Hydroxyl-containing compounds phenols

In this respect, particular interest is attached to those studies which show a correlation between the O—H vibration frequencies measured in hydrogen-bonded associates of various hydroxyl-containing compounds (phenols, alcohols) with various donor molecules and the AH values for formation of the associates. 

It is well known 113,14 20 25> that the addition of hydroxyl-containing compounds (water, alcohols, phenols, acids) considerably promotes the interaction of epoxy compounds with amines and other nucleophilic reagents. In this case, the epoxy ring carbon atom becomes more sensitive to nucleophilic attack. The reaction proceeds through a trimolecular transition state initially suggested by Smith26 27) for the reactions of epoxy compounds with amines2... 

Thus, for instance, the formation of trimethylsilyl esters, alcohols and phenols or other hydroxyl-containing compounds not only improves chromatographic separations, but also is a method for the analysis of hydroxyl groups. The reagents used in this instance are, however, not very selective as they react with several classes of compounds. For instance, N,0-bis(trimethyl)acetamide also reacts with organic acids, amines, aromatic amides, urea derivatives and some enols [19, 20]. Therefore, this technique should desirably be used in combination with other methods or for converting involatile... 

Probably the most common preparative method involves the reaction of a sulphonyl chloride with a hydroxyl-containing compound, in the presence of a base. An extremely weak base, like sodium carbonate, may also be used in some instances353. The first reported example of this type of reaction being as early as I860354. This reaction occurs with both alcohols and phenols, in the presence of a base306-308,355-372, as shown in equation 81. 

Germanes undergo oxidative condensation in the presence of Cu-powder with certain hydroxyl-containing compounds such as water, alcohols, phenols, carboxylic acids, and boric acid.— E ... 

We 11 Start by discussing m more detail a class of compounds already familiar to us alcohols Alcohols were introduced m Chapter 4 and have appeared regularly since then With this chapter we extend our knowledge of alcohols particularly with respect to their relationship to carbonyl containing compounds In the course of studying alco hols we shall also look at some relatives Diols are alcohols m which two hydroxyl groups (—OH) are present thiols are compounds that contain an —SH group Phenols, compounds of the type ArOH share many properties m common with alcohols but are sufficiently different from them to warrant separate discussion m Chapter 24... 

The olives themselves contain many phenolic compounds with antioxidant properties. Bouaziz et al. (2005) investigated the olive cultivar Chemlali from Tunisia. Oleuropein (7.14), a bitter glycoside esterified with a phenolic acid, was the major compound present. Phenolic monomers and twelve flavonoids were also identified. The antioxidant activity of the extract was evaluated. Acid hydrolysis of the extract enhanced its antioxidant activity. / -Hydroxyphenyl-cthanol (7.12) and quercetin (1.43) showed antioxidant activities similar to that of 2,6-di-fert-butyl-4-methyl phenol (7.15), a reference compound with known antioxidant properties. It was suggested that a hydroxyl group at the ortho-position on the flavonoid B ring could contribute to the antioxidant activity of the flavonoids. 

The dansylation of estrogens which contain a phenolic hydroxyl group has been used for the sensitive analysis of these compounds in urine [105—107]. The derivatives are separated by TLC and are examined visually under UV light (excitation, 346 nm emission, 525 nm). The derivatives are quantitated by removing the spots followed by fluorescence measurements in solution, or by direct evaluation of the chromatoplates in situ. 

When aromatic compounds containing a phenolic OH group are brought in contact with titanosilicates in the presence of H2O2, two reactions are possible the first is the hydroxylation of the aromatic ring to give diphenols (Section... 

Synthetic antioxidants are manmade and are used to stabilize fats, oils, and lipid-containing foods and are mostly phenolic-based. Many compounds are active as antioxidants, but only a few are incorporated into food because of strict safety regulations. These phenolic derivatives usually contain more than one hydroxyl or methoxy group. Ethoxyquin is the only heterocyclic, N-containing compound that is allowed for use in animal feeds. 

There is probably formed, from the carbonic and hydrochloric acids, an intermediate add-chloride whidx, as jnst described, reacts with the alcohol. The add-chlorides are also used to determine whether a substance under examination contains an alcoholic or a phenol hydroxyl group or not. If the compound reacts readily with an acid-eliloride, it contains either alcoholic or phenol hydroxyl, since compounds containing oxygen in some other form of combination, e.g., as in ethers, do not react with acid-chlorides. 

Phenolic. Of, relating to, or containing a phenol group which is a hydroxyl group bonded directly to an aromatic ring structure for example, naphthol is a phenolic compound oh... 

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