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Carboxyl compounds definition

Oakmoss. Extracts of oakmoss are extensively used in perfumery to furnisli parts of the notes of the fougnre or chypre type. The first step in the preparation of an oakmoss extract is treatment of the Hchen Evemiaprunastri (L.) Ach., collected from oak trees mainly in southern and central Europe, with a hydrocarbon solvent to obtain a concrete. The concrete is then further processed by solvent extraction or distillation to more usable products, of which absolutes are the most versatile for perfumery use. A definitive analysis of oakmoss volatiles was performed in 1975 (52). The principal constituents of a Yugoslav oakmoss are shown in Table 15 (53). A number of phenoHc compounds are responsible for the total odor impression. Of these, methyl P-orcinol carboxylate is the most characteristic of oakmoss. [Pg.314]

Instead of the definition in Eq. (7-82), the selectivity is often written as log k,). Another way to consider a selectivity-reactivity relationship is to compare the relative effects of a series of substituents on a pair of reactions. This is what is done when Hammett plots are made for a pair of reactions and their p values are compared. The slope of an LEER is a function of the sensitivity of the process being correlated to structural or solvent changes. Thus, in a family of closely related LFERs, the one with the steepest slope is the most selective, and the one with the smallest slope is the least selective.Moreover, the intercept (or some arbitrarily selected abscissa value, usually log fco for fhe reference substituent) should be a measure of reactivity in each reaction series. Thus, a correlation should exist between the slopes (selectivity) and intercepts (reactivity) of a family of related LFERs. It has been suggested that the slopes and intercepts should be linearly related, but the conditions required for linearity are seldom met, and it is instead common to find only a rough correlation, indicative of normal selectivity-reactivity behavior. The Br nsted slopes, p, for the halogenation of a series of carbonyl compounds catalyzed by carboxylate ions show a smooth but nonlinear correlation with log... [Pg.372]

The study of optical isomers has shown a similar development. First it was shown that the reduction potentials of several meso and racemic isomers were different (Elving et al., 1965 Feokstistov, 1968 Zavada et al., 1963) and later, studies have been made of the ratio of dljmeso compound isolated from electrolyses which form products capable of showing optical activity. Thus the conformation of the products from the pinacolization of ketones, the reduction of double bonds, the reduction of onium ions and the oxidation of carboxylic acids have been reported by several workers (reviewed by Feokstistov, 1968). Unfortunately, in many of these studies the electrolysis conditions were not controlled and it is therefore too early to draw definite conclusions about the stereochemistry of electrode processes and the possibilities for asymmetric syntheses. [Pg.171]

A further successful attempt to detect a,(3-unsaturated SPC (SPC-2H) during the degradation of LAS was achieved by Eichhorn and Knepper [34] (Fig. 5.1.8). An SPC-2H has m/z of two mass units below that of the corresponding SPC, and compounds of this type have been described in the degradation of impurities in LAS, the monocarboxylated DATS [88,104]. However, a definite distinction between the known DATS carboxylates [88] and the putative SPC-2H could be provided by LC-ESI-MS analysis, which enabled structural assignment via... [Pg.573]

The name, maleic anhydride, came about in the same fashion. as any number of compounds early in the petrochemical Business Many organic acids and their derivatives were given common names based on some early observations, their special source in nature, or on some special feature of their structure. MA was first isolated in the 1850—75 era by dehydration of malic acid, a sugar acid found in apple juice. The Latin word for apple is malum. Hence, malum, malic, maleic. The suffix, anhydride, which follows each alias of MA, has a simple definition a compound derived by the loss of a molecule of water from two carboxyl groups (-COOH). [Pg.293]

NOM is common in sediments, soils, and near ambient (<50 °C) water. The materials result from the partial decomposition of organisms. They contain a wide variety of organic compounds, including carboxylic acids, carbohydrates, phenols, amino acids, and humic substances (Drever, 1997, 107-119 Wang and Mulligan, 2006, 202). Humic substances are especially important in interacting with arsenic. They result from the partial microbial decomposition of aquatic and terrestrial plants. The major components of humic substances are humin, humic acids, and fulvic acids. By definition, humin is insoluble in water. While fulvic acids are water-soluble under all pH conditions, humic acids are only soluble in water at pH >2 (Drever, 1997, 113-114). [Pg.106]

On the basis of this simple definition he searched for bioisosteres of propionic acid. Using the COSMOfrag database of 28,000 compounds he found several interesting compounds within the top 20 most similar compounds of propionic acid (see Fig. 11.17). While six small carboxylic acids are ranked as most similar to propionic acid, eight non-acidic compounds with quite different chemical skeletons follow, between ranks 7 and 19. Some of them are well known as suitable bioisosters of propionic acid, while the others may be tested as such. [Pg.200]

Ranbaxy alleged that because the compound of claim 2 was specifically described only as the carboxylic acid, it did not allow for the possibility of a hemicalcium salt meaning that the compound of claim 6 could not be the salt either claim 6 depends on claim 2 and, therefore, cannot expand the definition of claim 2.52 The CAFC agreed... [Pg.53]

In conclusion, even though there is the definite correlation between carboxylic group index and minimum in respect to graftability in our system, a detailed work with model compounds would be required to futher elucidate the mechanism of lignin participation in the copolymerization reaction. [Pg.281]

An acid is a compound capable of donating a proton to another compound (this is the so-called Br0nsted definition). The substance CH3COOH is an acid, acetic acid. However, because the dissociation of all the carboxyl groups is not complete when acetic acid is dissolved in water, acetic acid is referred to as a weak acid. The dissociation reaction for any weak acid of type HA in water is... [Pg.58]


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See also in sourсe #XX -- [ Pg.221 ]




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