Nomenclature of organic compounds

In the chemical literature and everyday life, the names of organic bio-compounds based on various nomenclature systems are used. There is a need to get acquainted with their basic principles.

Nomenclature of organic compounds.

In our time, three nomenclatures are often used for the name of the same organic substances : historical, or trivial, rational (intelligent, expedient) and scientific, or systematic, scientific, developed by IUPAC.

The trivial nomenclature of organic compounds arose accidentally, when an organic substance was discovered . Names often reflected natural sources, from which the organic compound was first obtained (wine alcohol, urea, cane sugar, lactate, acetate, citrate, formic acids), methods for obtaining the substance (sulfuric ether), the names of scientists who discovered this compound (Lewis acids, hydrocarbon Chichibabina, Michler's ketones). Sometimes such names were accidental (methane, acetone, asparagine, carbohydrates).

Rational nomenclature of organic compounds

It is based on the trivial names of the simplest substances typical of a given class of organic compounds, in a molecule of which one or more hydrogen atoms are replaced by another atom or atomic groups. For example, ethane in the rational nomenclature is called methyl methane; Ethyl alcohol (a derivative of the simplest alcohol carbinol) - methylcarbinol; Propionic acid - methyl acetate, etc. However, for more complex biostructures this nomenclature of organic substances is unsuitable. Therefore, it was required to create a new scientific nomenclature, in which the name of the bio-compound and its structure should correspond to each other.

The scientific nomenclature of organic compounds created by IUPAC is the most accurate of the above. According to its rules, each organic substance, discovered or synthesized earlier, as well as synthesized in our days, is assigned a scientific name, which is used by chemists from all over the world.

The foundations of the nomenclature were approved on the initiative of the German organic chemist A. V. Hoffmann (1818-1892) in 1892 at the International Congress of Chemists in Geneva (this nomenclature of organic compounds was called the Geneva nomenclature). With the development of organic chemistry, it was perfected and supplemented. At the IUPAC congress in London (1947), modern provisions for the names of organic compounds were developed and approved in the form of the "Regulations of the IUPAC nomenclature".

With IUPAC (Geneva), permanent commissions have been set up, and scientific names are given to open and synthesized new organic compounds. Three volumes of the "nomenclature rules of IUPAC" were published in the former USSR (1 st and 2 nd t. 1979, 3 rd t. - 1983). In accordance with these rules, the name of the compounds consists of a verbal designation of structural fragments and signs showing the way the fragments are connected.

Four ways of forming the IUPAC names are proposed: 1) substitutionary - one fragment is taken as a basis for the name, and the second is considered as a hydrogen substituent, for example (C6H5) 2CH, - diphenylmethane, 2) connecting, according to which the name of the compound is built from several equal molecules, for example, C6H5 -C6H5-biphenyl; 3) functionally radical, where the name is based on the name of the functional group, as well as the name of the radical, for example, CH, = CHCl - vinyl chloride; 4) a variety of substitution nomenclature is used in the name of hydrogen organic compounds whose molecules contain non-carbon atoms.

In everyday work, the principles of the radical functional and substitute methods of the IUPAC nomenclature are most often used.