Nomenclature systematic names

For simple compounds the main reference uses the systematic I.U.P.A.C. nomenclature, but other nomenclature is cross-referenced to the systematic name. 

Enzymes are classified in terms of the reactions which they catalyse and were formerly named by adding the suffix ase to the substrate or to the process of the reaction. In order to clarify the confusing nomenclature a system has been developed by the International Union of Biochemistry and the International Union of Pure and Applied Chemistry (see Enzyme Nomenclature , Elsevier, 1973). The enzymes are classified into divisions based on the type of reaction catalysed and the particular substrate. The suffix ase is retained and recommended trivial names and systematic names for classification are usually given when quoting a particular enzyme. Any one particular enzyme has a specific code number based upon the new classification. 

The systematic lUPAC nomenclature of compounds tries to characterize compounds by a unique name. The names are quite often not as compact as the trivial names, which are short and simple to memorize. In fact, the lUPAC name can be quite long and cumbersome. This is one reason why trivial names are still heavily used today. The basic aim of the lUPAC nomenclature is to describe particular parts of the structure (fi agments) in a systematic manner, with special expressions from a vocabulary of terms. Therefore, the systematic nomenclature can be, and is, used in database systems such as the Chemical Abstracts Service (see Section 5.4) as index for chemical structures. However, this notation does not directly allow the extraction of additional information about the molecule, such as bond orders or molecular weight. 

It IS hard to find a class of compounds in which the common names of its members have influenced organic nomenclature more than carboxylic acids Not only are the common names of carboxylic acids themselves abundant and widely used but the names of many other compounds are derived from them Benzene took its name from benzoic acid and propane from propionic acid not the other way around The name butane comes from butyric acid present m rancid butter The common names of most aldehydes are derived from the common names of carboxylic acids—valeraldehyde from valeric acid for exam pie Many carboxylic acids are better known by common names than by their systematic ones and the framers of the lUPAC rules have taken a liberal view toward accepting these common names as permissible alternatives to the systematic ones Table 19 1 lists both common and systematic names for a number of important carboxylic acids... 

Systematic names formed by applying the principles of substitutive nomenclature are single words except for compounds named as acids. First one selects the parent compound, and thus the suffix, from the characteristic group listed earliest in Table 1.7. All remaining functional groups are handled as prefixes that precede, in alphabetical order, the parent name. Two examples may be helpful ... 

Because the rules for organic nomenclature determine the priority of naming different carbon chains from their relative lengths, the systematic names for type AABB polyamides depend on the relative length of the carbon chains between the amide nitrogens and the two carbonyl functions of the polymer for aUphatic nylon-Ayy, when x < the lUPAC name is poly[imino-R imino(l2y-dioxo-R )]. When x > then the name is... 

Synthesis by oxidation remains the first choice for commercial and laboratory preparation of quinones the starting material (1) provided the generic name quinone. This simple, descriptive nomenclature has been abandoned by Chemicaly hstracts, but remains widely used (2). The systematic name for (2) is 2,5-cyclohexadiene-l,4-dione. Several examples of quinone synonyms are given in Table 1. Common names are used in this article. 1,2-Benzoquinone (3,5-cydohexadiene-l,2-dione) (3) is also prepared by oxidation, often with freshly prepared silver oxide (3). Compounds related to (3) must be prepared using mild conditions because of their great sensitivity to both electrophiles and nucleophiles (4,5). 

Eor the many details of constmcting or interpreting stmctures and systematic names, the Hterature on nomenclature and indexing (6) can be consulted. Systematic nomenclature is illustrated by the Chemicaly hstracts name of the sodium iron(III) EHPG chelate sodium [[N,N -l,2-ethanediylbis[2-(2-hydroxyphenyl)glyciQatol]](4-)-N,N, 0,0, 0, 0 ]ferrate(l-) [16455-61-1], The ferrate anion (12) [20250-28-6] and the potassium salt [22569-56-8] are also Hsted ia Chemical Abstracts (7). 

Ruthless adherence to full systematic nomenclature throughout these volumes would serve little useful purpose. While it is necessary for the Chemical Abstracts indexes to avoid colloquial forms, most of our contributors seem to agree that insistence on the use of, e.g. 4(17f)-pyridinone at every point, rather than the traditional but less precise 4-pyridone , produces a pedantic effect on the English style. So old-fashioned forms like pyridone coexist here with systematic names, the choice being dictated by the individual authors of the chapters. 

Both common and systematic names of compounds are used throughout this volume, depending on which the Editor-in-Chief felt was more appropriate The Chemical Abstracts indexing name for each title compound, if it differs from the title name, is given as a subtitle Systematic Chemical Abstracts nomenclature, used in both the 9th and 10th Collective Indexes for the title compound and a selection of other compounds mentioned in the procedure, is provided in an appendix at the end of each preparation. Registry numbers, which are useful in computer searching and identification, are also provided in these appendixes. Whenever two names are concurrently in use and one name is the correct Chemical Abstracts name, that name is adopted. For example, both diethyl ether and ethyl ether are normally used. Since ethyl ether is the established Chemical Abstracts name for the 8lh Collective Index, it has been used in this volume The 9th Collective Index name is 1,1 -oxybisethane, which the Editors consider too cumbersome. 

In Table 1, drawn up by the author, of abbreviations in common use those in bold type are in the main schedule of BS 3502. In this list the names given for the materials aie the commonly used scientific names. This situation is further complicated by the adoption of a nomenclature by the International Union of Pure and Applied Chemistry for systematic names and a yet further nomenclature by the Association for Science Education which is widely used in British schools but not in industry. Some examples of these are given in Table 2. Because many rubbery materials have been referred to in this book. Tables 3 and 4 list abbreviations for these materials. 

