Nomenclature Number positions

In systematic nomenclature, the position of a substituent is designated by a number. The carbonyl carbon of a carboxylic acid is always the C-1 carbon. In common nomenclature, the position of a substituent is designated by a lowercase Greek letter, and the carbonyl carbon is not given a designation. The carbon adjacent to the carbonyl carbon is the a-carbon, the carbon adjacent to the a-carbon is the jS-carbon, and so on. 

The common name for a ketone solvent involves naming the longest hydrocarbon chain that includes the carbonyl carbon atom and affixing the suffix one to the hydrocarbon name. The proper nomenclature numbering assigns the lowest number to the position of the carbonyl group and other numbers... 

The nomenclature of inorganic chemistry is based upon the assignment of numbers (positive or negative) to the atoms of the elements. These numbers, called oxidation numbers, are defined in the following way. 

Although many conventional names (e.g., cholesterol, cortisol, testosterone, etc.) are used in steroid molecules, the use of systematic names (based on lUPAC rules) is recommended. According to the nomenclature, a complete description of a steroid molecule should include the name of their parent compound (e.g., pregnane-21C, androstane-19C, or estrane-18C series) and the name, number, position, and orientation (a or jS) of all functional groups. 

In naming alkynes the usual lUPAC rules for hydrocarbons are followed and the suffix ane is replaced by yne Both acetylene and ethyne are acceptable lUPAC names for HC=CH The position of the triple bond along the chain is specified by number m a manner analogous to alkene nomenclature... 

The mathematical solution for maximum vacuum is based on Eq. (26-56), which solves the NPSH equation for this value of the fluid height. The nomenclature used contains only positive numbers for elevation, with the base point being set at the tank s discharge nozzle (analogous to the gravity-discharge case). 

Alkyne nomenclature follows the general rules for hydrocarbons discussed in Sections 3.4 and 6.3. The suffix -yne is used, and the position of the triple bond is indicated by giving the number of the first alkyne carbon in the... 

Porphyrins are formally derived from the porphin (1) nucleus by substitution of some or all peripheral positions with various side chains. In the classical system of nomenclature T, introduced by H. Fischer,Sc the peripheral /5-pyrrolic positions are numbered front 1 to 8 and the methine positions (also named meso positions) between the pyrrole rings are designated a, //, y, and 5. The rings are lettered clockwise A, B, C, and D. The classical nomenclature was in the past more and more displaced by a nomenclature which numbers all the carbon... 

---