Simple Aliphatic Alcohols Research Articles

Direct enantiomer resolution of primary, secondary, and tertiary alcohols by gas chromatography on Chirasil-Val

Many enantiomeric pairs of alcohols (primary, secondary or tertiary) are resolved directly on persilylated glass capillary columns, coated with the chiral stationary phase L- or D-Chirasil-Val. Dependent on the chemical structure of the substrate, considerable resolution factors can be obtained, even with simple aliphatic alcohols. Thus, one strong attraction may be sufficient to produce significant chiral recognition. Enantiomeric purities of these alcohols can be determined with high accuracy and great ease.

Radiolysis of p-benzoquinone solutions

The γ-radiolysis of p-benzoquinone (Q) at different concentrations of H2SO4, Q, O2 and Cl− are p-hydroquinone (H2 Q), 2-hydroxy-p-benzoquinone (2-Q-OH) and H2O2. The effect of Cl− on yields is similar to its effect in deaerated solutions. The yields of H2Q and 2-Q-Oh are lower than in deaerated solutions. In the presence of simple aliphatic alcohols, a carbonyl compound is also measured in addition to those mentioned above. This system is found to be more complex than in deaerated solutions. Q and O2 were found to compete for the radical R1 R2 COH and good agreement was obtained between observed and reported rate coefficients of the reactions involved. There is some evidence that at lower pH, alcohol peroxy radicals are also able to undergo electron transfer with quinone.

Effect of alcohols on the thermal denaturation and aggregation of arachin at pH 3,6

AbstractThe effects of three simple aliphatic alcohols, viz., methanol, ethanol and 1‐propanol, on the thermal denaturation and protein‐protein interactions of arachin at pH 3,6 were studied by melting temperature, electrophoresis, UV difference and fluorescence spectral measurements. Alcohols increase the heat‐induced protein‐protein interactions as shown by gel melting temperature and electrophoretic measurements. UV difference and fluorescence spectral measurements revealed that the addition of alcohols to arachin, before and after heating and cooling, enhances its denaturation. The probable explanation for the promotive effect of alcohols on the thermal denaturation and aggregation of arachin is discussed.

Gas-phase NMR studies of alcohols. Intrinsic acidities

Abstract Gas-phase (≈100 Torr) 1H NMR spectra of eighteen simple aliphatic and unsaturated alcohols, four fluorinated alcohols, and two thiols were obtained at 148.6°C where hydrogen bonding has little effect on chemical shifts. For the methanol, ethanol, n-propanol, i-propanol, t-butanol, i- butanol, neopentanol, 2,2,2-trifluoroethanol and benzyl alcohol, the observed hydroxylic proton chemical shifts correlate with previously obtained relative gas-phase acidities from thermochemical analysis which employed equilibrium constants of proton transfer reactions measured via mass spectroscopic and ion cyclotron resonance techniques. The correlational dependence is 10.3(0.5) kcal/mol ppm with a correlation coefficient of 0.99. These results demonstrate that the trend of increasing acidity with increasing size of the alkyl substituent is also reflected in the neutral forms of the alcohols, indicating that the polarizability of the ionic forms is not the only determining factor in relative gas-phase acidities of alcohols. Although factors affecting the hydroxylic proton chemical shifts of the larger substituted and unsaturated alcohols are more complex, their observed 1H NMR spectra also reflect this trend. For methanol and ethanol observed gas-phase 1H chemical shifts are also compared with recent theoritical calculations. 3JHH coupling constants across CO bonds are ≈ 5.5 Hz, significantly smaller than typical 3JHH coupling across sp3 hybrid CC bonds.

Solvent effects on allosteric equilibria: stabilization of T and R conformations of Escherichia coli aspartate transcarbamylase by organic solvents.

