Question: 86: The correct IUPAC name of the following compound is
(1) 1-bromo-4-methyl-5-chlorohexan-3-ol
(2) 6-bromo-4-methyl-2-chlorohexan-4-ol
(3) 1-bromo-5-chloro-4-methylhexan-3-ol
(4) 6-bromo-2-chloro-4-methythexan-4-ol
Answer: Option (3)
Explanation:
The longest carbon chain containing the functional group \mathrm{OH}
consists of six carbon atoms, so the parent hydrocarbon is hexane.
According to IUPAC rules, the chain is numbered from the end nearest to the principal functional group, which is the alcohol group \mathrm{-OH}.
On numbering from the appropriate end, the \mathrm{OH} group is located at carbon number 3, hence the suffix is hexan-3-ol.
After numbering, the substituents are identified. A bromo group is present at carbon number 1, a chloro group is present at carbon number 5,
and a methyl group is present at carbon number 4.
The substituents are written in alphabetical order: bromo, chloro, and methyl,
along with their respective positions.
Therefore, the correct IUPAC name of the compound is 1-bromo-5-chloro-4-methylhexan-3-ol.