Alcohols, olefinic esters

Oxidative Garbonylation. Carbon monoxide is rapidly oxidized to carbon dioxide however, under proper conditions, carbon monoxide and oxygen react with organic molecules to form carboxyUc acids or esters. With olefins, unsaturated carboxyUc acids are produced, whereas alcohols yield esters of carbonic or oxalic acid. The formation of acryUc and methacrylic acid is carried out in the Hquid phase at 10 MPa (100 atm) and 110°C using palladium chloride or rhenium chloride catalysts (eq. 19) (64,65). 

An important feature of sulfation chemistry is the thermal instability of the acid sulfate, which breaks down to a mixture of products including the parent alcohol, the dialkyl sulfate (R0S020R), the dialkyl ether (ROR), isomeric alcohols, olefins (R CH=CH2), and esters (R0S03R). Because of the thermal instability of the acid sulfate it is necessary to avoid high sulfation temperatures and to neutralize the acid sulfation product soon after its formation. An aging time of about 1 min at 30-50°C is adequate for the second reaction whereby the desired alkyl hydrogen sulfate is formed. In practice the minimum sulfation feasible temperature is determined by the need for the feedstock and reaction mixture to be mobile liquids (Table 3). 

Alcohols and esters, made not from olefins, but from saturated hydrocarbons in this case, pentanes, were next on the scene, with the production in 1926 of amyl alcohol by chlorination and caustic hydrolysis. And shortly thereafter thfe intentional chlorination of ethylene was undertaken to expand the output of ethylene dichloride, formerly obtained as a by-product of glycol manufacture. 

T he oxidation of olefins by selenium dioxide has received much atten-- tion because of the unique characteristics of the reaction that produces an allylic derivative of the olefin (ester, alcohol, or ether, depending upon the solvent) and elemental selenium as the final reduced state of the oxidant. 

The aluminum alkoxide mixture or "oxidized growth product is fed to a series of vacuum flash evaporators to remove solvent introduced earlier in the triethylaluminum preparation. This vacuum stripping step also removes olefins formed during the growth reaction and the myriad of by-products formed during oxidation (14) Efficiency of this stripping process is a key factor in alcohol product quality. This is the opportunity to separate volatile impurities—olefins, esters, aldehydes, paraffins, etc.—from product alcohols while the alcohols are in a nonvolatile form (aluminum alkoxides). 

Isopropyl anisole (171) was converted to bromide (172) by metalation, formylation and bromination. Alkylation with cyclopropyl ketoester produced (173) whose transformation to alcohol (174) was achieved by saponification, decarboxylation and reduction.. Its conversion to homoallylic bromide (175) was accomplished by the method of Julia et al. [56]. Alkylation of ethyl acetoacetate with bromide (175) furnished p-ketoester (176). It was subjected to cyclization with stannic chloride in dichloromethane. The resulting tricyclic alcohol provided the olefinic ester (177) by treatment with mesylchloride and triethylamine. Epoxidation followed by elimination led to the previously reported intermediate (146) whose conversion to triptolide (149) has already been described. 

Hydrides from carboxylic acids Carboxylic acids from hydrides Carboxylic acids from hydrides Esters from hydrides Hydrides from aldehydes Hydrides from aldehydes Alkyls from aldehydes Ketones from methylenes Ketones from ketones Alkyls from olefins Acetylenes from halides also acetylenes from acetylenes Esters from alcohols also esters from carboxylic acids Alkyls from olefins Alkyls from olefins... 

A group of substances which are closely associated with the gas hydrates, are the compounds of urea (and thiourea) with a large number of organic substances with long-chain molecules, such as normal saturated hydrocarbons and olefins, alcohols, acids, esters, ketones, halogenated hydrocarbons, etc.3, which were discovered accidentally by Bengen in 1940. These compounds are only produced with unbranched, non-cyclic molecules4. This is even so very specific that a method of separation can be based on it for normal and iso hydrocarbons in mixtures. 

Koch-Haaf earboxylation This acid is much superior to the previously used 95 % H2SO4 for carboxylation of olefins, alcohols, and esters with CO at atmospheric pressure. The beneficial effect appears to be the higher solubility ol CO in this acid. 

The elimination of a molecule of alcohol from an ether has not been developed as a laboratory synthesis of simple olefins, although several olefinic compounds are conveniently made by this method. 1,3 Pentadiene is obtained in 72% yield by passing the ether of 2-penten-4-ol over alumina at 290°. A series of a,yfi-olefinic esters has been made by heating alkyl a-alkoxyisobutyrates with phosphorus pentoxide at 60-100°. The yields range from 85% to 100%. ... 

Studies have been made on the influence of various groups on the rate of hydrogenation of the double bond. Reductions of olefinic alcohols (method 85), olefinic aldehydes (method 161), olefinic ketones (method 196), olefinic acids (method 267), olefinic esters (method 303), olefinic Cyanides (method 394), and olefinic amines (method 460) are treated separately. 

Olefinic alcohols are best prepared by the action of lithium aluminum hydride on the corresponding acid or ester as in the preparation of 3-penten-l-ol (75%). The double bond may be in the a,/S-position to the ester group, The Bouveault-Blanc procedure has also been used with success for reduction of nonconjugated olefinic esters. The addition of the sodium to an alcoholic solution of the ester is superior to the reverse addition of. the ester to sodium in toluene for the preparation of 2,2-dimethyl-3-buten-l-ol (62%). Selective catalytic hydrogenation is inferior. Large amounts of catalyst are required, and the products contain saturated alcohols. ... 

Mild conditions should be employed in alkaline hydrolysis of olefinic esters. Double bonds in many acids migrate readily during saponification. Aqueous alcoholic sodium hydroxide is used in the preparations of 3-ethyl-3-pentenoic acid (56%) and /S-methylcinnamic acid (41%). ... 

In the 1960s, a more promising expansion of the electrodecarboxylation reaction in terms of synthetic utility was recorded in which a carbenium intermediate R" " formed at the anode plays an important role [Eq. (7)] [4]. Depending on the structural characteristics of the carboxylates and/or electrochemical variables, the cation intermediate may undergo the so-called non-Kolbe reactions, for example, substitution, deprotonation, C-C bond cleavage, and rearrangement to provide alcohols, ethers, esters, amides, olefins, and others. 

Conveniently carried out in a hydrocarbon solvent like decallne, this reaction is characterized by a rapid first step, followed by a more difficult elimination (at 200 C) of the second ester molecule it is Important to drive the equilibrium to completion by distillation, and to avoid so coordination of by products to the catalyst. It must also be realized that too high temperatures may further promote formation of Al-O-Al bonds upon elimination of ether (or alcohol + olefin), a detrimental process in terms of solubility and activity. 

Thoria has been used successfully as a catalyst in the synthesis of many organic compounds. Thus both symmetrical and unsymmetrical ketones may be prepared directly from monocarboxylic acids 3 alcohols are converted into ethers or olefines according to the temperature employed benzyl alcohol forms esters with formic, acetic, propionic, isobutyric, and benzoic acids and ammonia and alcohols passed over thoria at 360° yield olefines and primary amines.4... 

A combination of hydrocarbons, alcohols, aldehydes, esters, ethers, or ketones having an olefinic or cycloolefinic type of unsaturation 5% ... 

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