A single alkane may have several different names a name may be a common nfflne, or it may be a systematic name developed by a well-defined set of rules. The most widely used system is lUPAC nomenclature. Table 2.6 summarizes the rules for alkanes and cycloalkanes. Table 2.7 gives the r-ules for naming alkyl groups. 

Chlorophyll a, the green photosynthesis pigment, is the prototype of the chlorin (2,3-dihydro-porphyrin) class of products. It was first isolated by Willstatter1 at the turn of the century. The common structural unit in this class is the chlorin framework named after chlorophyll. The chromophore with a partially saturated pyrrole ring, which is formally derived from the completely unsaturated porphyrin, is less symmetric than the latter and systematically named according to IUPAC nomenclature as 2,3-dihydroporphyrin. 

The bacterioehlorin structural-type is formally derived from porphyrin by saturation of two peripheral C —C double bonds in oppposite pyrrole rings and therefore systematically named according to IUPAC nomenclature as 7,8,17,18-tetrahydroporphyrin. 

Part I contains entries referring to the names of compounds according to the Chemical Abstracts Systematic Nomenclature (see Index Guide, Chemical Abstracts vol 76, 1972) The systematic name is followed by Chemical Abstracts Registry Number m brackets (see Chemical Abstracts Registry Handbook 1965-71 and Supplements) and page number... 

Common names of the compounds arc used throughout this volume. Preparations appear in the alphabetical order of common names of the compound or names of the synthetic procedures. The Chemical Abstracts indexing name for each title compound, if it differs from the common name, is given as a subtitle. Because of the major shift to new systematic nomenclature adopted by Chemical Abstracts in 1972, many common names used in the text are immediately followed by the bracketed, new names. Whenever two names are concurrently in use, the correct Chemical Abstracts name is adopted. The prefix n- is deleted from w-alkanes and w-alkyls. In the case of amines, both the common and systematic names are used, depending on which one the Editor-in-Chief feels is more appropriate. All reported dimensions are now expressed in Systeme International units. 

The index consists of two parts. Part I contains entries referring to the conventional names of compounds as they appear in the preparations of this volume followed by the systematic names in brackets, if the nomenclature differs The bracketed names conform to the systematic nomenclature adopted by the Chemical Abstracts Service starting with Chemical Abstracts Volume 76 (1972) Part II of the index contains entries of the subjects of this volume with compound names in a reversed order of Part I... 

Many compounds were given informal, common names before their compositions were known. Common names include water, salt, sugar, ammonia, and quartz. A systematic name, on the other hand, reveals which dements are present and, in some cases, the arrangement of atoms. The systemic naming of compounds, which is called chemical nomenclature, follows the simple rules described in this section. 

The aim of chemical nomenclature is to be simple but unambiguous. A systematic name specifies the elements present in the molecule and the numbers of atoms of each element. 

Like poly(ethylene), there are formal problems with the nomenclature of this polymer, since its lUPAC name, poly(propene), is also rarely if ever used hy polymer chemists. Since, in practice, no ambiguity is associated with the non-systematic name, this is the one that is generally used, as it will he throughout this hook. 

Part II consists entirely of systematic names of specific compounds according to Chemical Abstracts nomenclature (see the Index Guide in Chemical Abstracts, Volume 76, 1972). Each compound is listed under the parent name as it would appear in Chemical Abstracts, and each entry from Volumes 56 through 59 is followed by the registry number in brackets. Entries from Volumes 58 and 59 are, for the most part, taken from the appendices which follow the procedures. When the Chemical Abstracts name differs in Collective Indices 8 and 9, both names have been included. Some compounds in the appendices of this volume have been omitted from the index in accord with the guidelines given for Part I. 

A major part in the language of chemistry is in learning the names of the chemicals (nomenclature). Many chemicals, particularly the more common ones, are known by several different names. For example, the chemical CH3CH2OH has the systematic name ethanol. The publication Chemical Abstracts (American Chemical Society) also uses the name ethanol. The historical or common name is ethyl alcohol or grain alcohol. A nickname for it is just alcohol, and there are various tradenames, depending on the manufacturer. For example, the Fastman Company sells it under the name of Tecsol . Fven trained chemists have trouble with nomenclature, which makes the use of and need for written chemical formulae common among chemists. 

Some of the rigidly systematic names selected by the Association for Science Education for their nomenclature list in 1985 from the IUPAC possibilities, and some of the systematic indexing names used by Chemical Abstracts since 1972, are given as synonyms in the Index of Chemical Names (Appendix 4). This should assist those coming into industry and research with a command of those nomenclature systems but who may be unfamiliar with the current variety of names used for chemicals. The inclusion where possible of the CAS Registry Number for each title compound should now simplify the clarification of any chemical name or synonym problems, by reference to the Registry Handbook or other CAS source. 

According to the IUPAC-IUB Enzyme Nomenclature,11 pectinesterase belongs to the carboxyl ester hydrolases (EC 3.1.1.11) and has the systematic name pectin pectyl-hydrolase. The literature also contains the expressions pectin methylesterase, pectin demethoxylase, and pectin methoxylase for the same enzyme. The old name pectase,... 

All enzymes already mentioned, except oligo-D-galactosiduronate hydrolase, are included in the Enzyme Nomenclature of the IUPAC-IUB Enzyme Commission,11 and their code numbers and suitably modified, systematic names are used herein. 

The index lists the names of compounds in two forms. The first is the name used commonly in procedures. The second is the systematic name according to Chemical Abstracts nomenclature. Both are usually accompanied by registry numbers in parentheses. Also included are general terms for classes of compounds, types of reactions, special apparatus, and unfamiliar methods. 

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