Question

According to IUPAC system, the compound

• A. Cyclohex-1-en-2-ol
• B. 1-Hydroxyhex-2-ene
• C. Cyclohex-1-en-3-ol
• D. Cyclohex-2-en-1-ol

Answer 1

The Correct Option is D

The compound depicted is a substituted cyclohexane. To name it according to IUPAC nomenclature, adhere to the following procedure:

1. Ascertain the principal functional group and the longest carbon chain containing it. In this instance, the hydroxyl group (-OH) is the highest priority functional group.
2. Number the carbon atoms of the ring. Begin with the carbon bearing the -OH group and proceed in the direction that assigns the lowest possible number to the double bond. The hydroxyl group takes precedence over the alkene.
3. Assign locants:
   • The hydroxyl group (-OH) is positioned at carbon 1.
   • The double bond originates at carbon 2.
4. Synthesize the name by combining the identified elements:
   • "Cyclohex" signifies the six-membered ring.
   • "en" indicates the presence of a double bond starting at position 2.
   • "ol" denotes the hydroxyl group at position 1.

Consequently, the definitive IUPAC name for the compound is Cyclohex-2-en-1-ol.

Let's disqualify the alternative options:

• Cyclohex-1-en-2-ol: This nomenclature is erroneous, as the double bond should be located at carbon 2.
• 1-Hydroxyhex-2-ene: This name implies an acyclic structure, not a cyclic one.
• Cyclohex-1-en-3-ol: The numbering for the hydroxyl group and the double bond is incorrect in this designation.

Therefore, the correct nomenclature is Cyclohex-2-en-1-ol.