Butyric acid, 288 Table

It IS hard to find a class of compounds in which the common names of its members have influenced organic nomenclature more than carboxylic acids Not only are the common names of carboxylic acids themselves abundant and widely used but the names of many other compounds are derived from them Benzene took its name from benzoic acid and propane from propionic acid not the other way around The name butane comes from butyric acid present m rancid butter The common names of most aldehydes are derived from the common names of carboxylic acids—valeraldehyde from valeric acid for exam pie Many carboxylic acids are better known by common names than by their systematic ones and the framers of the lUPAC rules have taken a liberal view toward accepting these common names as permissible alternatives to the systematic ones Table 19 1 lists both common and systematic names for a number of important carboxylic acids... 

The common method of naming aldehydes corresponds very closely to that of the related acids (see Carboxylic acids), in that the term aldehyde is added to the base name of the acid. For example, formaldehyde (qv) comes from formic acid, acetaldehyde (qv) from acetic acid, and butyraldehyde (qv) from butyric acid. If the compound contains more than two aldehyde groups, or is cycHc, the name is formed using carbaldehyde to indicate the functionaUty. The lUPAC system of aldehyde nomenclature drops the final e from the name of the parent acycHc hydrocarbon and adds al If two aldehyde functional groups are present, the suffix -dialis used. The prefix formjlis used with polyfunctional compounds. Examples of nomenclature types are shown in Table 1. 

Formic, acetic, propionic, and butyric acids are miscible with water at room temperature. SolubiUty in water decreases rapidly for the higher alkanoic acids as the chain length increases (Table 8) (19). The solubiUty in water at pH 2—3 for unionized acids is given by the following relationship ... 

Resolution of racemic alcohols by acylation (Table 6) is as popular as that by hydrolysis. Because of the simplicity of reactions ia nonaqueous media, acylation routes are often preferred. As ia hydrolytic reactions, selectivity of esterification may depend on the stmcture of the acylatiag agent. Whereas Candida glindracea Upase-catalyzed acylation of racemic-cx-methylhenzyl alcohol [98-85-1] (59) with butyric acid has an enantiomeric value E of 20, acylation with dodecanoic acid increases the E value to 46 (16). Not only acids but also anhydrides are used as acylatiag agents. Pseudomonasfl. Upase (PFL), for example, catalyzed acylation of a-phenethanol [98-85-1] (59) with acetic anhydride ia 42% yield and 92% selectivity (74). 

A very interesting steric effect is shown by the data in Table 7-12 on the rate of acid-catalyzed esterification of aliphatic carboxylic acids. The dissociation constants of these acids are all of the order 1(T, the small variations presumably being caused by minor differences in polar effects. The variations in esterification rates for these acids are quite large, however, so that polar effects are not responsible. Steric effects are, therefore, implicated indeed, this argument and these data were used to obtain the Es steric constants. Newman has drawn attention to the conformational role of the acyl group in limiting access to the carboxyl carbon. He represents maximum steric hindrance to attack as arising from a coiled conformation, shown for M-butyric acid in 5. 

Neurotransmitter Transporters. Table 2 SLC6 family transporters for GABA (y-amino butyric acid) and glycine... 

The reaction conditions, normally applied, are those described in chap. 2 for the radical pathway. These are a platinum anode, high current densities, no additives and a slightly acidic medium. However, the dimerizations shown in Table 2, No. 2, also gave in some cases good yields at a carbon anode in acetonitrile-water [52] or at a baked carbon anode in methanol [48]. With propionic and butyric acid an unusually high portion of alkene is formed at the cost of the dimer. 

The Monod kinetic parametos were evaluated by least squares fitting procedures, for tiie single and multiple substrate systems with/without mutual inhibition, and were indicated in Table 1 [6]. The value of indicates the linear decomposition rate. It is dear that the decomposition rate for prc iionic acid is significantly lower than those for acetic add and butyric acid. 

Ito et al.40 examined the electrochemical reduction of C02 in dimethylsulfoxide (DMSO) with tetraalkylammonium salts at Pb, In, Zn, and Sn under high C02 pressures. At a Pb electrode, the main product was oxalic acid with additional products such as tartaric, malonic, glycolic, propionic, and n-butyric acids, while at In, Zn, and Sn electrodes, the yields of these products were very low (Table 3), and carbon monoxide was verified to be the main product even at a Pt electrode, CO was mainly produced in nonaqueous solvents such as acetonitrile and DMF.41 Also, the products in propylene carbonate42 were oxalic acid at Pb, CO at Sn and In, and substantial amounts of oxalic acid, glyoxylic acid, and CO at Zn, indicating again that the reduction products of C02 depend on the electrode materials used. 

Deuteration studies with acetic acid-d4 (99.5% atom D) as the carboxylic acid building block, ruthenium(IV) oxide plus methyl iodide-d3 as catalyst couple and 1/1 (C0/H2) syngas, were less definitive (see Table III). Typical samples of propionic and butyric acid products, isolated by distillation in vacuo and glc trapping, and analyzed by NMR, indicated considerable scrambling had occurred within the time frame of the acid homologation reaction. 

Gaseous alkanes such as methane, ethane, and propane were also carboxylated to give acetic, propionic, and butyric acids, respectively, as shown in Table 3 102,103,103a Ethane and propane were best carboxylated by the mixed catalyst of Pd(OAc)2 and Cu(OAc)2, while methane was not effectively carboxylated by the same catalytic system. In the case of methane, Cu(OAc)2 gave the best result among the catalysts employed. However, the yield of acetic acid based on methane is low (Equation (78)). 

