2- alkanoic acids

Although these are rather unusual substrates, their degradation by anaerobic bacteria has been 

Glycolate or fumarate is fermented by an organism belonging to the family Lachnospi-raceae to acetate, succinate, and COj without the formation of hydrogen (Janssen and Hugenholtz 2003). 

The aerobic degradation of these has been covered in the discussion on alkanes and need not be 

The oxidation of acetate under anaerobic conditions can take place by different pathways, both of which have been investigated in detail and their enzymology delineated (Thauer et al. 1989). 

Oxidation may take place by a modified tricarboxylic acid cycle in which the production of CO2 is coupled to the synthesis of NADPH and reduced ferredoxin, and the dehydrogenation of succinate to fumarate is coupled to the synthesis of reduced menaquinone. This pathway is used, for example, by Desulfuromonas acetoxidans and in modified form by 

Name of Compound Plant Source Order References Comments 

Fatty acids ( -Alkanoic) Tetradecanoic acid Hexadecanoic acid 

Docosanoic acid Tetracosanoic acid Triacontanoic acid Tetracontanoic acid 

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The tendency to form organized monolayers improves with chain length. This is illustrated in a study of adsorption kinetics in alkanoic acid monolayers on alumina by Chen and Frank [36]. They find that the Langmuir kinetic equation, discussed in Section XVII-3, (see Problem XI-6)... 

Fig. XI-1. Adsorption kinetics for C g alkanoic acids adsorbing onto alumina for various solution concentrations from Ref. 36. Lines are the fit to Eq. XI-IS.

Allara D L and Nuzzo R G 1985 Spontaneously organized molecular assemblies. 1. Formation, dynamics, and physical-properties of normal-alkanoic acids adsorbed from solution on an oxidized aluminum surface Langmuir 1 45-52... 

TABl.E 11-10. THIAZOt E CARBOXYLIC. THIAZOLE ALKANOIC ACIDS, AND THEIR DERIVATIVES (10)... 

Thiazole acetic acids and their hotnologs can also be prepared by cyclization procedures 4-thiazole alkanoic acids and their salts were prepared by treating a thioamide with a -y-chloro- or 7-bromoacetoacetic or their a-alkyl derivatives (4, 10, 16, 22, 273, 275, 281, 640, 647, 695). 

Similarly, 5-thiazole alkanoic acids and their salts are obtained from thioamides and /3-halo -y-keto acids (695). Thus thioarylamides condensed with 3-aroyl-3-bromopropionic acid (88) in isopropanolic solution in the presence of Na COs give first 4-hydroxy-2-aryl-A-2-thiazoline-5-acetic acid intermediates (89), which were dehydrated in toluene with catalytic amounts of p-toluene sulfonic acid to 2,4-diaryl-5-thiazole acetic acid (90) (Scheme 39) (657), with R = H or Me Ar = Ph, o-, m- or p-tolyl, o-, m-, or P-CIC6H4, 0-, m-, or p-MeOC(iH4, P-CF3C6H4, a-thienyl, a-naphthyl (657). 

Alkannin [577-88-4 Alkanoic acids Alkanolanudes N-Alkanolanudes Alkanolanunes... 

The anhydride can be made by the Hquid-phase oxidation of acenaphthene [83-32-9] with chromic acid in aqueous sulfuric acid or acetic acid (93). A postoxidation of the cmde oxidation product with hydrogen peroxide or an alkaU hypochlorite is advantageous (94). An alternative Hquid-phase oxidation process involves the reaction of acenaphthene, molten or in alkanoic acid solvent, with oxygen or acid at ca 70—200°C in the presence of Mn resinate or stearate or Co or Mn salts and a bromide. Addition of an aHphatic anhydride accelerates the oxidation (95). 

Methylpyrazole has been investigated as a possible treatment for alcoholism. The stmcture—activity relationship (SAR) associated with a series of pyrazoles has been examined ia a 1992 study (51). These compounds were designed as nonprostanoid prostacyclin mimetics to inhibit human platelet aggregation. In this study, 3,4,5-triphenylpyrazole was linked to a number of alkanoic acids, esters, and amides. From the many compounds synthesized, triphenyl-IJT-pyrazole-l-nonanoic acid (80) was found to be the most efficacious candidate (IC g = 0.4 //M). 

Table 1. Physical Properties of the Straight-Chain Alkanoic Acids, C H2 02...

