Alcohols carbonic acid esters

The reaction of phosgene (carbonic dichloride [75-44-5]) with alcohols gives two classes of compounds, carbonic esters and carbonochloridic esters, commonly referred to as carbonates and chloroformates. The carbonic acid esters (carbonates), R0C(0)0R, are the diesters of carbonic acid [463-79-6]. The carbonochloridic esters, also referred to as chloroformates or chlorocarbonates, C1C(0)0R, are esters of hypothetical chloroformic acid [463-73-0] CICOOH. 

Carbonic acid esters (alkoxycarbonyl derivatives) are diesters of general formula R-O-CO-O-R. A single mechanism operates in the HO -catalyzed (and presumably also in the enzyme-catalyzed) hydrolysis of carbonic acid esters, namely a rate-determining addition of the base to the carbonyl C-atom to form an intermediate whose breakdown yields the drug (ROH), C02, and an alcohol (R OH) (Fig. 8.7,a) [153],... 

Examples of the cleavage of support-bound carbonates are given in Table 3.36. Depending on the structure of the carbonate, acidolytic, base-induced, nucleophilic, or photolytic cleavage can be used to release the alcohol. Acidolysis of the benzylic C-O bond of resin-bound benzyl carbonates leads to the release of an unstable carbonic acid ester, which undergoes decarboxylation to yield the alcohol. 

The reaction of alcohols, carbon monoxide, and oxygen in the presence of selenium oxide, nitrogen, and DBU under pressure gave carbonic acid esters (79JAP(K)121720). 

In the second step, a mixed carbonic acid ester is formed from the carbonic acid ester chloride and the alcohol moiety formed in the first step. 

In the proposed vapor phase processes for organic acid synthesis, carbon monoxide is passed with the vaporized aliphatic alcohol over catalysts similar in nature to those employed in the pressure synthesis of higher alcohols from hydrogen-carbon monoxide mixtures. Pressures on the order of 200 atmospheres are employed. Temperatures of about 200° to 300° C. are preferred but it is necessary to use somewhat higher ones in order to obtain sufficient reaction. Mixtures of the oxides of zinc and chromium or copper, promoted with alkali or alkaline earth oxides, are suitable catalysts for the formation of carbon-carbon linkages.97 Catalysts composed of an alkali, chromium, and molybdenum have been claimed for the synthesis of mixtures of higher alcohols, aldehydes, acids, esters, etc., from carbon monoxide and vaporized aliphatic alcohols as methanol, ethanol, etc., at temperatures of about 420° C. and a pressure of 200 atmospheres.98... 

Unsaturated fatty alcohols can also be epoxidized by lipase-catalyzed perhydrol-ysis (16). Interestingly, the outcome of the reaction depends on the ester applied for peroxy acid generation (Fig. 5). Fatty acid esters such as butyric acid ethylester react to epoxyalkanolacylates in a three-step one-pot reaction. Carbonic acid esters such as diethyl carbonate also form peroxy acids (percarbonic acid derivatives) and epox-idize the unsaturated alcohol however, in a water-containing environment, they are obviously not stable enough to esterify the hydroxyl group. Thus, the end product is the epoxy alcohol. 

Urethans from alcohols via carbonic acid esters... 

A polemic has developed in Russia on the formation and importance of the carbonic acid ester diethylpyrocarbonate in sparkling wines. Parfent ev and Kovalenko (1951, 1952) refuted Rosenfeld s (1952) concept that diethylcarbonate is only condensed carbon dioxide in alcohol. They note that it has been synthesized and its physical properties determined. Kozenko (1952) reported the amount of carbonic acid ester to be 0 in musts and to increase during fermentation. In still wines about 9 mg. per liter were found, whereas in sparkling wines 125 mg. per liter were noted. In a bottled sparkling wine 53 mg. were reported before opening, 42 mg. at 18 days after opening, 32 at 60 days, and 26 at 90 days after opening. The subject is, however, by no means settled see, for example, Merzhanian (1951, 1952). 