Table VI compares results from air, dust and slurry investigations on VFA and phenolic/indolic compounds in piggeries. Relative values are used. When comparing the results derived from investigations on dust, air or slurry it is necessary to use relative values because of the different dimensions, for experience shows that in spite of large quantitative differences between two samples within the group of carboxylic acids and within the group of phenolic/indolic compounds the proportions of the components remain rather stable (36). In the group of VFA acetic acid is the main component in air, dust, and slurry followed by propionic and butyric acid. The other three acids amount to less than 25%. In the group of phenols/ indoles p-cresol is the main component in the four cited investigations. However, it seems that straw bedding can reduce the p-cresol content in this case phenol is the main component, instead (37).

The investigations of dust from piggeries show that both VFA and phenols/indoles are present in a considerable amount. However, compared to the air-borne emissions calculated on the base of the results of LOGTENBERG and STORK (38) less than the tenth part (1/10) of phenols/indoles and about the hundredth part (1/100) of VFA are emitted by the dust, only. Table VII compares the dust-borne and air-borne emissions of VFA and phenols from piggeries. The total amounts are given in addition to the amounts of butyric acid and p-cresol which are both known as intensively smelling compounds. The recognition odour threshold values of these two components are included, as well. Under the assumption of a dust concentration of 10 mg/m3 (7) one cubic meter of air... 

Table VII Amounts of volatile fatty acids and phenolic/indolic compounds emitted from piggeries by dust and air, respectively. The recognition odour thresholds for butyric acid and p-cresol are included. 1)=HARTUNG (34), 2) =LOGTENBERG and STORK (38), 3)=CORMACK et al. (42), 4) =LEONARDOS et al. (43).

Schuster et al. reported work on monitoring a complex ace-tone-butanol-ethanol (ABE) fermentation system.22 They looked at the qualitative nature of the biomass as well as the solvents present in the liquid phase. A hierarchical cluster analysis was performed on samples from various times of the fermentation. The clusters were then classified using classical markers and analyses. The resultant table, combining qualitative interpretation and quantitative results, shows an interesting mosaic of the system over time. Total solvents, optical density, and butyric acid are given as numeric values in either absorbance units of g/1. 

HCIO4 perchloric acid, DOPA butyric acid. Other abbreviations (- )-3-(3,4-Dihydroxyphenyl-L-alanine, see Table 5. GABA y-amino... 

In carbon-13 NMR, the presence of the oxygen also influences the chemical shift of the carbon atoms. Table 9-4 shows the chemical shifts of the Ccirbonyl carbon atom for several classes. This can also be seen in the NMR spectrum of butyric acid in Figure 9-19. 

In search of a convenient procedure for preparing diazo substrates for the cycloaddition to Cgg, Wudl introduced the base-induced decomposition of tosyl-hydrazones [116]. This procedure allows the in situ generation of the diazo compoimd without the requirement of its purification prior to addition to Cgg. Since they are rapidly trapped by the fullerene, even unstable diazo compounds can be successfully used in the 1,3-dipolar cycloaddition. In a one-pot reaction the tosyUiydrazone is converted into its anion with bases such as sodium methoxide or butylHfhium, which after decomposition readily adds to Cgg (at about 70 °C). This method was first proven to be successful with substrate 142. Some more reactions that indicate the versatility of this procedure are shown in Table 4.4. Reaction of 142 with CgQ under the previously described conditions and subsequent deprotection of the tert-butyl ester leads to [6,6]-phenyl-C5j-butyric acid (PCBA) that can easily be functionalized by esterification or amide-formation [116]. PCBA was used to obtain the already described binaphthyl-dimer (obtained from 149 by twofold addition) in a DCC-coupling reaction [122]. 

As the loading of STA on the catalyst support is decreased, incomplete anhydride conversion is observed and significant hydrolysis of the anhydride to form iso-butyric acid is observed (Table 2). Use of silica supported phosphoric acid results in lower ketone yields and significant hydrolysis of the iso-butyric anhydride. Blank reactions (catalyst and anhydride, 90°C, 30 min) indicates that hydrolysis of anhydride is observed in the presence of these catalysts and may result from either dehydroxylation of the silica support or residual water in the catalyst, ffowever this reaction is slow (42%STA/silica, 44% conversion and 70%P[3PO4/silica, 86% conversion respectively). 

Table .2 Examples of ester production rates and acid conversions achieved for different optimized syntheses of formic, acetic, propionic, butyric, and iso-butyric acid alkyl esters.

The solvent acid also affects the oxidation rate since the rate with cobalt acetate (Table II) is reduced in propionic or butyric acids in contrast to the increase in the hydroperoxide decomposition rate. 

About half of the NPN of milk is accounted for by urea. Orotic acid is a particular hallmark of the milks of ruminants milks of other species contain little if any of it (Larson and Hegarty 1977). The free amino acids constituting the a-amino N fraction in Table 1.6 include those that are also found in proteins, as well as ornithine, citrulline, and cx-amino butyric acid. Quantitative analyses of the mixture of free amino acids have been published (Deutsch and Samuelsson 1958 Armstrong and Yates 1963 Rassin et al. 1978). 

Alkyl carbon atoms attached in a position a, / , or y to a carboxy function give rise to tx, [1. and y effects which shift the carboxy carbon resonances by 10, 4 and — 1 ppm, respectively. This trend is illustrated by the 13C shift values collected for formic, acetic, propionic, and butyric acids among others in Table 4.34 [305-309], Further, carboxy carbons of x halo acids and dicarboxylic acids with closely spaced carboxy groups arc shielded relative to those of parent alkanoic acids (Table 4.34). On the other hand, the x, j3 and y carboxy increments Z, = hi(RCOon)- — krh) f°r the carbon shifts of an alkyl chain are... 

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