Melting points, boiling points, densities, and refractive indexes for carboxyUc acids vary widely depending on molecular weight, stmcture, and the presence of unsaturation or other functional groups (Tables 1,2,3, and 5). In addition, some useful constants for alkanoic acids are Hsted in Table 1. Some constants for selected unsaturated and substituted acids are given in Table 7. 

Heats of combustion for liquid alkanoic acids at 25°C are given by the equation (5) ... 

The long-chain alkanoic acids and their derivatives are polymorphic with the unit cell containing dimers formed by hydrogen bonding between carboxyl groups. 

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 ... 

Table 8. Solubilities of Alkanoic Acids in Water and Organic Solvents...

Formic acid is the most acidic straight-chain alkanoic acid. SolubiUty in water of alkanoic acids containing more than nine carbon atoms is too low... 

Table 10. Dissociation Constant for Straight-Chain and Chlorinated Alkanoic Acids at 25°C ...

The alkanoic acids, with the exception of formic acid, undergo typical reactions of the carboxyl group. Formic acid has reducing properties and does not form an acid chloride or an anhydride. The hydrocarbon chain of alkanoic acids undergoes the usual reactions of hydrocarbons except that the carboxyl group exerts considerable influence on the site and ease of reaction. The alkenoic acids in which the double bond is not conjugated with the carboxyl group show typical reactions of internal olefins. All three types of reactions are industrially important. 

Reactions of the hydrocarbon chain in alkanoic acids include a-sulfonation and halogenation (51—54). The a-sulfonated fatty ester salts have excellent lime-dispersing properties and are valuable surface-active agents. 

Alkanes, dipurin-8-yl-synthesis, 5, 574 Alkanes, poly-N-pyrazoIyl-synthesis, 5, 320 Alkanoic acids, tetrazolyl-anti-inflammatory activity, 5, 835 Alkanoic acids, 4-thienyi-cyclization, 4, 905-906 Alkene metathesis mechanism, 1, 668 Alkenes activated... 

Tnfluoroacetic anhydride is a good reagent for various cychzations In the presence of a catalytic amount of phosphonc acid, it is used for the macrocyclization of oi-(2-thienyl)alkanoic acids [48] (equation 21)... 

Another method of preparing ,to-diarylated alkanoic acids utilizes the condensation of 5-(w-phenylalkyl) substituted 2-thiophenealde-hydes (224) with benzyl cyanides and hydrolysis and desulfurization of the acids obtained (225). In this way, a,o-diphenylcaprylic acid has been prepared. ... 

Upon heating of a carboxylic ester 1 with sodium in an inert solvent, a condensation reaction can take place to yield a a-hydroxy ketone 2 after hydrolytic workup. " This reaction is called Acyloin condensation, named after the products thus obtained. It works well with alkanoic acid esters. For the synthesis of the corresponding products with aryl substituents (R = aryl), the Benzoin condensation of aromatic aldehydes is usually applied. 

The study of biochemical natural products has also been aided through the application of two-dimensional GC. In many studies, it has been observed that volatile organic compounds from plants (for example, in fruits) show species-specific distributions in chiral abundances. Observations have shown that related species produce similar compounds, but at differing ratios, and the study of such distributions yields information on speciation and plant genetics. In particular, the determination of hydroxyl fatty acid adducts produced from bacterial processes has been a successful application. In the reported applications, enantiomeric determination of polyhydroxyl alkanoic acids extracted from intracellular regions has been enabled (45). 

The reaction of ct-nitrocycloalkanones v/ith an aqneons solution of formaldehyde in the presence of potassium carbonate affords 2-nitro-l,3-diol-Oj-alkanoic acids fEq 5 21 ... 

In Table 9.10 we have listed some examples of substrates, products and organisms that have been dted in the patent literature for the production of various alkanols, alkanoic acids, ketones and dioic adds. These are meant to act as illustrations, we would not expect you to remember them all. 

A solution of 1 mmol of the 4,5-dihydro-2-(2-hydroxyalkyl)-4.4-dimethyloxazole (4) in 8 mL of 3 N sulfuric acid and is stirred at 80 °C. for 1.5 h. The mixture is cooled to 20 °C and extracted with five 10-mL portions of Et20. The combined organic phase is dried with Na2S04 and concentrated in vacuo to give the 3-hydroxy-alkanoic acid in quantitative yield and in good purity. The known acids are identified by a comparison of physical and spectral data with those of authentic samples. 

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