Alcohols t -butyl

This then is the disconnection corresponding to the reaction. It is the thinking device we use to help us work out a synthesis of t-butyl alcohol. We could of course have broken any other bond in the target molecule such as ... 

Potassium t-butoxide in t-butyl alcohol requires powerful electron-attracting substituents at C-4 to effect ring opening of pyrazoles but sodamide does not (Scheme 26) (B-76MI40402). As the key to the transformation is the generation of the anion, similar results were obtained by heating some pyrazole-3-carboxylic acids with quinoline. 

As soon as the receiver containing the methyl 11 thiurn solution has been removed and stoppered, the residual solids in the reaction flask and the filtration apparatus should be rinsed Into another receiver with anhydrous ether under an atmosphere of argon or nitrogen. The ether slurry of solids, which may contain some unchanged lithium metal, should be treated cautiously in a hood with t-butyl alcohol to consume any residual lithium metal before the mixture is discarded. 

The A-ring of the 17-ol (25) derived from equilenin 3-methyl ether is reduced rapidly under Birch reduction conditions, since the 1,4-positions are unsubstituted. The B-ring is reduced at a much slower rate, as is characteristic of aromatic compounds in which 1,4-reduction can occur only if a proton enters an alkylated position. Treatment of (25) with sodium and t-butyl alcohol in ammonia reduces only the A-ring to afford the corresponding 1,4-dihydro compound in over 85% yield.On the other hand,... 

When 16-dehydropregnenolone itself is reduced, less than 3 % of the starting material remains unreduced and reduction of the tetrahydropyranyl ether of 16-dehydropregnenolone (70) in the presence of one mole of t-butyl alcohol is also virtually complete. In both cases, however, crystallization of the crude products gives only modest yields of pure products. 

Birch Reductions in Ammonia-Tetrahydrofuran-t-Butyl Alcohol ... 

Reductions with alcohols other than t-butyl alcohol are carried out using the general procedure given above and replacing the -butyl alcohol by an equivalent amount of the other alcohol. 

In a special case involving a C-ring aza steroid, it was found that epoxida-tion of a A -20-keto grouping using a two-phase system (t-butyl alcohol-aqueous potassium hydroxide-30 % hydrogen peroxide) was much superior to the standard hydrogen peroxide-aqueous methanolic alkali conditions. 

Step 3 in Figure 5.6 shows water as the base which abstracts a proton from the car-bocation. Other Bronsted bases present in the reaction mixture that can function in the same way include te/t-butyl alcohol and hydrogen sulfate ion. 

The infrared spectra of alcohols change markedly with increasing concentration. For example, at very low concentration, the infrared spectrum of te/t-butyl alcohol in carbon tetrachloride contains a single sharp band at approximately 3600 cm corresponding to the OH stretching motion. As the alcohol s concentration increases (by adding more alcohol to the sample), a second broad OH stretch band grows in at approximately 3400 cm and eventually replaces the other band. 

The dropping funnel is charged with a solution of 7.7 g (0.05 mole) of 4-/-butylcyclo-hexanone (Chapter 1, Section 1) in 50 ml of dry ether. The solution is slowly added to the mixed hydride solution at a rate so as to maintain a gentle reflux. The reaction mixture is then refluxed for an additional 2 hours. Excess hydride is consumed by the addition of 1 ml of dry t-butyl alcohol, and the mixture is refluxed for 30 minutes more. 4-/-Butylcyclohexanone (0.3 g) in 5 ml of dry ether is added to the reaction mixture, and refluxing is continued for 4 hours. The cooled (ice bath) reaction mixture is decomposed by the addition of 10 ml of water followed by 25 ml of 10% aqueous sulfuric acid. The ether layer is separated, and the aqueous layer is extracted with 20 ml of ether. The combined ether extracts are washed with water and dried over anhydrous magnesium sulfate. After filtration, the ether is removed (rotary evaporator), and the residue... 

