Compounds, continued naming

In this case the longest continuous chain has five carbon atoms the compound is named as a derivative of pentane The key word here is continuous It does not matter whether the carbon skeleton is drawn m an extended straight chain form or m one with many bends and turns All that matters is the number of carbons linked together m an uninterrupted sequence... 

As numbered on the structural formula the longest continuous chain contains eight car bons and so the compound is named as a derivative of octane Numbering begins at the end nearest the branch and so the ethyl substituent is located at C 4 and the name of the alkane is 4 ethyloctane... 

In the IUPAC system, the four methine positions are conveniently numbered 5, 10, 15 and 20, and the eight remaining peripheral positions fall at 2, 3, 7, 8, 12, 13, 17 and 18. The nitrogen atoms are numbered 21 through 24. Owing to the continued use of trivial names, both in the IUPAC and classical systems of nomenclature, certain other features of porphyrin notation and isomerism need to be explained. If the eight peripheral substituents are made up of two sets of four (for example, four methyls and four ethyls), and if there is one of each on the individual pyrrole subunits (a situation which usually occurs in biologically derived porphyrins), then there are four possible so-called primary type isomers. These four isomers for the methyl/ethyl series, trivially named etioporphyrins, are shown in Scheme 1 the compounds are named etioporphyrin-I (14), etioporphyrin-II (15), etioporphyrin-III (16), and etioporphyrin-IV (17). 

In compound A, the longest continuous chain is live carbon atoms long, and there are no multiple bonds, so this compound is named as a pentane (see Table 20.1). The carbon atom to which the methyl group (CH3—) is attached is identified with the number 2 because that carbon is the second from the nearer end of the chain. The name is 2-methylpentane. Note that the number 2 is an address and does not mean two methyl groups. 

If the methyl group is attached to the first carbon atom, the longest continuous chain of carbon atoms includes the methyl group. The compound s name is heptane. 

Other compounds were named by their discoverer for more personal reasons. Adolf von Baeyer supposedly named barbituric acid after a woman named Barbara, although speculation continues on Barbara s identity—a lover, a Munich waitress, or even St. Barbara. 

Four carbons are in the longest continuous chain, so butane is the parent chain and wiU be part of the compound s name. There is only one branch, and it contains one carbon. Instead of calling this a methane branch, change the -ane in methane to -//. Thus, this is a methyl branch. Because the methyl branch is attached to the second carbon of the butane chain, this compound has the name 2-methylbutane. 

Propane will be part of this compound s name because the longest continuous chain has three carbons. Two methyl branches are present, both on the second carbon. To indicate the presence of more than one branch of the same kind, use the same Greek prefixes presented in Chapter 5 for naming hydrates and molecules. The prefix to use when two of anything are present is di-. Thus, the name of this compound is 2,2-dimethyl-propane. Note that the positions where the methyl groups are attached to the parent chain are written, separated by a comma. 

The longest continuous chain has six carbons, but the longest continuous chain containing the OH functional group has five carbons so the compound is named as a pentanol. 

If the same number for the aUcene functional group suffix is obtained in both directions, the correct name is the name that contains the lowest substituent number. For example, 2,5-dimethyM-octene is a 4-octene whether the longest continuous chain is numbered from left to right or from right to left. If you number from left to right, the substituents are at positions 4 and 7, but if you number from right to left, they are at positions 2 and 5. Of those four substituent numbers, 2 is the lowest, so the compound is named 2,5-dimethyM-octene and not... 

Names, Structural Formulas, Dosage, and Dosage Forms of Selected Cephalosporins and Related Compounds (Continued)... 

Steam distillation continuous extraction of the raisins under reduced pressure gave a volatile raisin oil which amounted to 5-10 ppm of the raisins. The oil was analyzed by capillary GLC-mass spectrometry (GLC-MS). The analysis was repeated with volatile oils from several different samples of raisins. Figure I shows a GLC analysis of typical oil. The results are listed In Table I. Peak numbers corresponding to the peaks In Figure I are shown In the first column of Table I alongside the compound s name. Some Idea of the approximate relative percentages of the components In a typical oil (calculated from peak areas) Is also listed In Table I. 

Select the longest continuous chain of carbon atoms as the parent compound, and consider all alkyl groups attached to it as branch chains or substituents that have replaced hydrogen atoms of the parent hydrocarbon. If two chains of equal length are found, use the chain that has the larger number of substituents attached to it as the parent compound. The alkane s name consists of the parent compound s name prefixed by the names of the alkyl groups attached to it. 

In the presence of alcohols, the reactive species is a carbenium ion (4), formed from the hemiacetal (5) (Eq. 7). Efforts to synthesize model compounds continue the work started by Bender and coworkers. A series of new dimeric and trimeric compounds, derived from o-cresol, have been synthesized and their structures determined by IR, NMR, and elemental analysis. Additional homologues of p-cresol have been prepared by Kammerer and Niemann, to study the melting behavior of a wide range of methylene-bridged phenol oligomers. Prepolymer formation, namely novolac production, has been studied in batch and continuous flow reac-... 

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