Question

What is IUPAC name of catechol?

• A. Benzene-1,3,5-triol
• B. Benzene-1,2-diol
• C. Benzene-1,3-diol
• D. Benzene-1,4-diol

Hint:

Use an alphabetical memory trick for the dihydroxybenzene isomers moving from ortho to meta to para: Catechol (1,2) $\rightarrow$ Resorcinol (1,3) $\rightarrow$ Hydroquinone (1,4). CRH flows outward across the ring!

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
The question asks for the standard systematic IUPAC name corresponding to the common chemical compound known as catechol.

Step 2: Key Formula or Approach:
Catechol is a dihydroxybenzene derivative. To assign its IUPAC name, we locate the relative positions of the two hydroxyl ($-\text{OH}$) functional groups on the core aromatic benzene ring frame and append the suffix "-diol".

Step 3: Detailed Explanation:
Let's look at the three common isomeric configurations of dihydroxybenzenes:

Catechol has its two hydroxyl groups located immediately adjacent to each other on the ring (the ortho position). Numbering sequentially around the ring gives positions 1 and 2, which yields

Benzene-1,2-diol.

Resorcinol features its two hydroxyl groups in a 1,3 relationship separated by a single CH node (the meta position), which yields

Benzene-1,3-diol.

Hydroquinone (or quinol) features its two hydroxyl groups on exactly opposite sides of the ring (the para position), which yields

Benzene-1,4-diol.
Thus, catechol corresponds to Benzene-1,2-diol, matching option (B).

Step 4: Final Answer:
The IUPAC name of catechol is Benzene-1,2-diol, which corresponds to option (B).