IUPAC Nomenclature of Alkanes

The IUPAC Nomenclature of Alkanes:
(1) The name is made up of two parts . The terminal portion or the parent name - this is the name of the longest continuous carbon chain.

(2) Preceding this is/are the substituting group(s) name(s) of the side chain(s) or branch(es). Number(s), (locants), are used to indicate the point of attachment to the parent chain. These locants are listed in numerical order separated from each other by commas, and from the remainder of the name by a hyphen.

(3) The entire hydrocarbon name is written as one word.

(4) In naming branched compounds the longest continuous chain is numbered from one end to the other using Arabic numerals. The direction in numbering is chosen so as to give the lowest numbers possible to the side chains (branches). When series of locants containing the same number of terms are compared term by term, that series is "lowest" which contains the lowest number on the occasion of the first difference. This principle is applied irrespective of the nature of the substituents.

3-bromo-2,6-dimethylheptane

(5) The names for the branches, as may be surmised from the above, are derived by
prefixing the designation of the side chain to the name of the unbranched alkyl
unit possessing the longest possible chain starting from the carbon atom at the
point of attachment to the main or parent chain. The branch is numbered starting
with the carbon at the point of attachment receiving the number one.

(6) If two or more side chains of different nature are present, they are cited in alphabetical order
(a) The names of simple side chains are first alphabetized and the multiplying prefixes are then inserted. The structure defining prefixes, when separated from the name by a hyphen and underlined are also not considered. Following this, the iso term is considered. But sec- and tert- are not.

(b) The name of a complex side chain is considered to begin with the first letter of its complete name.

c) If-two-or more-side-chains-are in-equivalent positions, the one to be assigned the lower number is that cited first in the name.

(7) The presence of identical unsubstituted side chains is indicated by the use of appropriate multiplying prefix di-, tri-, tetra-, penta-, hexa-, hepta-, octa-, nona-, deca-, etc.