Aliphatic alcohols ethanol

The lower aliphatic alcohols (ethanol, isopropanol, 2-propanol, A-propanol, and 1-propanol) are widely used for skin antisepsis. In appropriate concentrations, these alcohols are bactericidal to most of the common pathogenic bacteria, but some rare species survive and can grow, especially since these alcohols are inactive against dried spores. 

Takahashi and co-workers exploited the reactivity of bound isonitriles with aliphatic alcohol (ethanol, propanol, butanol, pentanol) and amines by synthesizing various gold(l) carbene complexes The complexes existed... 

Probably the most widely used antiseptics are the lower aliphatic alcohols, ethanol and isopropanol. Less frequently used is N-propanol (i-propanol), although a combination with isopropanol is well known (Sterili-um). The bactericidal activity of the aliphatic alcohols increases with their molecular weight. Alcohols are considered less irritating than aldehydes. The irritancy of an alcohol compound decreases as the molecular size of the compound increases (Adams 1986). 

Such materials are soluble in the lower aliphatic alcohols, e.g.ethanol, and in phenols. They also absorb up to 21 % of moisture when immersed in water. If this material is heated with 2% citric acid at elevated temperatures, typically for 20 minutes at 120°C, cross-linking will take place Figure 18.20). 

Under microwave irradiation and applying MCM-41-immobilized nano-iron oxide higher activity is observed [148]. In this case also, primary aliphatic alcohols could be oxidized. The TON for the selective oxidation of 1-octanol to 1-octanal reached to 46 with 99% selectivity. Hou and coworkers reported in 2006 an iron coordination polymer [Fe(fcz)2Cl2]-2CH30H with fez = l-(2,4-difluorophenyl)-l,l-bis[(l//-l,2,4-triazol-l-yl)methyl]ethanol which catalyzed the oxidation of benzyl alcohol to benzaldehyde with hydrogen peroxide as oxidant in 87% yield and up to 100% selectivity [149]. An alternative approach is based on the use of heteropoly acids, whereby the incorporation of vanadium and iron into a molybdo-phosphoric acid catalyst led to high yields for the oxidation of various alcohols (up to 94%) with molecular oxygen [150]. 

Albano, E., Tomasi, A., Persson, J.O., Terelius, Y., Goria-Gatti, L., Ingelman-Sundberg, M. and Dianzani, M.U. (1991). Role of ethanol inducible cytochrome P-450 (P450IIE1) in catalysing the free radical activation of aliphatic alcohols. Biochem. Pharmacol. 41, 1895-1902. 

Rastogi, R. P. et al., Amer. Inst. Aero. Astronaut. J., 1966, 4, 1083-1085 Ignition delays were determined for contact of various aliphatic alcohols with mixtures of disulfuric acid (d, 1.9) and red finning nitric acid (d, 1.5). With ethanol, a minimum of 30 wt% of disulfuric acid was required for ignition. 

Hentz and Kenney-Wallace (1974) obtained the evolution of es yield in some common alcohols by comparison with the corresponding yield of ehand extrapolated the results to 30 ps. The picosecond data for the alcohols were obtained from the work of Wolff et al (1973) and Wallace and Walker (1972) the nanosecond work was in substantial agreement with Baxendale and Wardman (1971). The evolution of the es yields in the common alcohols shows considerable decay from the picosecond to nanosecond regime and a comparable decay from the nanosecond to microsecond time scales. However, the microsecond yields are also probably somewhat larger than previously reported, especially for methanol and ethanol (see Dorfman, 1965). In agreement with this, Lam and Hunt (1974) report es yields in aliphatic alcohols at -100 ps to be greater than 3. Nevertheless, there is room for neutralization of the dry electron in the presolvated state. 

Alcohol(s), 10 488. See also C12 alcohol Detergent range alcohols Ethanol Fuel alcohol Higher aliphatic alcohols Plasticizer range alcohols Polyhydric alcohols... 

The ALDs are a subset of the superfamily of medium-chain dehydrogenases/reductases (MDR). They are widely distributed, cytosolic, zinc-containing enzymes that utilize the pyridine nucleotide [NAD(P)+] as the catalytic cofactor to reversibly catalyze the oxidation of alcohols to aldehydes in a variety of substrates. Both endobiotic and xenobiotic alcohols can serve as substrates. Examples include (72) ethanol, retinol, other aliphatic alcohols, lipid peroxidation products, and hydroxysteroids (73). 

The LIF spectral shifts Av and the fluorescence lifetimes t concerning the complexes between F/j = (R)- or F = (5)-2-naphthyl-l-ethanol and a variety of primary and secondary aliphatic alcohols and terpenes (M) are hsted in Table 1.102.329,330... 