The activity of Escherichia coli aspartate transcarbamylase (ATCase) is markedly influenced by the addition of organic solvents to the assay medium. The cosolvents tested, which include simple aliphatic alcohols, amides, and ureas, as well as acetone and dioxane, fall into two different classes: the most polar ones (formamide, acetamide, N-methylformamide, and urea) stimulate the enzyme activity for all concentrations tested. In contrast, solvents that are less polar than water inhibit the enzyme at low concentrations but stimulate it at higher concentrations. No comparable effects are observed in the case of the isolated catalytic subunits, a non-regulated form of ATCase. Extensive kinetic studies on ATCase and on two of its Michaelian derivatives, 2-thioU-ATCase and carbamylated ATCase, indicate that solvents modulate the same allosteric transition that is responsible for homotropic interactions between the catalytic sites. The stabilization of the R state of ATCase by comparatively high concentrations of cosolvents is reminiscent of similar findings made on hemoglobin and glycogen phosphorylase, suggesting a common underlying mechanism. Addition of organic cosolvents to water is known to reduce hydrophobic interactions, and we suggest that this effect may preferentially stabilize the more "relaxed" conformations of allosteric proteins, because they have a larger surface exposed to solvent [Chothia, C. (1974) Nature (London) 248, 338-339]. On the other hand, we suggest that the stabilization of the T state by low concentrations of all but the most polar cosolvents simply reflects stronger electrostatic interactions in this conformation.

Charge partitioning by zero-flux surfaces: The acidities and basicities of simple aliphatic alcohols and amines

The zero-flux surface criterion for the partitioning of the total molecular electron density is investigated in order to determine the sensitivity of the populations to basis set. Electron populations obtained from this criterion are used to rationalize the acidities and basicities of simple aliphatic alcohols and amines.

Slow multiphoton excitation as a probe of bimolecular and unimolecular reaction energetics. Multiphoton dissociation of proton-bound alcohol dimers

Proton bound dimers of simple aliphatic alcohols (R/sub 1/OH)H/sup +/(R/sub 2/OH) where R/sub 1/ = R/sub 2/ = CH/sub 3/, C/sub 2/H/sub 5/, i-C/sub 3/H/sub 7/, n-C/sub 3/H/sub 7/, s-C/sub 4/H/sub 9/, t-C/sub 4/H/sub 9/, and t-C/sub 5/H/sub 11/ are intermediates formed in gas phase reactions of the corresponding protonated alcohols with neutral alcohols. Products from the decomposition of these chemically activated species are compared with those obtained by slow multiphoton excitation. In addition, it is shown that isomeric ions are distinguished by formation of different sets of decomposition products. Also, we report the first observation of multiple sets of products arising from low-power infrared activation. This result is due to an exothermic isomerization in the transition state which makes accessible more than one reaction pathway. Use of infrared multiphoton excitation as a complementary technique to collisional activation of ions in mass spectrometric analysis of mixtures is discussed. For this study, ions are formed, stored, and detected by using techniques of ion cyclotron resonance (ICR) spectroscopy.

Dehydrogenation of Triterpenoid Alcohols in Alkali Melt. A Short Synthesis of the So-Called Jasminol

Abstract Alkali fusion is a venerable method1 for the dehydrogenation of simple aliphatic alcohols to give carboxylic acids (Dumas-Stass reaction), and has been used in isolated cases for ketone synthesis from secondary alcohols as well. We report here the results of a study on alkali fusion reactions of some representative triterpenoid alcohols, and show that unique and preparatively useful reactions take place. Our results are summarised in the Table2.

Inactivation of acetylcholinesterase by propanol and sodium dodecyl sulphate

Departure from first-order kinetics was observed for the inactivation of bovine erythrocyte and electric eel acetylcholinesterase (acetylcholine hydrolase, EC 3.1.1.7) by n- propanol . This was attributed to the presence of isoenzymes in the commercial preparations, although inactivation via a two-step process cannot be eliminated. The rate of inactivation of bovine erythrocyte enzyme by propanol or sodium dodecyl sulphate was decreased by the presence of added protein and increased by Triton X-100. The presence of a substrate (acetylthiocholine) decreased the rate of inactivation of bovine erythrocyte acetylcholinesterase by sodium dodecyl sulphate, but increased the rate of inactivation by propanol. Re-interpretation of earlier data on the inactivation and reversible inhibition of acetylcholinesterase by simple aliphatic alcohols indicated that they do not bind to hydrophobic regions of the active site.

Duality of pathways in the reaction of N-phenyltriazolinedione with alcohols

N-Phenyltriazolinedione (1) in benzene gives 1-alkoxycarbonyl-2-N-phenylcarbamoyl-4-phenyl-1,2,4-triazolidine-3,5-diones (2) as the major product with simple primary aliphatic alcohols, and a minor one with secondary alcohols which are mainly oxidized to the carbonyl compound; the oxidation can, however, be suppressed in favour of the formation of (2) by addition of pyridine.

