T-Amyl alcohol

Birch reduction of the diethyl ketal of estrone 3-methyl ether in ammonia-methylcyclohexane-t-amyl alcohol,... 

The interaction of (10) with vinylmagnesiiim chloride yields, after hydrolysis of the ketal group, 46% of the 3a-vinyl-l7-ketone (11b) and 7% of the 3j5-vinyl-17-ketone (12b). Ethynylation of (10) with potassium acetylide in dimethylformamide or with acetylene and potassium t-amyloxide in t-amyl alcohol-ether gives only the 3a-ethynyl derivative (11c) in 63% and 74% yields, respectively. ... 

A macroporous polystyrene-divinylbenzene copolymer, produced by copolymerizing a mixture of styrene and divinylbenzene, is dissolved in an organic liquid such as t-amyl alcohol or isooctane, which is a solvent for monomers. This solvent is unable to substantially swell the resulting copolymer. Macroporous cation-exchange beads are also produced from these macroporous copolymers (25,26). 

Base-catalyzed Diels-Alder reactions are rare (Section 1.4). A recent example is the reaction of 3-hydroxy-2-pyrone (145) with chiral N-acryloyl oxazolidones 146 that uses cinchona alkaloid as an optically active base catalyst [97] (Table 4.25). Only endo adducts were obtained with the more reactive dienophile 146 (R = H), the best diastereoselectivity and yields being obtained with an i-Pr0H/H20 ratio of 95 5. The reaction of 146 (R = Me) is very slow, and a good adduct yield was only obtained when the reaction was carried out in bulky alcohols such as t-amyl alcohol and t-butanol. 

Of course, the influence of organic solvents on enzyme enantioselectivity is not limited to proteases but it is a general phenomenon. Quite soon, different research groups described the results obtained with lipases [28]. For instance, the resolution of the mucolytic drug ( )-trans-sobrerol (11) was achieved by transesteriflcation with vinyl acetate catalyzed by the lipase from Pseudomonas cepacia adsorbed on celite in various solvents. As depicted in Scheme 1.3 and Table 1.5, it was found that t-amyl alcohol was the solvent of choice in this medium, the selectivity was so high ( >500) that the reaction stopped spontaneously at 50% conversion giving both +)4rans-sobrerol and (—)-trans-sobrerol monoacetate in 100% optical purity [29]. 

C16H33NMe2CH2CH2OH Br, aq.NaOH, octane, t-amyl alcohol. Reaction involves phosphorylation of the functional surfactant... 

CTABr, t-amyl alcohol, aq.NaOH. Second-order rate constants in the microemulsion droplets calculated. 

CTABr or C16H33NMe2CH2CH2OH Br , t-amyl alcohol or 1-butanol, aq.NaOH. Overall reaction rates and products examined... 

When alcohols such as t-butyl alcohol, t-amyl alcohol, t-hexyl alcohol, were dissolved in fluorosulphonic acid-antimony pentafluoride solutions diluted with sulphur dioxide (in order to achieve better mixing of the less viscous solutions and to avoid the possibility of local overheating) at temperatures ranging around — 60°, stable, slightly coloured solutions... 

Complexes of other metals are also capable of catalyzing useful carbonylation reactions under phase transfer conditions. For example, certain palladium(o) catalysts, like Co2(C0)g, can catalyze the carbonylation of benzylic halides to carboxylic acids. When applied to vinylic dibromides, unsaturated diacids or diynes were obtained, using Pd(diphos)2[diphos l,2-bis(diphenylphosphino)ethane] as the metal catalyst, benzyltriethylammonium chloride as the phase transfer agent, and t-amyl alcohol or benzene as the organic phase(18),... 

The reduction is carried out much as described in Procedure 2. Ammonia (950 ml) is distilled into a 5-liter reaction flask and 950 ml of t-amyl alcohol and a solution of the ketal in 950 ml of methylcyclohexane are added with good stirring. Sodium (57 g, 2.5 g-atoms) is added in portions. The reaction mixture becomes blue within 30-45 min after the sodium is added and the metal is consumed within about 3 hr after the blue color appears. After the mixture becomes colorless, 200 ml of ethanol is added and the ammonia is allowed to boil off through a mercury trap. Then 500 ml of water and 500 ml of 10% potassium bicarbonate solution are added and the organic layer is separated. The organic layer is washed once with 10 % potassium bicarbonate... 

The 3-acylbenzo[6]thiophenes, separated from the mixture obtained on acylation of benzo[6]thiophene (Section 3.14.2.4), are readily reduced to 3-alkylbenzo[6]thiophenes. 3-Benzo[6 ]thienyllithium can be prepared from 3-bromobenzo[6]thiophene at -70 °C (68JCS2733) and this may serve as a source of 3-acylbenzo[Z>]thiophenes. In certain instances, Friedel-Crafts alkylation gives the 3-substituted benzo[6]thiophenes nearly exclusively. For example, 3-t-amylbenzo[6]thiophene was the exclusive product of alkylation of benzo[6 Jthiophene with t-amyl alcohol in the presence of tin(IV) chloride <70AHC(11)177). 

