Aliphatic esters table

Acid Chlorides and Acid Anhydrides of Aromatic Adda, Table IV, 187. Aliphatic Esters, Table III, 106. 

This method for preparing 2-phenyl-1-pyrroline, and assorted 2-substituted 1-pyrrolines, is one of the best currently available, particularly because it reproducibly affords clean materials. Generally, the procedure is amenable to various aromatic esters 2 it has also been applied successfully to aliphatic esters (Table I).3 An advantage of this method is the use of readily available, inexpensive N-vinyl-pyrrolidin-2-one as a key starting material. This compound serves effectively as a 3-aminopropyl carbanion equivalent. The method illustrated in this procedure has been extended to include the synthesis of 2,3-disubstituted pyrrolines. Thus, alkylation of the enolate of the intermediate keto lactam, followed by hydrolysis, leads to various disubstituted pyrrolines in good yields (see Table II).3... 

N-Benzylamides are recommended when the corresponding acid is liquid and/or water-soluble so that it cannot itself serve as a derivative. Phe benzylamides derived from the simple fatty acids or their esters are not altogether satisfactory (see Table below) those derived from most hydroxy-acids and from poly basic acids or their esters are formed in good yield and are easily purified. The esters of aromatic acids yield satisfactory derivatives but the method must compete with the equally simple process of hydrolysis and precipitation of the free acid, an obvious derivative when the acid is a solid. The procedure fails with esters of keto, sul phonic, inorganic and some halogenated aliphatic esters. 

There have been numerous studies on the kinetics of decomposition of A IRK. AIBMe and other dialkyldiazenes.46 Solvent effects on are small by conventional standards but, nonetheless, significant. Data for AIBMe is presented in Table 3.3. The data come from a variety of sources and can be seen to increase in the series where the solvent is aliphatic < ester (including MMA) < aromatic (including styrene) < alcohol. There is a factor of two difference between kA in methanol and k< in ethyl acetate. The value of kA for AIBN is also reported to be higher in aromatic than in hydrocarbon solvents and to increase with the dielectric constant of the medium.31 79 80 Tlic kA of AIBMe and AIBN show no direct correlation with solvent viscosity (see also 3.3.1.1.3), which is consistent with the reaction being irreversible (Le. no cage return). 

Dihydroepistephamiersine 6-acetate (7) was isolated from Stephania abyssinica as a homogeneous oil. The UV spectrum showed an absorption maximum at 286 nm, and the IR spectrum exhibited a band corresponding to an aliphatic ester carbonyl group at 1725 cm-1 (20). The H-NMR data are summarized in Table II. In chemical investigations, hydrolysis of 7 with barium methoxide gave an alcohol identical with 6-dihydroepistephamiersine (17), which on further treatment with mineral acid gave the known alkaloid, stephasunoline (17). Thus structure 7 was proposed for 6-dihydroepistephamiersine 6-acetate (20). 

A molecule of aliphatic ester possesses two substituents around the ester group —C(0)0—, namely, alcohol and acid residues. Ester group decreases the BDE of a-C—H bonds in both substituents alcoholic and acidic. Therefore, an ester molecule has two different types of weak C—H bonds that are attacked by peroxyl radicals a-C—H bonds of the alcohol substituent —CH20C(0)R and the a-C—H bonds of the acid substituent —CH2C(0)0R. The values of BDE of these types of C—H bonds are close but not the same. The values of BDE of the C—H bonds are collected in Table 9.10. 

The initial study of the La3 +-catalyzed methanolysis of carboxylate esters163 reported the apparent second-order rate constant for La2 + ( OCH3)2-catalyzed methanolysis of some representative examples of aryl esters (2, 5 and 2,4-dinitrophenyl acetate (14)), phenyl benzoate (15) and three aliphatic esters, ethyl acetate, isopropyl acetate (16) and tert-butyl acetate (17). Given in Table 6 are the rate constants for the La3+ and methoxide-catalyzed methanolysis of these esters along with... 

In the soap, perfume, and flavor industries benzyl alcohol is primarily used in the form of its aliphatic esters. Benzyl benzoate [120-51 A] finds widespread use as a fragrance diluent. Benzyl alcohol is frequently employed in bar soap fragrances at 30—40 wt % of the fragrance. Benzyl alcohol is commercially available in five grades (Table 2). 

Support-bound primary or secondary aliphatic alcohols can be acylated under conditions similar to those used in solution, provided that these conditions are compatible with the chosen linker. For instance, acids can be activated with a carbodiimide either as symmetric anhydrides or as O-acylisoureas, which quickly react with alcohols in the presence of a catalyst, such as DMAP or another base, to yield esters (Table 13.12). Further acid derivatives suitable for esterification reactions on solid phase include acyl halides and imidazolides. HOBt esters react only slowly with alcohols, but enable the selective acylation of primary alcohols in the presence of secondary alcohols (Entry 5, Table 13.12). 

In the 1950s Taft devised a method of extending linear free-energy relationships to aliphatic systems.16 He suggested that, since the electronic nature of substituents has little effect on the rate of acid-catalyzed hydrolysis of meta- or para-substituted benzoates (p values are near 0, see Table 2.3), the electronic nature of substituents will also have littie effect on acid-catalyzed hydrolysis of aliphatic esters. All rate changes due to substituents in the latter reactions are, therefore, probably due to steric factors.17 Taft defined Es, a steric substituent constant, by Equation 2.16... 

Table 10.25 Aliphatic esters It is considered that the table will be of greatest use if the esters are subdivided under the various acids rather than arranged in order of increasing b.p. or m.p. irrespective of the nature of the carboxylic acid. The latter procedure leads to an unwieldy, heterogeneous table which has relatively little pedagogic or, indeed, practical value. ...

Organic chemicals that are susceptible to oxidation and are of concern from the perspective of contamination and environmental degradation include aliphatic and aromatic hydrocarbons, alcohols, aldehydes, and ketones phenols, polyphenols, and hydroquinones sulfides (thiols) and sulfoxides nitriles, amines, and diamines nitrogen and sulfur heterocyclic compounds mono- and di-halogenated aliphatics linear alkybenzene-sulfonate and nonylphenol polyethoxylate surfactants and thiophosphate esters. Table... 

Long chain aliphatic esters, commonly called waxes, are components of epicuticular waxes of the olive fruits (Bianchi and Vlahov, 1994). Whilst in virgin olive oils the wax concentration is negligible, in olive-residue oil the wax content is considerable. Thus, the presence of long chain esters in olive oil is evidence of the presence of solvent extracted olive oil, also commonly called sansa olive oil. The detection and quantification of waxes in olive oil is an official method. As shown in Table 2.2, virgin olive oils fit for consumption must contain less than 250 mg/kg of waxes the limits are 350 mg/kg for categories 4,5 and 6, whilst for olive-residue oil the amount is expected to be over 350 mg/kg. 

The effect noted earlier that aromatic esters are subject to larger rate accelerations in DMSO, as evident from Tables 14 and 15, can now be explained. The transition state anion in the case of an aromatic ester will be more polarizable than that for an aliphatic ester. Moreover, the phenyl ring attached to the carbonyl group acts... 

---