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.
The nomenclature of organic compounds.
Nowadays, three nomenclatures are often used to name the same organic substances : historical or trivial (in French it means everyday, non-original), rational (smart, expedient) and scientific or systematic scientific developed by IUPAC.
The trivial nomenclature of organic compounds arose accidentally, when one or another organic substance was discovered . The names often reflected natural sources from which the organic compound was first obtained (wine alcohol, urea, cane sugar, lactate, acetate, citrate, formic acid), methods for producing the substance (sulfuric ether), the names of the scientists who discovered this compound (Lewis acids, hydrocarbon Chichibabin, Michler's ketones). Sometimes such names were random (methane, acetone, asparagine, carbohydrates).
The rational nomenclature of organic compounds
It is based on the trivial names of the simplest substances typical for a given class of organic compounds, in the molecule of which one or more hydrogen atoms are replaced by another atom or atomic groups. For example, ethane by rational nomenclature is called methyl methane; ethyl alcohol (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, the creation of a new scientific nomenclature was required 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 today, is given a scientific name that is used by chemists around the world.
The basics of the nomenclature were approved at 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 Geneva). With the development of organic chemistry, it was improved and supplemented. At the IUPAC Congress in London (1947), modern provisions for the names of organic compounds in the form of “IUPAC Nomenclature Provisions” were developed and approved.
At IUPAC (Geneva), permanent commissions have been created; open and synthesized new organic compounds are given exact scientific names. In the former USSR, three volumes of the "IUPAC rules of nomenclature" were published (1st and 2nd volumes, 1979, 3rd volumes, 1983). In accordance with these rules, the name of the compounds consists of a verbal designation of fragments of the structure and signs showing the method of communication fragments.
Four methods for the formation of IUPAC names are proposed: 1) substitution - take one fragment as the basis of the name, and the second is considered as a hydrogen substitute, for example (C6H5) 2CH, diphenylmethane, 2) connecting, according to which the name of the compound is built from several peer molecules, for example C6H5 -C6H5-biphenyl; 3) functional-radical, in which the name is based on the name of the functional group, as well as the name of the radical, for example, , = 1 - vinyl chloride, 4) a variety of substitution nomenclature is used in the name of hydrogen organic compounds, the molecules of which include non-carboxylic atoms.
In everyday work, they most often use the principles of the radical functional and replacement methods of the IUPAC nomenclature.