Alkane carboxylic acid derivatives

Propionic acid (CHjCHjCOOH) is used mainly in the food industry, but it is also used for limited purposes in agriculture, in particular for the conservation of fodder-maize. At a concentration as low as 0.1% it inhibits the growth of mould fungi. 

Cyaniminoacetic acid derivatives with new properties were a valuable contribution to the group of fungicides. Of these compounds 2-cyano-N-[(ethylamino)- 

Used at low rates against Peronosporales it has a distinct curative effect, inhibiting disease development in the incubation period (Serres and Carraro, 1976). It ves good control of Plasmopara viticola (Douchet et al 1977), potato and tomato late blight, and hop downy mildew (Absi, 1979). It is most efficacious against early and severe disease infection. 

In the investigation of the mode of action of dialkyl dithiocarbamates, tetramethylthiuram monosulfide (TMTM) revealed a systemic action (Pluijgers and Kerk, 1961 Kaslander, 1966). It is thought that the dimethylthiocarbamoyl part of TMTM is the carrier of the protective effect of the molecule. On this basis, several derivatives with systemic action have been synthesised (Carter et ai, 1963 Banki et al., 1966 Matolcsy and Josepovits, 1967), an example of which is N,N-(dimethylthiocarbamoyl)thioacetic acid (12). 

With these compounds the carrrier of fungitoxicity, the dimethylthiocarbamate ion, could be introduced into the plant, but the antifungal activity of the compound in vitro is low. On the other hand, the compounds show growth-regulating properties similar to those of phenoxyacetic acid derivatives in vivo (Van der Kerk et 

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Simple carboxylic acids derived from open-chain alkanes are systematically named by replacing the terminal -e of the corresponding alkane name with -oic acid. The —C02H carbon atom is numbered Cl. 

Dubois and co-workers (119,410-415) characterized alkyl (R) substituent effects in simple and sterically congested alkanes, alkenes, carboxylic acid derivatives, ketones, amines, alcohols, and so on by the use of topological parameters XR ... 

Flexible aliphatic compounds are also selectively fluorinated. Such substrates may be alkanes, alcohols, carboxylic acid derivatives or ketones as long as the electron-withdrawing group is far enough from the reacting center (Table 2).44 There are differences in yields and reaction rates which are qualitatively easily understood and are directly related to the electron density of the reactive C —H bond. 

In contrast to the carboxylic acid derivatives, nitriles are named as alkane derivatives. To name a nitrile using lUPAC rules ... 

The acyl azide - isocyanate rearrangement is known to proceed stereospecifically with retention of both optical and geometrical (cis-tranSy endo-exo) configuration. Thus, optically active aminocyclopropanes were obtained from optically active cyclopropane carboxylic acid derivatives A lot of exo-amiobicyclo[n.l.O]alkanes or... 

It might therefore be expected that the direct detection of tetrahedral addition intermediates of carboxylic acid derivatives would be most likely with acid halides. There is one report in the literature on the detection of transients during the reaction of acid chlorides with amines in alkane solvents (Entelis and Nesterov, 1963). To observe a tetrahedral intermediate on the reaction path, C—Cl bond breaking would have to be rate-determining. 

An interesting but rather unusual reaction involves the direct carbonylation of carbocations to carboxylic acid derivatives. Carbenium ions can be generated from alkenes or alkanes in strong acidic media. Thus, tertiary carboxylic acids can be produced from C4 or higher alkenes Koch-Haaf reaction) [39] (e.g., eq. (8)). Interestingly, Koch carbonylations are known to be catalyzed by copper or silver cations [40]. 

Alkanoic acid. A carboxylic acid derived from an alkane. 

Generally the esters are warmed together and the alkane thiol driven off. The acids, on the other hand, are condensed in an alkali hydroxide solution and then refluxed with hydrochloric acid to make the ring closure go to completion. This same procedure is followed with the nitriles to hydrolyse the imino group which is formed as an intermediate. These reactions show much similarity to those of a-amino carboxylic acid derivatives with carbon disulfide (compare Section V). Table 32 shows the products which may be prepared by this technique. 

Carboxylic acid derivatives are soluble in solvents such as ethers, chlorinated alkanes, and aromatic hydrocarbons. Like alcohols and ethers, carbonyl compounds with fewer than four carbons are soluble in water. 

Organic aerosols formed by gas-phase photochemical reactions of hydrocarbons, ozone, and nitrogen oxides have been identified in both urban and rural atmospheres (Grosjean, 1977). Most of these species are di- or poly-functionally substituted alkane derivatives. These compounds include aliphatic organic nitrates (Grosjean and Friendlander, 1975), di-carboxylic acids (adipic and glutaric acids) (O Brien et al., 1975), carboxylic acids derived from aromatic hydrocarbons (benzoic and phenylacetic acids), polysubstituted phenols, and nitroaromatics from aromatic hydrocarbons (Kawamuraet al., 1985 Satsumakayashi et al., 1989, 1990). Some species that have been identified in ambient aerosol and are be-... 

Alkanoic acid I lic carboxylic acid derived from an alkane, such as butanoic acid (butyric aciil). 

Why then, is intermediate A not a free alkyl radical In order to examine the reaction pathway of genuine free alkyl radicals under Gif-conditions, they were generated at room temperature by the photolysis of N-hydroxy-2(7//)-thiopyridone derivatives of alkane carboxylic acids and were allowed to react with dioxygen or added trapping reagents (Scheme 2) ... 

Ketenes are most often prepared from carboxylic acid derivatives, and a novel reductive pathway has been described for the conversion of biomass derived fatty acid esters in microalgae oils into hydrocarbons through intermediate ketenes. The conversion into alkanes using Zr02-promoted Ni catalysis is explained as involving conversion of the esters into acids and dehydration to ketenes (observed by strong... 

Direct decarboxylations to alkanes are accomplished on activated carboxylic acid derivatives either thermally or photochemically in the presence of a hydrogen donor. One of the early reagents used for this purpose was lead tetraacetate While primary and secondary carboxylic acids could be readily decarboxylated with moderate success with this reagent, results with tertiary carboxylic acids were unsatisfactory. 

An alternative procedure for reductive decarboxylation without the use of trialkyltin hydrides as hydrogen atom donors has been developed Alkane carboxylic acid esters derived from AT-hydroxypyridine-2-thione decomposed to alkyl radical, which can readily accept a hydrogen atom from t-BuSH (equation 74) to give alkanes. This reaction can be conveniently performed as a one-pot experiment wherein the acid chloride of an alkane carboxylic acid, the sodium salt of thiohydroxamic acid, t-BuSH and 4-dimethyl-aminopyridine (DMAP) in benzene solution are heated to reflux. This procedure works well for COOH groups attached to primary and secondary carbon atoms. Instead of AT-hydroxypyridine-2-thione, one can use other thiohydroxamic acids, viz. iV-hydroxy-AT-methylthiobenzamide, 3-hydroxy-4-methylthiazole-2(3if)-thione (equation 75) and l-iV-hydroxy-3-AT-methylbenzoylenethiourea for decarboxylation reactions. 

It is apparent from the above general mechanism (eqs. 62-64) that any compound able to produce carbocations can be carboxylated. Consequently, not only alkenes but also other hydrocarbons (alkanes, dienes) and alcohols are able to react with carbon monoxide. Furthermore, the intermediate can be quenched by other proton sources such as alcohols, amines, and acids to form carboxylic acid derivatives. 

Poly(cu-(3-thienyl)alkane- 3.2 Carboxylic acid derivatives. . . 848... 

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