Begin by labeling a fused bicyclic system as follows:
- The first ring (Ring A) is a benzene ring, with its carbons numbered A1 through A6.
- This ring is fused to a second ring (Ring B) across two adjacent carbons (A5 and A6). Ring B has six members in total (B1-B2-B3-B4-A6-A5), where B1 is oxygen, B4 is nitrogen, and the remaining positions are occupied by carbons. B3, bearing a hydroxyl, is double-bonded to B4.
On Ring A:
1. A2 is bonded to an imine carbon which bears a hydroxyl group (i.e., A2-C(O)=N-).
2. That nitrogen is then connected by a methylene unit (-CH2-) to a four-membered saturated ring (a cyclobutane).
3. On that cyclobutane ring, at the same linkage carbon, there is an additional methylene unit (-CH2-) to an isopropyl branching (-CH(CH3)2).