Amorphous Se added to a soln. of -butylamine in tetrahydrofuran, CO introduced, after ca. 5 min. when the Se has dissolved oxygen or air introduced simultaneously with CO for 4 hrs., then the CO-flow stopped and the Og-flow continued to precipitate Se -> l,3-di- -butylurea. Y ca. 100%. F. e., also 2-imidazolidone from ethylenediamine (cf. Synth. Meth. 3, 375), s. N. Sonoda et al.. Am. Soc. 93, 6344 (1971) sym. carbonic acid esters from alcohols in the presence of Na-alkoxide s. Tetrah. Let. 7977,4885 urethans from alcohols, amines, and CO s. Chem. Lett. 1972, 373 (Eng) carbonylation of amines in the presence of Ag-acetate, sym. ureas from prim, amines and sym. oxamides from sec. amines, s. T. Tsuda, Y. Isegawa, and T. Saegusa, J. Org. Chem. 37, 2670 (1972). 

These adducts represent much more reactive intermediaries than the initial chlo-roformates. Their reactions with alcohols and glycols form carbonic acid esters and amine chlorohydrates through the following reaction ... 

Poly(W-pyiTOlidonylethylene), Poly((V-vinylpyrrolidone) (solubility depending on small amounts of W) acetone, dil. acids, aromatic alcohols, chloroacetic acid esters, chloroform, chlorohydrins, ethanol, glacial acetic acid, methanol, nitromethane, pyridine Acetic esters, acetone, acid 1 esters, carbon tetrachloride, 1 -chlorotoluene, diethyl ether, hydrocarbons, methoxybutyrate esters, nitomethaneAV 1-6,13,30... 

Esters can participate m hydrogen bonds with substances that contain hydroxyl groups (water alcohols carboxylic acids) This confers some measure of water solubil ity on low molecular weight esters methyl acetate for example dissolves m water to the extent of 33 g/100 mL Water solubility decreases as the carbon content of the ester increases Fats and oils the glycerol esters of long chain carboxylic acids are practically insoluble m water... 

Ahyl alcohol undergoes reactions typical of saturated, aUphatic alcohols. Ahyl compounds derived from ahyl alcohol and used industriahy, are widely manufactured by these reactions. For example, reactions of ahyl alcohol with acid anhydrides, esters, and acid chlorides yield ahyl esters, such as diahyl phthalates and ahyl methacrylate reaction with chloroformate yields carbonates, such as diethylene glycol bis(ahyl carbonate) addition of ahyl alcohol to epoxy groups yields products used to produce ahyl glycidyl ether (33,34). 

Telomerization Reactions. Butadiene can react readily with a number of chain-transfer agents to undergo telomerization reactions. The more often studied reagents are carbon dioxide (167—178), water (179—181), ammonia (182), alcohols (183—185), amines (186), acetic acid (187), water and CO2 (188), ammonia and CO2 (189), epoxide and CO2 (190), mercaptans (191), and other systems (171). These reactions have been widely studied and used in making unsaturated lactones, alcohols, amines, ethers, esters, and many other compounds. 

The reaction proceeds in stages, first producing a carbonochloridic ester (chloroformate), and then a carbonic acid diester (carbonate). When a different alcohol is used for the second stage, a mixed radical or unsymmetrical carbonate is produced. 

With Alcohols, Ethers, and Esters. Carbon monoxide reacts with alcohols, ethers, and esters to give carboxyHc acids. The reaction yielding carboxyHc acids is general for alkyl (53) and aryl alcohols (54). It is cataly2ed by rhodium or cobalt in the presence of iodide and provides the basis for a commercial process to acetic acid. 

Esterification. The esterification of rosin provides important commercial products for the adhesive industry. Rosin esters are formed by the reaction of rosins with alcohols at elevated temperatures. Because the carboxyl group of the resin acids is hindered by attachment to a tertiary carbon, esterification with an alcohol can only be accomplished at elevated temperatures. This hindrance is in turn responsible for the high resistance of the resin acid ester linkage to cleavage by water, acid and alkali. 

Because of thetr electron deficient nature, fluoroolefms are often nucleophihcally attacked by alcohols and alkoxides Ethers are commonly produced by these addition and addition-elimination reactions The wide availability of alcohols and fliioroolefins has established the generality of the nucleophilic addition reactions The mechanism of the addition reaction is generally believed to proceed by attack at a vinylic carbon to produce an intermediate fluorocarbanion as the rate-determining slow step The intermediate carbanion may react with a proton source to yield the saturated addition product Alternatively, the intermediate carbanion may, by elimination of P-halogen, lead to an unsaturated ether, often an enol or vinylic ether These addition and addition-elimination reactions have been previously reviewed [1, 2] The intermediate carbanions resulting from nucleophilic attack on fluoroolefins have also been trapped in situ with carbon dioxide, carbonates, and esters of fluorinated acids [3, 4, 5] (equations 1 and 2)... 

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