The Radiolytic-chain Dechlorination of Polychlorinated Biphenyls in Alkaline 2-Propanol Solutions

Abstract The radiolysis of solutions of polychlorinated biphenyls (PCB’s) and potassium hydroxide in simple aliphatic alcohols was studied. The major products in alkaline 2-propanol solutions were potassium chloride, acetone, lower chlorinated biphenyls, and biphenyl. Their yields increased and the concentration of the hydroxide ions decreased with the dose. Acetone and potassium chloride were formed in high yields, and their concentrations were almost equal to the diminution in the hydroxide ions. The dechlorination yield was determined as a function of the dose, the dose rate, and the concentrations of PCB’s, potassium hydroxide, and organic solutes. The chain-dechlorination reaction proceeded in the alkaline 2-propanol solution, but not in alkaline methanol, ethanol, 1-propanol, and butanols. The 2-propoxide radical anion, which is formed by the electron transfer from the hydroxide ion to the 2-propanol radical, is the chain carrier for the dechlorination reaction of PCB’s in alkaline 2-propanol solutions. The mechanism is discussed in detail.

Relation of core-level binding energy shifts to proton affinity and Lewis basicity

Gas-phase oxygen 1s binding energy shifts, ..delta..E/sub B/(O 1s), in simple aliphatic alcohols were found to decrease in the order: water > methyl > ethyl > isopropyl > teri-butyl. Comparison with potential-model calculations showed that the shifts are attributable to relaxation in the molecular ion final state (polarization effects) rather than to the initial-state charge distribution (inductive effects). The ability of methyl groups to stabilize charge in the ion is consistent with the observation of Brauman and Blair that the gas-phase acidity order is tert-butyl >...> H/sub 2/O. It was predicted that ..delta..E/sub B/(O 1s) approx. -..delta..(proton affinity) for these compounds. In fact the agreement between these two parameters is excellent; thus ..delta..E/sub b/(O 1s) appears to measure relative Bronsted basicities; the ..delta..E/sub B/(O 1s)vs. -(PA) relation may also be applicable to substituted alcohols (the CF/sub 3/CH/sub 2/OH point agrees very well with the above alcohols) and possibly to other functional groups. The N(1s) binding energy, which decreases in the order NH/sub 3/ > CH/sub 3/NH/sub 2/ > (CH/sub 3/)/sub 2/NH > (CH/sub 3/)/sub 2/N, shows excellent agreement with -..delta..(PA) in these compounds. The calculated relaxation-energy (or polarization) contribution to ..delta..E/sub B/ for both alcohols and amines agrees very wellmore » with the variation in the lone-pair ionization potential, thus giving quantitative support to a suggestion made by Price in 1947. The ..delta..E/sub B/ values for core electrons can be regarded as measuring Lewis basicity if the latter is extended to include nonbonding core orbitals. Thus I(3d/sub 5/2/) shifts in alkyl iodides are in excellent agreement with the O(1s) shifts in alcohols, with tert-butyl iodide being a stronger Lewis base than methyl iodide.« less

Photochemical Reactions of Uranyl Ions with Organic Compounds. V. Effects of Temperature and Solvent on the Photooxidation of Alcohols

Abstract A comparative study of the photokinetic behaviors of aliphatic alcohols and related substrates was made for the photooxidation with uranyl ions. Ethylene glycol, glucose, sucrose and some other substrates showed abnormal results compared to a series of simple aliphatic alcohols: the photoredox quantum yields φ for the former substrates decreased with substrate concentration (at their higher concentrations) and temperature rise, in contrast to simple aliphatic alcohols. In aqueous acetone solution φ increased with the increase in acetone content, the reaction constant ρ* being more negative than in aqueous solution. In 40% aqueous acetone solution the φ values for simple aliphatic alcohols varied in a complicated way with temperature. The abnormal results were interpreted in terms of the relative importance of physical quenching competing with the primary chemical process.

The Reaction of Dimeric Tri-O-acetyl-2-deoxy-2-nitroso-α-D-hexopyranosyl Chlorides with Alcohols

