Aluminum ferf.-butoxide

Commercial tert.-butyl alcohol dried over calcium oxide is suitable for this preparation. Aluminum isopropoxide or ethoxide 2 may be used in place of the aluminum /er/.-butoxide to remove traces of water. The grade of metal known as fast cutting rods has proved most satisfactory. The checkers used turnings made from aluminum cast from melted-down kitchen utensils. Aluminum ferf.-butoxide has also been prepared successfully in another laboratory from commercially pure aluminum (2S) and from rods of the alloy 17ST (communication from L. F. Fieser). The checkers were able to obtain considerably higher yields of the butoxide from pure aluminum than from a copper-bearing alloy. 

The Oppenauer Oxidation. When a ketone in the presence of an aluminum alkoxide is used as the oxidizing agent (it is reduced to a secondary alcohol), the reaction is known as the Oppenauer oxidation. This is the reverse of the Meerwein-Ponndorf-Verley reaction (19-36) and the mechanism is also the reverse. The ketones most commonly used are acetone, butanone, and cyclohexanone. The most common base is aluminum ferf-butoxide. The chief advantage of the method is its high selectivity. Although the method is most often used for the preparation of ketones, it has also been used for aldehydes. An iridium catalyst has been developed for the Oppenauer oxidation, and also a water-soluble iridium catalyst An uncatalyzed reaction under supercritical conditions was reported. 

Distilled ethyl oleate (200 g, 0.65 mole) and absolute alcohol (1.51) are placed in a 5-1 round-bottomed flask under a wide reflux condenser. The alcohol has been previously dried over calcium and is distilled from aluminum ferf-butoxide directly into the reaction flask. Sodium (to a total of 80 g, 3.5 gram-atoms) is added gradually through the reflux condenser at such a rate that vigorous reaction ensues, the flask being occasionally shaken. When the main reaction has ended, more absolute alcohol (200 ml) is added and the mixture is heated on the steam-bath until all the sodium is consumed. Then water (500 ml) is added and the heating continued for a further hour to hydrolyse unchanged ester. The imsaponifiable fraction is extracted with ether. The ether extract is washed with 1 % potassium hydroxide solution and then with water until free from alkali (phenolphthalein) and is dried over sodium sulfate. The ether is distilled off and the residue is fractionally distilled. 49-51 % (84-89 g) of oleyl alcohol are obtained at 150-152°/1 mm. 

Di-0-isopropylidene-a-D-rtbo-hexofuranos-3-ulose (100) was treated with (chlorofluoromethylene)triphenylphosphorane (prepared by reaction of triphenylphosphine on difluorocarbene generated in situ by reaction of potassium ferf-butoxide with dichloro-fluoromethane), to give cis- and rans-3-C-(chlorofluoromethylene)-3-deoxy-l,2 5,6-di-0-isopropylidene-a-D-ribo- (101 and 103) and -xyfo-hexofuranoses (105 and 107), which, on treatment with lithium aluminum hydride, gave cis- and frans-3-deoxy-3-C-(fluoromethyl)-1,2 5,6-di-O-isopropylidene-a-D-rtbo- (102 and 104) and -xyZo-hexofura-... 

In a i-l. round-bottomed, three-necked flask, fitted with a thermometer, an efficient mechanical stirrer (Note i), and a 35-cm. Vigreux column fitted to a condenser and receiver protected by a calcium chloride tube, are placed 345 g. (400 cc.) of dry xylene, 120 g. (117 cc., 1 mole) of dry acetophenone, and 135 g. (0.55 mole) of aluminum fer/.-butoxide (p. 8) (Note 2). The stirrer is started and the flask heated in an oil bath so that the temperature of the reaction mixture is held between 1330 and 1370. ferf.-Butyl alcohol slowly distils at a temperature in the vapor of 80-85°. The distillation of the alcohol can be accomplished by maintaining the temperature of the heating bath between 150° and 155° for two hours after distillation has commenced (Notes 3 and 4). 

See Section 16-4E often useful for low-boiling aldehydes that can be distilled out of mixture as formed, thereby preventing condensation reactions aluminum isopropoxide or ferf-butoxide commonly are used as catalysts carbon-carbon double bonds are not attacked. 

Pinocarveol has been prepared by the autoxidation of a-pinene,5 by the oxidation of /S-pinene with lead tetraacetate,6 and by isomerization of a-pinene oxide with diisobutylalumi-num,7 lithium aluminum hydride,8 activated alumina,9 potassium ferf-butoxide in dimethylsulfoxide,10 and lithium diethylamide.11 The present method is preferred for the preparation of pinocarveol, since the others give mixtures of products. It also illustrates a general method for converting 1-methylcy-cloalkene oxides into the corresponding exocyclic methylene alcohols.11 The reaction is easy to perform, and the yields are generally high. 

METHYL HYDRATE (67-56-1) CH O CH3OH Flammable liquid. Forms explosive mixture with air [explosion limits in air (vol %) 6.0 to 36.5 flash point 52 F/11 C autoignition temp 725°F/385°C 867°F/464°C " Fire Rating 3]. Violent reaction (possible fire and/or explosion) with strong oxidizers strong mineral acids (e.g., nitric, sulfuric, perchloric) acetyl bromide alkyl aluminum salts beryllium dihydride bromine, chromic acid l-chloro-3,3-difluoro-2-methoxycyclopropene, cyanuric chloride diethylzinc, isophthaloyl chloride potassium-ferf-butoxide phosphorus trioxide platinum-black catalyst (ignition) potassium sulfur diimide Raney-nickel catalysts 2,4,6-trichlorotriazine, triethylaluminum, 1,3,3 -trifluor o-2 -... 

CARBONATO de METILO (Spanish) (616-38-6) Forms explosive mixture with air (flash point 66°F/19°C oc). Reacts violently with strong oxidizers, strong bases, potassium-ferf-butoxide. Incompatible with sulfuric acid, aliphatic amines, alkanolamines, amides, organic anhydrides, isocyanates, vinyl acetate, alkylene oxides, epichlorohydrin. Incompatible with aluminum, magnesium, silicone. Flow or agitation of substance may generate electrostatic charges due to low conductivity. 

Methylene chloride is a noncombustible liquid. It reacts explosively with alkali metals and their alloys, and with powdered magnesium or aluminum. Ignition occurs with potassium ferf-butoxide. It forms explosive mixtures with nitrogen tetroxide (Turley... 

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