The use of ISEs in non-aqueous media(for a survey see [125,128]) is limited to electrodes with solid or glassy membranes. Even here there are further limitations connected with membrane material dissolution as a result of complexation by the solvent and damage to the membrane matrix or to the cement between the membrane and the electrode body. Silver halide electrodes have been used in methanol, ethanol, n-propanol, /so-propanol and other aliphatic alcohols, dimethylformamide, acetic acid and mixtures with water [40, 81, 121, 128]. The slope of the ISE potential dependence on the logarithm of the activity decreases with decreasing dielectric constant of the medium. With the fluoride ISE, the theoretical slope was found in ethanol-water mixtures [95] and in dimethylsulphoxide [23], and with PbS ISE in alcohols, their mixtures with water, dioxan and dimethylsulphoxide [134]. The standard Gibbs energies for the transfer of ions from water into these media were also determined [27, 30] using ISEs in non-aqueous media. 

Because of the problems encountered with the water system, the use of aliphatic alcohols, ie.g., methanol, ethanol, and isopropanol, as modifiers of the adsorption strength has been recommended (44. 45. 50. 51). Usually, between 0.01 and 0.5% (v/v) alcohol is added to the eluent. As an example, the k values for the benzyl alcohols on a silica column are in the same range when eluted with dichloromethane containing either 0.1% water (50% water-saturated) or 0.15% methanol or 0.3% isopropanol (45). The preparation and preservation of these alcohol-eluent mixtures is accompanied by problems similar to those discussed with water-modified eluents. Also, column equilibration is slow (44). The efficiency of columns operated with alcohol-modified eluents is generally lower than that of water-modulated eluent system. At some alcohol concentrations, distorted peaks with tailing or frontal asymmetry have been observed 44), but olhei workers using another silica could not verify this observa tion (61). 

There are thermochemical data for only one nonmethyl aliphatic hydroxylamine, N,N-diethylhydroxylamine . The enthalpy of formation difference between it and A-methyl-hydroxylamine is 71.6 kJ mol . This is very nearly the same as the difference of 79.7 kJ mol between the corresponding primary and secondary alcohols, ethanol and 3-pen-tanol, where the N of the hydroxylamine is replaced by a CH. Thus, the formal reaction enthalpy of equation 3 is only 8.1 kJmol . 

The adsorption of various aliphatic alcohols from benzene solutions onto silicic acid surfaces has been studied.t The experimental isotherms have an appearance consistent with the Langmuir isotherm. Both the initial slopes of an n/w versus c plot and the saturation value of n/w decrease in the order methanol > ethanol > propanol > butanol. Discuss this order in terms of the molecular structure of the alcohols and the physical significence of the initial slope and the saturation intercept. Which of these two quantities would you expect to be most sensitive to the structure of the adsorbed alcohol molecules Explain. 

The result of the reaction of sulfur tetrafluoride with alcohols strongly depends on the structure of the alcohol. Simple aliphatic alcohols, such as methanol, ethanol and propan-2-ol, give alkyl ethers as the main product with only small amounts of fluoroalkanes.41 42 Yields of fluorinated products increase with increasing acidity of the hydroxy group and, in general, the reaction is only synthetically useful with alcohols equally or more acidic than tropolone (p K, = 6.42). 

We therefore studied the effect of temperature and of concentration on the position of the hydroxyl peak in simple alcohols (methanol, ethanol, etc.) in the pure state, and in carbon tetrachloride or chloroform solutions. Some of the results of this work have already been reported [1]. A plot of peak position against concentration gives curves such as that in Fig. la. Interpretation of this type of curve from the N.M.R. data alone is impossible. It is clear that several different species (monomer, dimer, polymers) are contributing their effect, but because of the averaging phenomenon only a single OH peak, representing the weighted mean of all these species, is observed. We have now used infrared spectral data to clarify the situation. A careful examination of the infrared spectrum of all normal aliphatic alcohols... 

In some cases, the effect of reactant structure may outweigh the influence of catalyst nature. This is seen by comparison with the dehydration of aliphatic secondary alcohols and substituted 2-phenylethanols on four different oxide catalysts (Table 4). With aliphatic alcohols, the slope of the Taft correlation depended on the nature of the catalyst (A1203 + NaOH 1.2, Zr02 0.3, Ti02—0.8, Si02—2.8 [55]) whereas for 2-phenyl-ethanols, the slope of the corresponding Hammett correlation had practically the same value (from —2.1 to —2.4) for all catalysts of this series [95]. The resonance stabilisation of an intermediate with a positive charge on Ca clearly predominates over other influences. 

Few examples have been described of nucleophilic cleavage of carbonate- or carbamate-linked alcohols from insoluble supports. A serine-based linker for phenols releases the phenol upon fluoride-induced intramolecular nucleophilic cleavage of an aryl carbamate (Entry 2, Table 3.36). A linker for oligonucleotides has been described, in which the carbohydrate is bound as a carbonate to resin-bound 2-(2-nitrophen-yl)ethanol, and which is cleaved by base-induced 3-elimination (Entry 3, Table 3.36). Trichloroethyl carbonates, which are susceptible to cleavage by reducing agents such as zinc or phosphines, have been successfully used to link aliphatic alcohols to silica gel (Entry 4, Table 3.36). These carbonates can also be cleaved by acidolysis (Table 3.22). 

