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Nomenclature phenols

Generally the name of a compound should correspond to the most stable tautomer (76AHCS1, p. 5). This is often problematic when several tautomers have similar stabilities, but is a simple and reasonable rule whose violation could lead to naming phenol as cyclohexadienone. Different types of tautomerism use different types of nomenclature. For instance, in the case of annular tautomers both are named, e.g., 4(5)-methylimidazole, while for functional tautomerism, usually the name of an individual tautomer is used because to name all would be cumbersome. In the case of crystal structures, the name should reflect the tautomer actually found therefore, 3-nitropyrazole should be named as such (97JPOC637) and not as 3(5)-nitropyrazole. [Pg.6]

The distinction between aryldialkylphosphatase, also called paraoxonase (Sect. 2.5.6 and 3.7), and arylesterase was introduced in the last printed revision of the nomenclature recommendations [1], Arylesterases (EC 3.1.1.2) act on many phenolic esters [66] [67] aryldialkylphosphatases (aryltriphos-... [Pg.45]

In far too many instances trade-name polymer nomenclature conveys very little meaning regarding the structure of a polymer. Many condensation polymers, in fact, seem not to have names. Thus the polymer obtained by the step polymerization of formaldehyde and phenol is variously referred to a phenol-formaldehyde polymer, phenol-formaldehyde resin, phenolic, phenolic resin, and phenoplast. Polymers of formaldehyde or other aldehydes with urea or melamine are generally referred to as amino resins or aminoplasts without any more specific names. It is often extremely difficult to determine which aldehyde and which amino monomers have been used to synthesize a particular polymer being referred to as an amino resin. More specific nomenclature, if it can be called that, is afforded by indicating the two reactants as in names such as urea-formaldehyde resin or melamine-formaldehyde resin. [Pg.16]

Production of phenol and acetone is based on liquid-phase oxidation of isopropylbenzene. Synthetic fatty acids and fatty alcohols for producing surfactants, terephthalic, adipic, and acetic acids used in producing synthetic and artificial fibers, a variety of solvents for the petroleum and coatings industries—these and other important products are obtained by liquid-phase oxidation of organic compounds. Oxidation processes comprise many parallel and sequential macroscopic and unit (or very simple) stages. The active centers in oxidative chain reactions are various free radicals, differing in structure and in reactivity, so that the nomenclature of these labile particles is constantly changing as oxidation processes are clarified by the appearance in the reaction zone of products which are also involved in the complex mechanism of these chemical conversions. [Pg.14]

The synthesis of a typical p-blocker starts with the mono-alkylation of catechol to give the ether (19-1). Application of the standard side chain budding sequence leads to the nonselective (3-blocker oxprenolol (19-2) [16] (the olol ending is approved USAN nomenclature for (3-blockers). Atenolol (19-5) is one of the most widely used (3i selective agents. The requisite phenol (19-4) can be obtained by ester interchange of methyl 4-hydroxyphenylacetate (19-3) with ammonia. Elaboration of the thus obtained intermediate (19-4) via the customary scheme then affords atenolol (19-5) [17]. [Pg.55]

Using Dr. Bergers nomenclature it seems that where x = 2, which is the case for most phenolic antioxidants, the number of ROOH ultimately produced for every molecule of antioxidant consumed, will also equal 2 therefore, the middle term in his second equation would be... [Pg.182]

Simple phenolics are substituted phenols. The ortho, meta and para nomenclature refers to a 1,2-, 1,3- and 1,4-substitution pattern of the benzene ring, respectively, where in this case one of the functional groups is the hydroxyl group. With three functional groups, the substitution pattern can be 1,3,5, which, when all three substituents are identical, is designated as a mt /fl-tri-substitution pattern, whereas the 1,2,6, substitution pattern is indicated by the prefix v/c (Figure 1-1). [Pg.3]

Figure 1-1. Nomenclature for substitution patterns of phenolic compounds. R, R and R2 are generic substituents. Figure 1-1. Nomenclature for substitution patterns of phenolic compounds. R, R and R2 are generic substituents.
An alternative mechanism for the oxidation of phenolic compounds is enzyme-catalyzed oxidation. Several classes of enzymes can catalyze this reaction. According to the Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB), these enzymes are part of the E C. 1 class of oxidoreductases (see the Internet web site http //www.chem.qmul.ac.uk/iubmb/enzyme/ECl). The three main classes of enzymes that catalyze the oxidation of phenolic compounds are the oxidoreductases that use oxygen as electron acceptor (E.C. 1.10.3), the peroxidases (E.C. 1.11.1), and monophenol monooxygenase (E.C. [Pg.50]

The focus of this book is centered on structure, nomenclature and occurrence of phenolic compounds (Chapter 1), and their chemical properties (Chapter 2). Chapter 3 describes the biosynthetic pathways leading to the major classes of phenolics. This chapter presents an up-to-date overview of the genetic approaches that have been used to elucidate these pathways. Chapter 4 presents an overview of methods for the isolation and identification of plant phenolic compounds. Given that much of the recent... [Pg.285]

