Carboxylic acid alicyclic

Aldonic acid (Section 25 19) Carboxylic acid obtained by oxi dation of the aldehyde function of an aldose Aldose (Section 25 1) Carbohydrate that contains an aldehyde carbonyl group in its open chain form Alicyclic (Section 2 15) Term describing an a/iphatic cyclic structural unit... 

Changing the functionality on the alicyclic ring from an amine to a carboxylic acid leads to a compound that shows antiallergic activity, acting possibly by means of inhibition of the release of allergic mediators. Thus, condensation of acylated indole with cyclohexanone carboxylic acid affords directly oxarbazole (29). ... 

Charton s at value for S02Me merits comment in that it is based not on the behavior of aliphatic or alicyclic carboxylic acids but on the pKa values of 4-substituted quin-uclidinium ions 30 in water. This system has been advocated by Grob and Schlageter171 as... 

The effect of C ,C -disubstituted amino acids (aaAAs) on peptide secondary structure has been studied in recent years.2a d While longer side-chain C ,C -di-n-alkyl amino acids promote extended peptide conformation,23 alicyclic aaAAs, in which the Ca carbon forms a cyclic bridge with itself, such a 1-aminocyclopentane-l-carboxylic acid (Ac5c) and 1-aminocyclohexane-l-carboxylic acid (Ac6c), have helix-forming characteristics similar to those of 1 -aminoisobutyric acid (Aib).2ax... 

Non-Kolbe electrolysis of alicyclic p-hydroxy carboxylic acids offers interesting applications for the one-carbon ring extension of cyclic ketones (Eq. 35) [242c]. The starting compounds are easily available by Reformatsky reaction with cyclic ketones. Some examples are summarized in Table 13. Dimethylformamide as solvent and graphite as anode material appear to be optimal for this reaction. 

Rule of thumb The stability of molecular ions roughly decreases in the following order aromatic compounds > conjugated alkenes > alkenes > alicyclic compounds > carbonyl compounds > linear alkanes > ethers > esters > amines > carboxylic acids > alcohols > branched alkanes. [81]... 

Alicyclic 2-isocyanato-l-carboxylic acids 214 synthesized from alicyclic trimethylsilyl 2-amino-l-carboxylates 213 were cyclized to the unstable 2-thioxoperhydro-l,3-oxazin-4-ones, which isomerize to the thermodynamically more stable perhydro-l,3-thiazine-2,4-diones 215 (cm, X = CH2 — CH2, CH = CH trans, X = CH2-CH2) (74MI2). 

Aromatization of alicyclic compounds. Cyclohexane carboxylic acids maybe metabolized by a mitochondrial enzyme system to an aromatic acid such as benzoic acid. This enzyme system requires CoA, ATP, and oxygen and is thought to involve three sequential dehydrogenation steps after the initial formation of the cyclohexanoyl CoA (Fig. 4.36). The aromatase enzyme also requires the cofactor FAD. 

First, peak heights are measured at five points in the NMR spectra (Figure 2). All NMR spectra of fulvic acids described in this study were determined as the sodium salt in D20 at pH 8 (21). Peak heights were used rather than peak areas to minimize overlapping spectral contributions from various proton structures. From structural-model considerations, peak 1 appears to be a combination of methylene and methine protons in aliphatic alicyclic rings and branched methyl groups located beta to carbonyl groups of a carboxylic acid, ester, or ketone. The structural model rules out meth-... 

Potassium permanganate oxidation of a vinyl group to a carboxyl group can be used to prepare fluorinated carboxylic acids with aliphatic (. < ] (equauon 30) or alicyclic [39] (equation 31) skeletons... 

The alicyclic carboxylic acid derivatives have been studied extensively and, to date, with the exception of the compounds already mentioned, relatively few have been found lo possess commercially important potential as pesticides. An exception is dimethyl carhate (Dimcllon), which finds use as a repellent for certain blood-sucking diptcra. The compound frequently is mixed with other pesticides. 

Carbonyl compounds will be taken in this chapter to mean any organic compound that contains at least one carbon-oxygen double bond where we limit the substitution to only saturated aliphatic, saturated alicyclic and aryl hydrocarbyl groups. Carbonyl compounds with a variety of unsaturated substituents have earlier been discussed within the context of enones4. Non-hydrocarbyl substituents, X , may be directly attached to the carbonyl and elsewhere in the molecule. The first type of species, RCOX, is alternatively identified as acyl derivatives such as carboxylic acids and their esters, halides and amides and have already been discussed in a recent Patai thermochemistry... 

The carboxyl group of aliphatic and alicyclic carboxylic acids may be protected by conversion into a variety of organic esters silylation affords a valuable alternative. 

Esterification with alicyclic alcohols proceeds best when the alcohol is saturated with hydrogen chloride and treated with an excess of the carboxylic acid (the Fischer-Speier method) a very impure ester results if sulphuric acid is used as the catalyst. 

The presence of acid substances in petroleum first appears to have been reported in 1874 and it was established nine years later that these substances contained carboxyl groups and were carboxylic acids. These were termed naphthenic acids. Although alicyclic (naphthenic) acids appear to be the more prevalent, it is now well known that aliphatic acids are also present. In addition to the carboxylic acids, alkaline extracts from petroleum contain phenols. 

Uses The alicyclic hydrocarbons have numerous industrial applications. Cyclopropane (C3H6) is used as an anesthetic. Cyclohexane (CgH ) is used as a chemical intermediate as an organic solvent for oils, fats, waxes, and resins and for the extraction of essential oils in perfume manufacturing industries. Cyclohexene (C6H10) is used in the manufacture of maleic acid, cyclohexane carboxylic acid, and adipic acid. Methyl cyclohexane (C7H14) is used for the production of organic synthetics such as cellulose ethers. These compounds are used in different industries such as adipic acid makers, benzene makers, fat processors, fungicide makers, lacquerers, nylon makers, oil processors, paint removers, plastic molders, resin makers, rubber makers, varnish removers, and wax makers. 

Alicyclic P-lactams 28 were successfully synthesized via a parallel liquid-phase Ugi four-center three-component reaction, starting from alicyclic P-amino acids such as cis-2-aminocyclohexanecarboxylic acid, c/.s-2-aminocyclopentanecarboxylic acid, 2,3-diexo-3-aminobicyclo-[2.2.1]heptane-2-carboxylic acid and some of their partially unsaturated analogues <02OL1967>. 

The proton affinities of alicyclic carboxylic acids are identical within 5 kj mol-1, with cyclohexane >cyclopropane >cyclopentane >cyclobutane [205]. This quite surprising situation seems not to be fully explained yet. 

---