Reduction of ketones. Reduction of ketones with metals in an alcohol is one of the earliest methods for effecting reduction of ketones, and is still useful since it can proceed with stereoselectivity opposite to that obtained with metal hydrides.1 An example is the reduction of the 3a-hydroxy-7-ketocholanic acid 1 to the diols 2 and 3. The former, ursodesoxycholic acid, a rare bile acid found in bear bile, is used in medicine for dissolution of gallstones. The stereochemistry is strongly dependent on the nature of the reducing agent (equation I).2 Sodium dithionite and sodium borohydride reductions result mainly in the 7a-alcohol, whereas reductions with sodium or potassium in an alcohol favor reduction to the 7p-alcohol. More recently3 reduction of 1 to 2 and 3 in the ratio 96 4 has been achieved with K, Rb, and Cs in f-amyl alcohol. Almost the same stereoselectivity can be obtained by addition of potassium, rubidium, or cesium salts to reductions of sodium in t-amyl alcohol. This cation effect has not been observed previously. 

Nickel affords selective catalysts for the hydrogenation of alkenes, dienes, and alkynes. When catalyzed by C. A. Brown s P-2 nickel, prepared by the reduction of Ni(0Ac)2 with NaBH in ethanol, the individual rates as well as the competitive rates appear to be sensitive to the alkene structure as judged by the reported initial rates of hydrogen addition (ref. 23). Alkene isomerization is relatively slow. Except for the most reactive alkenes such as norbornene, the individual hydrogenations seem to be first order in alkene. This indicates that alkenes are more weakly bound to Ni than to Pt or Pd. Similar selectivities are reported by Brunet, Gallois, and Caubere for a catalyst prepared by the reduction of Ni(0Ac)2 with NaH and t-amyl alcohol in THF (ref. 27). 

The interior of the CD bucket offers an environment with a much smaller dielectric constant than that of aqueous solution. The microscopic polarity of the cavity has been estimated to be similar to that of dioxane, 1-octanol, isopropyl ether, and t-amyl alcohol [137], Hence, compounds that normally exhibit intense fluorescence in organic solvents will exhibit comparable emission intensity from aqueous solutions if CD is present [136,227-230]. 

Fig. 19. Lightscattering data for AOT in t-amyl alcohol (square points) and in t-amyl alcohol diluted with nonane (round points). Open and solid points represent Hg-green and blue line data, respectively. [J. Colloid Interface Sci. 29, 6 (1969)]...

Butyl lithium t-Amyl alcohol Citric acid Triethylamine Salicylaldehyde Morpholine Sodium azide... 

N-Carbobenzoxy-3-fluoro-4-morpholinylaniline (3.00 mmol, 1.000 eq) and tetrahydrofuran (3.5 ml) were agitated and cooled. The lithium t-amylate mixture [prepared in THF at 25°C from t-amyl alcohol (0.66 ml, 6.03 mmol, 2.00 eq) and butyl lithium (1.8 ml, 2.5 M in hexanes, 4.55 mmol, 1.5 eq)] is then added to the carbamate mixture at less than 8°C and rinsed in with THF (1 ml). 

A vial containing ( )-4-phenyl-3-butyn-2-ol (73.0 mg, 0.5 mmol) and catalyst (3.3 mg, 5.0 pmol) in t-amyl alcohol (1.0 mL) was capped with a septum and sonicated to assist catalyst dissolution. The resulting purple solution was cooled to 0 °C, and Ac20 (35.4 pL, 0.375 mmol) was added via a syringe. After 49 h, the reaction mixture was quenched by the addition of a large excess of MeOH. After concentration in vacuo, the residue was purified by FC on silica gel (EtOAchexanes, 1 9 to 1 1, then EtOAc hexanes EtsN, 9 9 2) to afford the (R)-acetate (68.6% ee by chiral-GC) and the (S)-alcohol (96.0% ee by chiral-GC on the acetate obtained following esterification). The calculated selectivity value at 58.3% conversion was s = 20.2. 

Alkanols with fewer than five carbon atoms t-Amyl alcohol... 

A wide variety of organic solvents has been used to conduct bioconversions including nonpolar solvents such as isooctane, n-hexane, and toluene, in addition to methanol, acetone, and other water-miscible solvents. Dipolar aprotic solvents dimethylformamide (DMF) and dimethylsulfoxide (DMSO) are also compatible with many enzymes and are often used to enhance the solubility of substrates in combination with a nonpolar solvent. Tertiary alcohols such as f-butanol and t-amyl alcohol have been used for many lipase-mediated esterifications as the hindered tertiary alcohol is not typically a good substrate for most enzymes. It should be noted that the presence of small amounts of water is essential for the effective use of most biocatalysts in organic solvents. In some cases an enzyme may only require a monolayer of water molecules on its surface in order to operate. In other cases there may need to be enough water to form reverse micelles where the biocatalyst is contained within a predominantly aqueous... 

The mobile phases used in the development of thin-layer chromatography plates are usually combinations of organic and aqueous solvents. Ethanol, t-amyl alcohol, acetonitrile, and methanol are commonly used organic solvents. Acetic acid is the most commonly used aqueous solvent. In normal-phase partition chromatography the polar stationary phase is developed with relatively nonpolar mo-... 

Mobile phase for thin-layer chromatography—Mix 1.5 liters of chloroform, 600 ml of t-amyl alcohol, and 60 ml of glacial acetic acid. Store tightly covered in a dark bottle at room temperature. 

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