Question

The correct IUPAC name of the compound is?

2-ethyl-1-chlorocyclohexanol
4-chloro-5-ethylcyclohexane
4-hydroxy-2-ethyl-1-chlorocyclohexane
4-chloro-3-ethylcyclohexanol

Answer 1

To answer this question, you must recall the rules for IUPAC nomenclature of a compound. While numbering, the functional group with the highest priority should get the smallest number. The order of preference for choice of the principal functional group is:
$- COOH > - S{O_3}H > - {(CO)_2}O > - COOR > - COX > - CON{H_2} > - CN$
$> - CHO > \rangle C = O > - OH > - SH > - N{H_2} > - OR > \rangle C = C\langle > - C \equiv C -$

Complete step by step solution:
We must follow the rules for the IUPAC nomenclature. These rules make sure that each compound has a different unique name.
First of all, we mark the longest chain, then identify the group attached to the chain. The next step involves the numbering of the group in such a way that the carbon to which the substituent group is present has the lowest number. Then we must determine the functional group with the highest property to be used as a suffix and other components are arranged alphabetically in the name of the compound.
The functional group attached to the main ring is the alcohol group and thus we start the numbering of the chain from that carbon. There are a total of six carbon atoms in the ring so the word root for the compound will be cyclohexane.
We number anti- clockwise to get the smallest number possible. At the third carbon, we have an ethyl group and a chlorine atom at the fourth carbon. The prefixes for these two substituent groups must be then written in alphabetical order.
The name of the compound can be written as 4-chloro-3-ethylcyclohexanol.

Thus, the correct answer is D.

Note:
It should be taken into note that the secondary suffix should be added to the primary suffix by dropping its terminal ‘e ‘.
In the question, the primary suffix has as -ane (for alkane) and the secondary suffix is -ol (for alcohol). Hence, the suffixes are written together as -an-ol.