The kinetics of the reactions of dimeric tri-O-acetyl-2-deoxy-2-nitroso-α-D-glucopyranosyl chloride (1) with simple aliphatic alcohols (4 mol equiv) in dimethylformamide to form alkyl tri-O-acetyl-2-oximino-α-D-arabino-hexopyranosides (5) were investigated by n.m.r. and optical rotation. It is concluded that the conversion of 1 to 5 proceeds basically by way of three successively formed intermediates, namely, the monomeric form (2) of 1, the tri-O-acetyl-2-oximino-α-D-arabino-hexopyranosyl chloride (3), and the tri-O-acetyl-1,5-anhydro-2-deoxy-2-nitroso-D-arabino-hex-1-enitol (4). Direct evidence was obtained only for the intermediacy of 3 and the transient existence at low concentration of an uncharacterized intermediate which may be the β-anomer of 5. The intermediate 4 could form directly from 2 and thereby provide a mechanism for the formation of 5 which by-passes 3. However, the kinetic investigations showed this route to be of very minor, if any, importance. In all cases, the rate of the disappearance of 1 was virtually the same and within experimental error the same as for the isomerization of 1 to 3 in the absence of the alcohol for which the rate-controlling stage is dissociation of 1 to 2. Methanol reacts with 4 only about 5 times faster than does t-butanol.The utility of the reaction for the preparation of oximinoglycosidic structures related to disaccharides is illustrated by glycosidations of 1,2;3,4-di-O-isopropylidene-α-D-galactopyranose, 1,2;5,6-di-O-isopropylidene-α-D-glucofuranose both by 1 and by the dimeric tri-O-acetyl-2-deoxy-2-nitroso-α-D-galactopyranosyl chloride (6) and of 2,3;5,6-di-O-isopropylidene-α-D-mannofuranose by 1. The reaction of 6 with 1,2,3,4-di-O-isopropylidene-α-D-galactopyranose provided an 8.7% yield of the β-oximinoglycoside along with an 80% yield of the α-anomer.

Studies on the Proton Magnetic Resonance Spectra in Aliphatic Systems. V. Tris (dipivalomethanato) europium Induced Shift Parameters of Aliphatic Amines and Alcohols

The induced paramagnetic shift parameters, S values, of simple aliphatic amines and alcohols, and the α-substituted propane and β-substituted ethanol series were measured at a mole ratio of Eu (DPM)3/ligand in CDCl3 of below 0.10. The S value is a measure of the equilibrium between the shift reagent and ligand, for which the steric and electronic effects are responsible, and is expressed by the equation, S=A. e-BΔE where ΔE=ΔEelect+ΔEsteric

The kinetics and mechanism of the spontaneous alcoholysis of p-chlorophenyl isocyanate in diethyl ether. The association of alcohols in diethyl ether

The self-association of four simple aliphatic alcohols in ether solution has been investigated. In the concentration range 0·1–1·2 mol dm–3 the principal polymer is in every case the dimer. At 25 °C the dimerisation constants K2(=[dimer]/[monomer]2) have the values 0·49, 0·71, 0·50, and 0·72 for MeOH, EtOH, PriOH, and BunOH respectively. The kinetics of the spontaneous alcoholysis of p-chlorophenyl isocyanate by the same alcohols in ether solution has also been studied. The observed rate equation is –d[isocyanate]/dt= d[product]/dt={k2[M]2+Kn[M]n}[isocyanate] where [M] represents the alcohol monomer concentration, and n= 3 or 4 depending on the structure of the alcohol involved. The second-order term represents a route via dimeric alcohol. The various dimers have similar reactivities, the bulkier Bun and Pri substituents leading (at 25 °C) to species with about half the reactivity of dimeric methanol and ethanol. The higher-order term probably represents a route via trimeric or tetrameric alcohol. The contributions of the second- and of the higher-order terms to the overall rate are comparable, the latter dominating at high stoicheiometric concentrations. The probable mechanism of urethane formation is a slow, one-step cyclic addition of alcohol polymer to the isocyanate and is analogous to the mechanism of alcoholysis of ketens. The fact that alcoholysis of isocyanates involves, in almost all solvents, a kinetic order >1 in the stoicheiometric alcohol concentration arises from the generally greater reactivity of alcohol polymers than of monomers, and the circumstance that the relative concentration of the former inevitably rises as the stoicheiometric alcohol concentration increases.

On the use of simple aliphatic alcohols and acetone in extraction techniques: I. Tridodecylamine-hydrochloric acid-water system

On the use of simple aliphatic alcohols and acetone in extraction techniques: I. Tridodecylamine-hydrochloric acid-water system

Sulphation of simple aliphatic alcohols and bile alcohols by the toad Xenopus laevis.

