IUPAC nomenclature system

A chemical name typically has four parts in the IUPAC system of nomenclature prefix, locant, parent, and suffix. The prefix specifies the location and identity of various substituent groups in the molecule, the locant gives the location of the primary functional group, the parent selects a main part of the molecule and tells how many carbon atoms are in that part, and the suffix identifies the primary functional group. 

The naming of these three heterocyclic fused (5 5 5) ring systems has been carried out according to the IUPAC system of nomenclature. Some examples are given as follows compound la (Table 1) is named (3-hydroxy-4-methoxyphenylthieno[2,3-3]pyrrolizin-8-one. Compound 15a (Table 2) is dithieno[3,2-3 2, 3 - 1thiophene. Compound 23a (Table 2) is dithieno[3,2-3 2, 3 - 1pyrrole. Compound 20a (Table 2) is dithicno[3,2-3 2, 3 -r/]thiophene-4,4-dio ide. Compound 13b (Table 2) is 3,4-dimethyldithieno[3,2-3 2, 3 -i/]thiophene-7,7-dioxide. Compound 38 (Table 4) is fM, r, r-10-azatricyclo[5.2.1.01 10]deca-2,5,8-triene. Compound 39 (Table 4) is cis,cis, m-10-azatricyclo[5.2.1.01 10]deca-2,8-diene. The nomenclature of compound 40 (Table 4) is 1,4,7 triaza tricy-clo[5.2.1.01,10]decane. 

In the/flc isomer, the three chloride ions are located on the corners of one of the triangular faces of the octahedron. In the mer isomer, the three chloride ions are located around an edge (meridian) of the octahedron. The IUPAC system of nomenclature does not use this approach. A summary of the IUPAC procedures is presented in the book by Huheey, Keiter, and Keiter that is cited in the references listed at the end of this chapter. 

Fig. 2. Nomenclature of the heme group of horseradish peroxidase according to the lUB/IUPAC system. Proton-bearing carbon atoms are numbered on the structure and can be cross-referenced with the Fischer system as follows ...

In the IUPAC system locants are placed immediately before the part of the name to which they apply for instance subunits such as pyridine-2,4-diyl and l-methylpropane-l,3-diyl. One of the few exceptions is the phenylene subunit, for example, 1,4-phenylene in XV. The IUPAC nomenclature system is always evolving and some of the details (e.g., the names of some subunits) have changed in recent years. One should use caution when using less recent nomenclature references than those listed in this text. 

The IUPAC nomenclature system recognizes that most of the common (commercial) polymers have source-based or semisystematic names that are well established by usage. IPUAC does not intend that such names be supplanted by the IUPAC names but anticipates that such names will be kept to a minimum. The IUPAC system is generally used for all except the common polymers. The IUPAC names for various of the common polymers are indicated below the more established source or semisystematic name in the following ... 

It is unfortunate that two systems of nomenclature are currently being used in this area. Though this author, like most in the United States, has a personal preference for the Fischer system (11) (because it retains a link with the monumental body of earlier work), the IUPAC system (12) is mandated in this chapter. To be sure, the IUPAC system has its advantages, not the least of which is the correlation of atoms between the porphyrin (12) and corrin (13) chromophore. 

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). 

Although epoxides are always considered to have their oxygen atom as part of a three-membered ring, the prefix epoxy in the IUPAC system of nomenclature can be used to denote a cyclic ether of various sizes. Thus... 

Systematic nomenclature (Section 2.11) Names for chemical compounds that are developed on the basis of a prescribed set of rules. Usually the IUPAC system is meant when the term systematic nomenclature is used. 

Since the new IUPAC recommendations [5], the nomenclature of quinic acid isomers is very confusing in the literature. Therefore, the latest IUPAC nomenclature is used throughout this paper instead of the older, but still useful, nomenclature. In the IUPAC nomenclature quinic acid is now treated as cyclitol. In the preferred configuration, the carboxy group and the C-4 and C-5 hydroxy groups are equatorial, with the C-l and C-3 hydroxy groups are axial. In the IUPAC system, the former 3-O-acylquinic acids are now renamed 5-O-compounds, and the... 

The saccharides have long and awkward names by the IUPAC system, consequently a highly specialized nomenclature system has been developed for carbohydrates. Because this system (and those like it for other natural products) is unlikely to be replaced by more systematic names, you will find it necessary to memorize some names and structures. It will help you to remember the meaning of names such as aldopentose and ketohexose, and to learn the names and details of the structures of glucose, fructose, and ribose. For the rest of the carbohydrates, the nonspecialist needs only to remember the kind of compounds that they are. 

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. 

Unlike the lack of logic in the IUPAC system that results when additional "fused polycyclic hydrocarbons" are named by addending rings to one of these "privileged" 35 reference compounds at specified locations, it is highly desirable that the nomenclature for all ring systems uses the same criteria. This is another virtue of proposed system. Meanwhile a close scrutiny of the molecules depicted in Tables 1 and 2 reveal ... 

In addition to differences described in Chapters 1 and 2 between the proposed system of nomenclature versus the present, internationally-accepted standard IUPAC system, such as ... 

We have been using the common nomenclature of ethers, which is sometimes called the alkyl alkyl ether system. The IUPAC system, generally used with more complicated ethers, is sometimes called the alkoxy alkane system. Common names are almost always used for simple ethers. 

Refs. [i] Inczedy I Lengyel T, Ure AM (1998) Compendium of analytical nomenclature (IUPAC definitive rules, The Orange Book ), 3rd edn. Blackwell Science, Oxford [ii] Newman, Thomas-AlyeaKE (2004) Electrochemical Systems, 3rd edn. Wiley Interscience, Hoboken, pp 280... 

The system of nomenclature used in this book is the IUPAC system. 

The common method of naming aldehydes corresponds very closely to that of the related acids (see Carboxylic acids), in that the term aldehyde is added to the base name of the acid. For example, formaldehyde (qv) comes from formic acid, acetaldehyde (qv) from acetic acid, and butyraldehyde (qv) from butyric acid. If the compound contains more than two aldehyde groups, or is cyclic, the name is formed using carbaldehyde to indicate the functionality. The IUPAC system of aldehyde nomenclature drops the final e from the name of the parent acyclic hydrocarbon and adds al. If two aldehyde functional groups are present, the suffix - dial is used The prefix formyl is used with polyfunctional compounds. Examples of nomenclature types are shown in Table 1. 

The compounds discussed in this review are represented by the general structure 1. In the IUPAC system of nomenclature 5), a specific member of this group (as represented by structure 2) is named... 

Many organic compounds have informal common names but the accepted way of naming compounds is by the IUPAC system of nomenclature. 

Note to the student The IUPAC system of nomenclature has a well defined set of rules determining how structures are named. You will find a summary of these rules as Appendix 1 in this Solutions Manual. 

Note to the student The IUPAC system of nomenclature is undergoing many changes, most notably in the placement of position numbers. The new system places the position number close to the functional group designation, which is what this Solutions Manual will attempt to follow however, you should be able to use and recognize names in either the old or the new style. Ask your instructor which system to use. 

The purpose of the IUPAC system of nomenclature is to establish an international standard of naming compounds to facilitate communication. The goal of the system is to give each structure a unique and unambiguous name, and to correlate each name with a unique and unambiguous structure. 

As the science of organic chemistry slowly grew in the 19th century, so too did the number of known compounds and the need for a systematic method of naming them. The system of nomenclature we ll use in this book is that devised by the International Union of Pure and Applied Chemistry (IUPAC, usually spoken as eye-you-pac). 

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