CBSE Class 10 Answered

SIR PLEASE GIVE ME A BRIEF RULE OF NAMING OF THE COMPLEX HYDRO CARBON

LIKE

SELECTING THE CHAIN

NUMBERING THE CHAIN

GIVE ATLEAST TEN CHAIN EXAMPLE

Asked by amolshukal.2001 | 30 Dec, 2017, 08:39: PM

Expert Answer

In order to name organic compounds, you must first memorize a few basic names. These names are listed within the discussion of naming alkanes.

In general, the base part of the name reflects the number of carbons in what you have assigned to be the parent chain.

The suffix of the name reflects the type(s) of functional group(s) present on (or within) the parent chain. Other groups which are attached to the parent chain are called substituents.

Identify the longest carbon chain. This chain is called the parent chain.
Identify all of the substituents (groups appending from the parent chain).
Number the carbons of the parent chain from the end that gives the substituents the lowest numbers.
When comparing a series of numbers, the series that is the "lowest" is the one which contains the lowest number at the occasion of the first difference.
If two or more side chains are in equivalent positions, assign the lowest number to the one which will come first in the name.
If the same substituent occurs more than once, the location of each point on which the substituent occurs is given.
In addition, the number of times the substituent group occurs is indicated by a prefix (di, tri, tetra, etc.).
If there are two or more different substituents they are listed in alphabetical order using the base name (ignore the prefixes).
The only prefix which is used when putting the substituents in alphabetical order is iso as in isopropyl or isobutyl.
The prefixes sec- and tert- are not used in determining alphabetical order except when compared with each other.
If chains of equal length are competing for selection as the parent chain, then the choice goes in series to:
a) the chain which has the greatest number of side chains.
b) the chain whose substituents have the lowest- numbers.
c) the chain having the greatest number of carbon atoms in the smaller side chain.
d)the chain having the least branched side chains.
A cyclic (ring) hydrocarbon is designated by the prefix cyclo- which appears directly in front of the base name.

In summary, the name of the compound is written out with the substituents in alphabetical order followed by the base name (derived from the number of carbons in the parent chain).

Commas are used between numbers and dashes are used between letters and numbers. There are no spaces in the name.

The correct structure should be as follows:

The rules for the naming of the compound are as follows:

Branched-chain alkanes

! Identify the longest chain of carbon atoms; this “parent chain” provides the root name.

(When there are two or more parent chains of identical length, choose the parent chain with the greater number of substituents. )

Here, The longest chain is having 7 carbon atoms but does not have any functional group in the chain.

Thus, we will choose the carbon chain having the substituent/functional group.

! Identify and name the substituent(s).

Thus, the name of the given compound is: 2-propyl pentane-1-ol

Here are some examples: