely unreactive. The cycloaddition of ethyl vinyl ether with a wide variety of oc, 3-unsaturated aldehydes bearing aliphatic and aromatic P-substituents proceeded with high selectivity (>95% de, 89-98% ee). Only 5 mol% of catalyst were necessary except in the case of sterically more demanding substituents (R = i-Pr, Ar) that required 10 mol% of catalyst loading. Substitution could also be introduced in the a-position of the unsaturated aldehyde, and cycloadducts were obtained with similar high selectivities.26... 

Aliphatic alcohols and benzyl alcohol are oxidized by Ph3Bi(OOtBu)2 to the corresponding carbonyl compounds (Equation (141)).233 It has been suggested that the oxidation occurs via dehydrogenation of alcohols by phenyl or tert-butoxy radical. When treated with diethyl ether, Ph3Bi(OOtBu)2 oxidizes the methyl group to afford ethoxyacetic... 

The classical method for making tert-butyl esters involves mineral acid-catalysed addition of the carboxylic acid to isobutene but it is a rather harsh procedure for use in any but the most insensitive of substrates [Scheme 6.33].80-82 Moreover, the method is hazardous because a sealed apparatus is needed to prevent evaporation of the volatile isobutene. A simpler procedure [Scheme 6.34] involves use of tert-butyl alcohol in the presence of a heterogeneous acid catalyst — concentrated sulfuric acid dispersed on powdered anhydrous magnesium sulfate. 3 No interna] pressure is developed during the reaction and the method is successful for various aromatic, aliphatic, olefinic, heteroaromatic, and protected amino acids. Also primary and secondary alcohols can be converted into the corresponding /erf-butyl ethers using essentially the same procedure (with the exception of alcohols particularly prone to carbonium ion formation (e.g. p-... 

If these parameters are used for the construction of a diagram as shown in Figure 5.1, a solvent selectivity triangle is obtained which clearly shows the differences between the individual solvents with regard to their dipolar (re ), acidic (a) and basic (/3) properties.2 The largest differences in the elution pattern can be expected if solvents are chosen which are as far apart from each other as possible. Because mixtures of two solvents, A and B, are used in most cases, only such solvents can be chosen which are miscible with each other. The usual A solvent in normal-phase separations is hexane, in reversed-phase separations it is water. Therefore the possible B solvents are limited in number. With regard to selectivity, it makes no real sense to try a normal-phase separation with diethyl ether as well as with tert, butyl methyl ether because all aliphatic ethers are located at the same spot in the selectivity triangle. Likewise it is not necessary to try several aliphatic alcohols for reversed-phase separations. 

ETHANOL (64-17-5) CjHjOH Flammable liquid. Forms explosive mixture with air [explosion limits in air (% by volume) 3.3 to 19 flash point 55°F/13°C 68°F/20°C (80%) 72°F/22°C (60%) 79°F/26°C autoignition temp 685°F/363°C Fire Rating 3], Reacts, possibly violently, with strong oxidizers, strong acids bases, strong peroxides acetic anhydride, acetyl bromide, acetyl chloride, aliphatic amines, bromine pentafluoride, calcium oxide (quicklime), cesium oxide, chloryl perchlorate, disulfiiryl difluoride, ethylene glycol methyl ether, iodine heptafluoride, isocyanates, nitrosyl perchlorate, perchlorates, platinum, platinum-black catalyst potassium-tert-butoxide, potassium, potassium oxide, potassium peroxide, potassium superoxide phosphorus (III) oxide, silver nitrate, silver oxide, sulfuric acid, oleum, sodium, sodium hydrazide, sodium peroxide, sulfinyl cyanamide, tetrachlorosilane, s-triazine-... 

Classification Tert. aliphatic alcohol Empirical CsHi20 Formula CH3CH2C(CH3)20H Properties Colorless clear volatile liq., char, camphoraceous odor, burning taste sol. in 8 parts water misc. with alcohol, ether, benzene, chloroform, glycerin, oils m.w. 88.15 sp.gr. 0.808 (20/4 C) vapor pressure 10 mm Hg (17.2 C) m.p. -9 C b.p. 100-103 C flash pt. (CC) 19 C ref. index 1.405... 

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