Phenols attached to insoluble supports can be etherified either by treatment with alkyl halides and a base (Williamson ether synthesis) or by treatment with primary or secondary aliphatic alcohols, a phosphine, and an oxidant (typically DEAD Mitsu-nobu reaction). The second methodology is generally preferred, because more alcohols than alkyl halides are commercially available, and because Mitsunobu etherifications proceed quickly at room temperature with high chemoselectivity, as illustrated by Entry 3 in Table 7.11. Thus, neither amines nor C,H-acidic compounds are usually alkylated under Mitsunobu conditions as efficiently as phenols. The reaction proceeds smoothly with both electron-rich and electron-poor phenols. Both primary and secondary aliphatic alcohols can be used to O-alkylate phenols, but variable results have been reported with 2-(Boc-amino)ethanols [146,147]. 

Alternatively, alkyl aryl ethers can be prepared from support-bound aliphatic alcohols by Mitsunobu etherification with phenols (Table 7.13). In this variant of the Mit-sunobu reaction, the presence of residual methanol or ethanol is less critical than in the etherification of support-bound phenols, because no dialkyl ethers can be generated by the Mitsunobu reaction. For this reason, good results will also be obtained if the reaction mixture is allowed to warm upon mixing DEAD and the phosphine. Both triphenyl- and tributylphosphine can be used as the phosphine component. Tributyl-phosphine is a liquid and generally does not give rise to insoluble precipitates. This reagent must, however, be handled with care because it readily ignites in air when absorbed on paper. 

Monohydric aliphatic alcohols having no strong electron-withdrawing substituent to facilitate ionization of the hydroxyl group are extremely weak acids in either aqueous or alcoholic media. The dissociation constant in aqueous solution at 25°C for methanol (4) is 2.9 X 10"16, for ethanol (4) and possibly other primary and secondary alkyl alcohols, <—1 X 10"16. In alcoholic media ionization constants may be 1/10-1/100 as large as those in aqueous media (22). 

Commercial crude lecithin is a hrown to light yellow fatly substance with a liquid to plastic consistency. Its density is 0.97 g/niL (liquid) and 0.5 g/mL (granule). The color is dependent on its origin, process conditions, and whether it is unbleached, bleached, or Altered. Its consistency is determined chiefly by its oil. free fatty acid, and moisture content. Properly refined lecithin has practically no odor and has a bland taste. It is soluble in aliphatic and aromatic hydrocarbons, including the halogenated hydrocarbons however, it is only partially soluble in aliphatic alcohols. Pure phosphatidylcholine is soluble in ethanol,... 

Appleyard (64) noted that addition of ethanol to incubation mixtures of sodium phenolphthalein diphosphate with prostatic extract increased the rate of free phenolphthalein formation. Phosphate ion failed to show a comparable increase, and this discrepancy was attributed to transphosphorylation. Phosphoryl transfer may be effected by prostatic phosphatase to acceptors other than solvent (65-67). Nigam and Fishman (25) studied phosphoryl transfer under conditions of 60-80% transfer to an acceptor. In the case of 1,4-butanediol, the optimal concentration was 0.8 M. In this experiment, water molecules outnumbered acceptor molecules by 55/0.8 or 70-fold. In spite of this, transfer far exceeded hydrolysis. Phosphoryl transfer to aliphatic alcohols can be easily measured when phosphates are used as donor compounds. The difference between alcohol formation from the substrate and phosphate ion production is a measure of the transfer reaction. Table IX (25) shows that four different substrates can transfer phosphoryl to butanediol with high efficiency. Table X (25) shows that aliphatic alcohols are good acceptors... 

Most of the other products found in irradiated meat volatiles except those containing sulfur or aromatic rings may also be accounted for by mechanisms associated with alkyl free radical formation in the fat. Oxygenated compounds are far less abundant than hydrocarbons, but appreciable amounts of a homologous series of n-aliphatic alcohols up to hexanol are found. Of these, only ethanol is detected in the unirradiated controls. Since the water content of meat averages nearly 60%, the formation of alcohols may be thought to occur by reaction of the alkyl free radical with water. Such a mechanism is supported by the fact that only traces of alcohols are found in irradiated dry butterfat and were undetected in irradiated triglycerides or methyl esters of fatty acids. 

The oxidation of primary aliphatic alcohols by l w(2,2,-bipyridyl)copper(ll) permanganate (BBCP) in aqueous acetic acid leads to the formation of the corresponding aldehydes446. The oxidation of [l,l-2H2]ethanol exhibited446 a kn/kn of 4.50. The formation constants for BBCP-alcohol complexes and the rates of their decomposition have been evaluated. Aliphatic aldehydes are oxidized by pyridinium hydrobromide... 

Gessner, P. K. Method for the assay of ethanol and other aliphatic alcohols applicable to tissue homogenates and possessing a sensitivity of 1 pg/ml. Anal. Biochem., 1970,... 

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