N Butyl />-toluenesulfonate

To a mixture of 1-methoxy-l,3-butadiene (1 55.3 g, 0.66 mol) [43] and n-butyl glyoxylate (86.0 g, 0.66mol) [44], 0.1 g hydroquinone was added and the solution was refluxed at 100°C for 6 h under argon. Distillation at 88°-90°C/0.5 tonr gave 2 (R = Bu) (91.6 g, 65%) as a pale-yellow liquid with a faint odor. By gas chromatography this product is a mixture of cis and trans (ca. 7 3) isomers. Treatment of the isomer mixture in dichloro-methane solution with p-toluenesulfonic acid or zinc chloride for 2 h leads to an almost pure trans-isomer (ca. 95%). 

M-Butylbenzene has been prepared by the action of sodium (a) on benzyl chloride or bromide and w-propyl bromide without diluents,1 or (b) on n butyl bromide and bromobenzene without a solvent2 or in benzene 3 by a Clemmensen reduction of ra-butyr-ophenone 4 and by the action of benzylmagnesium chloride on M-propyl />-toluenesulfonate.5 Other procedures do not appear to be of preparative value. 

Potassium cyanide has been caused to react with salts and esters of sulfonic acids to give nitriles. Thus, an intimate mixture of finely powdered potassium cyanide with the compound may be fused 422 this method was successfully applied428 to tetrahydrofurfuryl p-toluenesul-fonate and methanesulfonate, but failed with l,2 3,4-di-0-isopropylidene-6-O-tosyl-D-galactose. Another method, consisting of treatment of the ester with a stirred, boiling, saturated, aqueous solution of potassium cyanide gave885 a 70 to 83% yield of nitrile with primary p-toluenesul-fonates (ethyl, n-butyl, and n-octyl) and a 43% yield with a secondary p-toluenesulfonate (isopropyl). Similar methods had been applied earlier98 841 to such simple esters, but have not apparently found use with sulfonic esters of carbohydrates. 

Moreover, the formation of enoxy-silanes via silylation of ketones127 by means of N-methyl-N-TMS-acetamide (1 72) in presence of sodium trimethylsilanolate (173) was reported in 1969 and since then, the use of silylating reagents in presence of a catalyst has found wide appreciation and growing utilization as shown in recent papers128-132 (Scheme 27). Diacetyl (181) can be converted by trifluoromethylsul-fonic acid-TMS-ester (182) into 2,3-bis(trimethylsiloxy)-l, 3-butadiene (7treatment with ethyl TMS acetate (7 5)/tetrakis(n-butyl)amine fluoride l-trimethylsiloxy-2-methyl-styrene (i<56)130. Cyclohexanone reacts with the combination dimethyl-TMS-amine (18 7)/p-toluenesulfonic acid to 1-trimethylsiloxy-l-cyclohexene (iSS)131. Similarly, acetylacetone plus phenyl-triethylsilyl-sulfide (189) afford 2-triethylsiloxy-2-pentene-4-one (790)132. ... 

The Step 1 product was stirred at 125°C in n-butyl acetate with /t-toluenesulfonic acid, then cooled, filtered, and washed with water. The mixture was then treated with water, ethyl alcohol, chlorotris(triphenylphosphine)rhodium, degassed, and heated for 3-5 hours at 75°C. The racemic acid was extracted with 2M NaOH, then washed with butyl acetate. It was then treated with methyl alcohol followed by the slow addition of 2 M HC1 and the product isolated by filtration. The material was used directly without further purification. 

From Di-m-butyl Formal. When 2-butyne-l,4-diol and di-n-butyl formal were allowed to react as described above, in the presence of a catalytic amount of p-toluenesulfonic acid at temperatures up to 190° C., nearly two equivalents of n-butyl alcohol distilled off. The product was a mushy, light brown solid of molecular weight 475, as determined cryoscopically in benzene. 

Acetylation of alcohols and phenols by ketene has limited use. Unless apparatus for the preparation of ketene is readily available, less troublesome methods can usually be found. Worthy of mention, however, are the acetylations of lactic esters in 94-98% yields and of tertiary alcohols and phenols in 89-96% yields.Catalysts are necessary even to convert a high percentage of n-butyl alcohol to n-butyl acetate. Sulfuric and p-toluenesulfonic acids are commonly used. Certain aldehydes and ketones are attacked by ketene. Acetates of enol forms of ketones may be made in this way. ° Under certain conditions / -lactones are formed (cf. method 327),... 

