Nomenclature systems common system

The nomenclature system commonly in use is known as the IUPAC Rules. These rules are as follows ... 

Names of Ionic Compounds Flydrates Summary of the Nomenclature System Common Names of Chemicals... 

Heteroeyeles structurally based on the phenalene ring system form an interesting elass, frequently possessing distinetive eolours. With nitrogen as the central atom we have the unstable 9b-azaphenalene (24), whieh has only fairly reeently been prepared and is still comparatively little studied (76JCS(Pl)34l). The cyclazine nomenclature is commonly applied to this and related compounds thus, (24) is (3.3.3)cyclazine. With further aza substitution, in positions alternant to the central atom, their stability increases the heptaazaphenalene (25) is (thermally) a very inert compound, derivatives of which, e.g. the triamine, have been known since the early days of organic chemistry (see Chapter 2.20). 

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 ... 

We will base our study on the system developed by the International Union of Pure and Applied Chemistry. The system is called the IUPAC Rules. There are other semi-systematic nomenclature systems, and many individual compounds are known by nonsystematic or trivial names. These names will be given along with the IUPAC names when such trivial names are commonly used. 

In this section the various nomenclature systems in common use will be described first, then their application and some particular problems... 

Ideally, every organic substance should have a completely descriptive, systematic name to permit only one structural formula to be written for it. This ideal has been approached closely in some of the current nomenclature systems but, unfortunately, truly systematic nomenclature for very complicated compounds is often hopeless for conversational or routine scripto-rial purposes. As a result, we will at times resort to using (common) trivial names, especially if it is impractical to do otherwise. Clearly, the description 9-(2,6,6-trimethyl-l-cyclohexenyl)-3,7-dimethyl-2,4,6,8-nonatetraen-J-ol has phonetic disadvantages as a handy name for vitamin A ... 

The description of ci-amino acids as D or L is a holdover from an older nomenclature system. In this system (5)-alanine is called L-alanine. The enantiomer would be D- or ( )-serine. The l (laevo, turned to the left D = dextro, turned to the right) designation refers to the ct-carbon in the essential amino acids. In alanine, there is a single a-carbon that is asymmetric. When two asymmetric centers are present as in L-threonine, the stereochemistry of both carbons must be considered. The common form of L-threonine is the 25,3R stereoisomer. 

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. 

The nomenclature system outlined in this report follows many customary terpene practices but also conforms to established nomenclature rules and practices. The resulting terpene-like names are much simpler than the strict systematic names formed according to IUPAC rules. Replacement of the currently used common terpene names by the recommended ter-pene-like pseudosystematic names will facilitate ready recognition of the terpene hydrocarbon structures and will aid in integrating terpene chemistry with the entire field of organic chemistry. Extension of the hydrocarbon rules to the naming of functional derivatives will simplify and unify nomenclature within the terpene field. 

As was noted in CHEC-II(1996), a variety of names have been used for derivatives of pyrans and their benzo derivatives and many of these naming conventions have been reviewed in earlier works <1977HC(31), 1981HC(36)>. In the interests of continuity, and also because the use of common or trivial names is widespread in the literature, this chapter will also employ the nomenclature system that was employed in the corresponding chapter in GHEC-II(1996) <1996CHECII(5)301>. This material is reproduced for the readers benefit below. 

With a few exceptions for common chemical names, nomenclature in the tables follows the Chemical Abstracts nomenclature system. 

Unlike the disjoint sets of approaches to taxonomy and nomenclature for "organic chemistry" vs. "inorganic chemistry" vs. "polymer chemistry", etc., which form the cornerstone of all of the various nomenclature systems in common usage today, a common graph theory based, bi-parametric, alternating code of atoms and bonds that is equally applicable to each of these individual domains is proposed. In this system the detailed formula will be all of the name that is needed. Advantages to such an approach include ... 

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. 

For reference to amino acid residues of prolylisomerase substrates and their corresponding enzyme subsites, we will adopt the nomenclature system of Schecter and Berger (1967) that is commonly used in protease chemistry. According to this system, if isomerization occurs at the Pi-P bond, and P, is Pro, the amino acid residues of the peptide substrate are named P - -P3-P2-Pi-P -P2 -P3 P , while the corresponding enzyme subsites are named S - S3-S2-Si-Sj -S2 -S3 - -Sn. 

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