When a phenol molecule is substituted with additional groups, either the ortho, meta, para system or the numbering system can be employed. In either case, if the parent molecule is referred to as a phenol, the nomenclature being used is the common system. [Pg.55]

The nomenclature of benzene derivatives is described in Sec. 4.6. Common names and structures to be memorized include those of toluene, styrene, phenol, aniline, and xylene. Monosubstituted benzenes are named as benzene derivatives (bromobenzene, nitrobenzene, and so on). Disubstituted benzenes are named as ortho- (1,2-), meta- (1,3-), or para- (1,4-), depending on the relative positions of the substituents on the ring. Two important groups are phenyl (C6H5-) and benzyl (C6H5CH2-). [Pg.61]

In the IUPAC system of nomenclature, the suffix for alcohols is -ol. Alcohols are classified as primary, secondary, or tertiary depending on whether one, two, or three organic groups are attached to the hydroxyl-bearing carbon. The nomenclature of alcohols and phenols is summarized in Secs. 7.1-7.3. [Pg.123]

Calix[ ]arenes are a family of macrocycles prepared by condensation reactions between n /v/ra-substituted phenols and n formaldehyde molecules under either base or acid catalysis. Different sizes of the macrocycles can be obtained (n = 4-20) (Stewart and Gutsche, 1999) depending on the exact experimental conditions, which were mastered in the 1960 s (Gutsche, 1998), but the most common receptors are those with n =4,6,8 (macrocycles with an odd number of phenol units are more difficult to synthesize). We use here the simplified nomenclature in which the number of phenolic units is indicated between square brackets and para substituents are listed first.4 Calixarenes, which can be easily derivatized both on the para positions of the phenolic units and on the hydroxyl groups, have been primarily developed for catalytic processes and as biomimics, but it was soon realized that they can also easily encapsulate metal ions and the first complexes with d-transition metal ions were isolated in the mid-1980 s (Olmstead et al., 1985). Jack Harrowfield characterized the first lanthanide complex with a calixarene in 1987, a bimetallic europium complex with p-terf-butylcalix[8]arene (Furphy etal., 1987). [Pg.280]

The classical Claisen rearrangement is the first and slow step of the isomerization of allyl aryl ethers to orf/to-allylated phenols (Figure 11.41). A cyclohexadienone A is formed in the actual rearrangement step, which is a [3,3]-sigmatropic rearrangement (see Section 11.1 for the nomenclature of sigmatropic rearrangements). Three valence electron pairs are shifted simultaneously in this step. Cyclohexadienone A, a nonaromatic compound, cannot be isolated and tautomerizes immediately to the aromatic and consequently more stable phenol B. [Pg.467]

Structure and Classification of Alcohols 425 10-3 Nomenclature of Alcohols and Phenols 427 10-4 Physical Properties of Alcohols 430 10-5 Commercially Important Alcohols 433 10-6 Acidity of Alcohols and Phenols 435 10-7 Synthesis of Alcohols Introduction and Review 438 Summary Previous Alcohol Syntheses 438 10-8 Organometallic Reagents for Alcohol Synthesis 440 10-9 Addition of Organometallic Reagents to Carbonyl Compounds 443... [Pg.11]

The term calix[n]arenes indicates a class of phenolic metacyclophanes derived from the condensation of phenols and aldehydes. The name was coined by Gutsche and derives from the Latin calix because of the vase-like structure that these macrocycles assume when all the aromatic rings are oriented in the same direction.1 The bracketed number indicates the number of aromatic rings and hence defines the size of the macrocycle. To identify the phenol from which the calixarene is derived, the para substituent is designated by name. Thus the cyclic tetramer derived from p-f-butylphenol and formaldehyde is named p-f-butylcalix[4]arene, or with a more systematic but still simplified nomenclature proposed by Gutsche and used in this chapter 5,11,17,23-Te trakis( 1,1 -dimethylethyl)-25,26,27,28-tetrahydroxy calix [4] arene, 1 (Scheme 7.1). The systematic name reported by Chemical Abstracts is pentacyclo[19.3.1.13,7.19 13.115 19]octacosa-l (25),3,5,7(28),9,11,13(27),15,17, 19(26), 21,23-dodecaene-25,26,27,28-tetrol-5,l l,17,23-tetrakis(l, 1 -dimethylethyl). [Pg.145]


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See also in sourсe #XX -- [ Pg.432 , Pg.993 ]

See also in sourсe #XX -- [ Pg.432 , Pg.993 ]

See also in sourсe #XX -- [ Pg.432 , Pg.993 ]

See also in sourсe #XX -- [ Pg.427 , Pg.428 , Pg.429 ]

See also in sourсe #XX -- [ Pg.407 , Pg.939 ]

See also in sourсe #XX -- [ Pg.436 , Pg.989 ]

See also in sourсe #XX -- [ Pg.412 , Pg.914 ]




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