Esters of aliphatic and aromatic sulfonic acids are conveniently prepared in high yields from alcohols and sulfonyl halides. A basic medium is required. By substituting sodium butoxide for sodium hydroxide in butanol, the yield of n-butyl p-toluenesulfonate is increased from 54% to 98%. Ethyl benzenesulfonate and nuclear-substituted derivatives carrying bromo, methoxyl, and nirro groups are prepared from the corresponding sulfonyl chlorides by treatment with sodium ethoxide in absolute ethanol the yields are 74-81%. Pyridine is by far the most popular basic medium for this reaction. Alcohols (C -Cjj) react at 0-10° in 80-90% yields, and various phenols can be converted to aryl sulfonates in this base. "... 

CyclopropanecarboxaUehytte. Dehydration of a mixture of cis- and froni-cyclo-butane-l,2-diol (I) with boron trifluoride n-butyl etherate at 230° yields cyclopropane-carboxaldehyde (2) in 65-80% yield. Dehydration of (I) with p-toluenesulfonic acid gives (2) in somewhat lower yields (66%)- ... 

Enol acetylation (I, 1174 1178). As a Grst step in the synthesis of 3-n-butyl-2,4-pentanedione, a mixture of 28.6 g. (0.25 mole) of 2-heptanone, 51.0 g. (0.50 mole) of acetic anhydride, and 1.9 g. (0.01 mole) of p-toluenesulfonic acid monohydrate contained in a stoppered 500-ml. round-bottomed flask equipped with a magnetic stirrer is stirred at room temperature for 30 min. Then 55 g. (0.43 mole) of the I 1 boron trifluoridc-acetic acid complex [Reagents, I, 69 (1967)] is added some heat is evolved... 

C11H16O3S, n-Butyl p-toluenesulfonate 67 CiiHsiBr02, 11-Bromoundecanoic acid 62... 

Benzenesulfonate or p-toluenesulfonate esters of 1,3 glycols frequently give better yields of thietanes than the 1,3-dihalides. Sodium sulfide in dimethyl sulfoxide, diethylene glycol, " aqueous n-butyl alcohol, 1,2-... 

Addition to a,p-unsaturated ethers. In the presence of a catalytic amount of p-toluenesulfonic acid, isocyanic acid adds to vinyl n-butyl ether to give 1-butoxy-ethyl isocyanate in high yield. ... 

When this same tetrol was condensed with 1,4-cyclohexanedione in n-butyl ether in the presence of a trace of jv-toluenesulfonic acid, a nearly quantitative yield of a white polymer VII was obtained. This material did not melt, but was soluble in hexa-fluoroisopropanol and had an [n] of 0.04 dl/g (25 , hexafluoro-isopropanol). This polymer VII was found to be highly crystalline by X-ray powder pattern and had a T. in the DTA apparatus of 400°. 1/Z... 

Polymer VII from 1,4-Cyclohexanedione and 1,2,4,5-Tetrakis-(hydroxymethvl) cyclohexane. Into a 100—ml flask equipped with a mag. stirrer, a Dean-Stark trap, a reflux condenser and a drying tube were added 50 ml of dry n-butyl ether, 2.04 g of 1,2,4,5-tetrakis(hydroxymethyl)cyclohexane and 1.12 g of 1,4-cyclohexanedione. The solution-suspension was heated under reflux for 12 hours followed by the addition of 0.1 g of -toluenesulfonic acid. After the mixture was heated overnight, it was cooled to room temperature. The mixture was filtered with suction and the resulting solid was washed well with n-butyl ether. After most of the ether was removed, the solid was washed with water, acetone and finally ether. The solid, which was dried over P2O5 and under 0.2 mm pressure, weighted 3.1 g (99%). The solid was soluble only in hexafluoroisopropanol and had an [T ] of 0.04 dl/g at 25°c. The polymer was found to be crystalline by X-ray and did not melt. 

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