Question

Give the IUPAC name of given compound:

A.2,2-Dimethyl-3-propyl-4isopropylheptane
B.4-Isopropyl- 5-t-butyl-octane
C.4-t-Butyl-5-isopropyl octane
D.2-Methyl-3-propyl-4isopropylheptane

Answer 1

To answer this question, you should recall the concept of IUPAC nomenclature of IUPAC compounds. The IUPAC system rose to the necessity for a systematic approach due to the sheer quantity of discoveries of organic compounds which made the vernacular nomenclature of organic compounds highly inconvenient. We shall identify the longest chain as the parent chain and appropriately number the functional groups attached to it.

Complete step by step solution:
A set of rules has been formulated by IUPAC for a systematic approach for the nomenclature of organic compounds which has been revised from time to time. Any IUPAC name of the given organic compound consists of three parts of the name which are: parent name, prefix and suffix.
According to the Guidelines set by IUPAC, the nomenclature of compounds must follow these steps:
1.The Longest Chain Rule
2.The Lowest Set of Locants
3.Multiple instances of the same substituent
4.The naming of different substituents
5.Correct naming of different substituents in case they are present at the same positions
6.Naming Complex Substituents
The longest chain in the compound has 8 carbons, thus, octane. The butyl group has more priority than the propyl group and thus, it will be assigned the smaller number. It has a tertiary butyl group attached at the fourth carbon and a secondary propyl group at the fifth carbon.
Using the above rules the correct IUPAC name is 4-t-Butyl-5-isopropyl octane.

Hence, the correct answer for this question is option C.

Note: These nomenclature rules are useful to name simpler basic organic molecules. However, with more complex molecules, it fails. To overcome this problem a formal nomenclature of IUPAC is preferred. The “n-” (or normal) prefix is added in case the carbon atoms in the molecule form a continuous, unbranched (linear) chain. You should also know that compounds may consist of two elements, or more. There are several compound forms, such as carbon dioxide, common salt , marble , copper (II) sulphate, and hydrogen.