Question

A = Br₂, B = KOH, C = NaNH₂ Which heterocyclic ring is fused to a steroidal nucleus in Danazol?

• A. Thaizole
• B. Isoxazole
• C. Imidazole
• D. Pyrazole

Answer 1

The Correct Option is B

The question is asking about the heterocyclic ring that is fused to a steroidal nucleus in Danazol. Danazol is a synthetic steroid that is composed of several structural features, including a heterocyclic ring that plays a crucial role in its biological activity.

Let's examine each of the options given:

1. Thaizole: Thiazoles are five-membered heterocycles containing both sulfur and nitrogen. This is not the structure that is part of Danazol.
2. Isoxazole: Isoxazoles are five-membered heterocycles consisting of three carbon atoms, one oxygen, and one nitrogen atom in the ring. This ring system is indeed present in Danazol, fused to its steroidal nucleus.
3. Imidazole: Imidazoles contain a five-membered ring structure with two nitrogen atoms at non-adjacent positions. This structure is not part of Danazol.
4. Pyrazole: Pyrazoles are five-membered rings with two adjacent nitrogen atoms. This is not the heterocyclic structure present in Danazol.

The correct answer is Isoxazole, as it is the heterocyclic ring fused to the steroidal structure in Danazol.

To conclude, Danazol's chemical structure includes an isoxazole ring fused with the steroid skeleton, which is vital for its therapeutic effects.