Research Article| September 01 1970 Sulphation of simple aliphatic alcohols and bile alcohols by the toad Xenopus laevis M F Scully; M F Scully Search for other works by this author on: This Site PubMed Google Scholar K S Dodgson; K S Dodgson Search for other works by this author on: This Site PubMed Google Scholar F A Rose F A Rose Search for other works by this author on: This Site PubMed Google Scholar Biochem J (1970) 119 (3): 29P–30P. https://doi.org/10.1042/bj1190029P Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Cite Icon Cite Get Permissions Citation M F Scully, K S Dodgson, F A Rose; Sulphation of simple aliphatic alcohols and bile alcohols by the toad Xenopus laevis. Biochem J 1 September 1970; 119 (3): 29P–30P. doi: https://doi.org/10.1042/bj1190029P Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsBiochemical Journal Search Advanced Search This content is only available as a PDF. © 1970 The Biochemical Society1970 Article PDF first page preview Close Modal You do not currently have access to this content.

Infrared spectra: intramolecular trans lone pair interaction with α-CH bonds and the stability of conformers in alcohols and thiols

Doublet v(OH) bands in simple aliphatic alcohols due to rotational isomerism about the C-O bond are related to the number of α-CH bonds trans to an oxygen, lone pair orbital. v(OH) increases and v(α-OH) decreases when this condition is met. These frequency shifts can be rationalized by the participation of the oxygen lone pair in a σ * C-H orbital on the adjacent carbon, an interaction which appears to confer some stability on that conformer. This may be a significant factor governing rotational isomer populations in alcohols (and thiols). Specific studies of CH 3CD 2OH, (CH 3) 2CDOH and (CH 3) 2CDSH are reported. In aliphatic thiols the partial lone pair delocalization is found to be less significant, the overall order being N > O > S.

Electron spin resonance studies of reactions of some short–lived organic radicals in solution

A convenient method for studying short-lived organic radicals in solution is to combine e. s. r. spectroscopy with a fast-flow mixing system: solutions of materials which react to give the radicals are mixed a very short time before the combined solution passes through the cavity of the spectrometer. Dixon & Norman (1963) applied this principle to the reaction between acidified aqueous solutions of titanium (lll) ions and hydrogen peroxide; the reaction between these species rapidly produces the hydroxyl radical [Ti (lll) + H 2 O 2 → Ti (IV) + ·OH + OH-] and, when simple aliphatic alcohols are included in the reactants, the spectra of organic radicals derived by the abstraction of a hydrogen atom from a C—H bond of the alcohol are observed (e. g. CH 3 OH + ·OH → ·CH 2 OH + H 2 O). Dixon, Norman & Buley (1964) showed that other types of saturated aliphatic compound also undergo abstraction of hydrogen to give observable radicals, Dixon & Norman (1964) showed that benzene forms an adduct with the hydroxyl radical, and Fischer (1964) showed that olefins likewise form adducts. The reactions of olefins are of particular interest in that, for those which are polymerizable, it is possible to derive informa­tion about the characteristics of the polymerizations by examining the effects on the e. s. r. spectra of changes in the concentrations of the reactants. Since the original studies of this type, it has become apparent that the titanous-peroxide system itself is more complex than was first thought. When the reactants are mixed in the absence of an organic compound, either one or two singlets are observed in the spectrum, depending on the relative concentrations of the re­actants. The simplest explanation would be that these are the spectra of the radicals ·OH and ·O 2 H, the latter radical being formed by the reaction of the former with excess of hydrogen peroxide and so increasing in concentration relative to the former radical as the ratio [H 2 O 2 ] : [Ti (lll)] is increased. However, Chiang, Craddock, Mickewich & Turkevich (1966) adduced evidence that the two radicals responsible for these e. s. r. singlets are complexes of oxy-radicals and titanium ions, and more recently Fischer (personal communication) has confirmed this by observing satellite lines for each singlet ascribable to interaction of the unpaired spin in an oxy-radical with the (low-abundant) paramagnetic 47 Ti and 49 Ti nuclei. Moreover, we have found at York that, when titanium (lll) ions and hydrogen peroxide react a short time before an organic reactant such as methanol is introduced, only the singlets are observed. This implies that the singlets are due to relatively unreactive radicals, and that, unless organic compounds are available for reaction immediately the hydroxyl radical is generated, this radical is efficiently scavenged by titanium-containing species. None the less, despite this complexity, there is no reason to doubt that, when an organic compound is available at the point of mixing of the titanium and peroxide reactants, the chemistry with which we are concerned is that of the reaction of the hydroxyl radical with the organic compound. The remainder of this paper will describe reaction processes which are initiated in this way.