1. The molecule contains a saturated five-membered ring with the following sequence (in a counterclockwise direction) : an N (position 1), a C (position 2), a C (position 3), an S (position 4), and a C (position 5), with the ring closing back at the nitrogen (position 1).
- The nitrogen (position 1) bears an ethyl group (-CH2-CH3).
- The carbon (position 2) is double-bonded to an oxygen forming a carbonyl group.
- The carbon (position 5) is double-bonded to a sulfur.
2. The carbon at position 3 carries an exocyclic double bond to an sp2 carbon (C-alpha) that is bonded to a five-membered aromatic ring (a furan) containing one oxygen and four carbons. In the furan ring, the ring oxygen is adjacent to the attachment, and the other oxygen-adjacent carbon bears an iodine substituent.