A dry 5(X)-mI flask equipped with a thermometer, pressure-equalizing dropping funnel, and magnetic stirrer is flushed with nitrogen and then maintained under a static pressure of the gas. The flask is charged with 50 ml of tetrahydrofuran and 13.3 ml (0.15 mole) of cyclopentene, and then is cooled in an ice bath. Conversion to tricyclo-pentylborane is achieved by dropwise addition of 25 ml of a 1 M solution of diborane (0.15 mole of hydride see Chapter 4, Section 1 for preparation) in tetrahydrofuran. The solution is stirred for 1 hour at 25° and again cooled in an ice bath, and 25 ml of dry t-butyl alcohol is added, followed by 5.5 ml (0.05 mole) of ethyl bromoacetate. Potassium t-butoxide in /-butyl alcohol (50 ml of a 1 M solution) is added over a period of 10 minutes. There is an immediate precipitation of potassium bromide. The reaction mixture is filtered from the potassium bromide and distilled. Ethyl cyclopentylacetate, bp 101730 mm, 1.4398, is obtained in about 75% yield. Similarly, the reaction can be applied to a variety of olefins including 2-butene, cyclohexene, and norbornene. 

A l-Iiter, three-necked, round-bottom flask is equipped with a mechanical stirrer, a thermometer immersed in the reaction mixture, a dropping funnel, and a gas vent. In the flask is placed a mixture of 96% sulfuric acid (25.5 ml, 470 g, 4.8 mole), carbon tetrachloride (100 ml), and adamantane (13.6 g, 0.10 mole), and the mixture is cooled to 15-20° with rapid stirring in an ice bath. One milliliter of 98% formic acid is added and the mixture is stirred until the evolution of carbon monoxide is rapid (about 5 minutes). A solution of 29.6 g (38 ml, 0.40 mole) of t-butyl alcohol in 55 g (1.2 mole) of 98-100% formic acid is then added dropwise to the stirred mixture over 1-2 hours, the temperature being maintained at 15-20°. After stirring for an additional 30 minutes, the mixture is poured onto 700 g of ice, the layers are separated, and the aqueous (upper) layer is extracted three times with lOO-ml portions of carbon tetrachloride. The combined carbon tetrachloride solutions are shaken with 110 ml of 15 A ammonium hydroxide, whereupon ammonium 1-adamantanecarboxylate forms as a crystalline solid. This precipitate is collected by filtration through a fritted glass funnel and washed... 

B) t-Butyl 2-Methyl-5-Methoxy-3-lndolylacetate t-Butyl alcohol (25 ml) and fused zinc chloride (0.3 g) are added to the anhydride from Part A. The solution is refluxed for 16 hours and excess alcohol is removed in vacuo. The residue is dissolved in ether, washed several times with saturated bicarbonate, water, and saturated salt solution. After drying over magnesium sulfate, the solution is treated with charcoal, evaporated, and flushed several times with Skellysolve B for complete removal of alcohol. The residual oily ester (18 g, 93%) is used without purification. 

The cyclization of aryl 3-chloropropyl sulfones by potassium t-butoxide in t-butyl alcohol at 30 °C (equation 20) has a p value of 2.32 for substituents in Ar202. This is considered by Bird and Stirling to indicate the formation of an intermediate carbanion which is essentially in equilibrium with the reactants. A recent review by Stirling203 deals with structure-reactivity aspects of many sulfonyl promoted reactions of this type. 

Vinyl sulfones such as 262 are smoothly converted to a,) -unsaturated nitriles such as 263 on treatment with KCN in the presence of dicyclohexyl-18-crown-6 in refluxing t-butyl alcohol (equation 155)148. The reaction conditions are compatible with base-labile functionalities such as a methoxycarbonyl group (equation 156)148. This method can be used in the preparation of the sesquiterpene aldehyde nuciferal from allyl phenyl sulfones. 

The common names of 2-methyl-2-propanol are tertiary-butanol and tertiary-butyl alcohol (commonly shortened to tert-butanol and tert-butyl alcohol or even t-butanol and t-butyl alcohol). 

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