Question

Give IUPAC names of the following compound:

Options

• 1-Ethoxy-6, 6-dimethylcyclohexane

• 1-Ethoxy-2, 2-dimethylcyclohexane

• 6-Ethoxy-6, 6-dimethylcyclohexane

• 2-Ethoxy-1, 1-dimethylcyclohexane

Answer 1

2-Ethoxy-1, 1-dimethylcyclohexane

Explanation:

Lowest set of locants: The lowest set of locants is defined as the set that, when compared term by term with other locant sets, each cited in order of increasing value, has the lowest term at the first point of difference.

With regard to numbering of locants, simple prefixes (simple substituent groups consisting of just one part that describes an atom, or group of atoms as a unit, for example, methyl and ethoxy) are considered together with equal seniority:

Therefore, the given compound is named as 2-Ethoxy-1, 1-dimethylcyclohexane rather than 1-Ethoxy-2, 2-dimethylcyclohexane since the locant set ‘1, 1, 2’ is lower than ‘1, 2, 2’.