Carboxyl group conjugation

Fatty acids containing acetylenic bonds, double bonds close to the carboxyl group, conjugated unsaturation, or other reducible (e.g., keto) groups rarely add the... 

The chemical reactivity of sorbic acid is determined by the conjugated double bonds and the carboxyl group. 

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. 

Alkali fusion of oleic acid at about 350°C ia the Varrentrapp reaction causes double-bond isomerization to a conjugated system with the carboxylate group followed by oxidative cleavage to form palmitic acid (75). In contrast, alkaU fusion of riciaoleic acid is the commercial route to sebacic acid [111 -20-6] ... 

These two selectors terminated with a glycine were then prepared on a larger scale, their carboxyl groups reacted with 3-aminopropyltriethoxysilane, and the conjugate immobilized onto silica. Each CSP was packed into columns and used for the separation of racemic (l-naphthyl)leucine ester 17. Separation factors of 6.9 and 8.0 were determined for the columns with DNB-ala-gly and DNB-leu-gly selector respectively. These were somewhat lower than those found for similar CSPs using the parallel synthesis and attached through a different tether [87]. 

COOH simple monocarboxylic acids do not react, but dicarboxylic acids in which the carboxyl groups are conjugated with each other do ... 

Decarboxylation of copolymers of propynoic acid and phenylacetylene of varying composition was found to manifest an increase in reactivity of the carboxylic groups with increasing concentration of conjugated double bonds in the chain. 

The carboxylate functionalized primary bisphosphines P2S2COOH 18 and P2N2COOH 19 (Schemes 7 and 8) provide new opportunities for use in catalytic and biomedical motifs. The carboxylate groups in 18 and 19 can be used to conjugate these phosphine hgating units on to peptides or proteins. 

During P-elimination of pectic substances, a double bond is created between C-4 and C-5 of the new non-reducing end, leading to absorbance at 235 nm (by conjugation with the carboxyl groups). This spectral property of p-eliminated pectins was used to follow their... 

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