1. Identify a five-membered ring composed of two carbons, two oxygens, and one phosphorus, labeled sequentially as C1-O2-P3-O4-C5.
2. At P3, there is a double bond to an oxygen (=O) and a single bond to a methyl group (-CH3), making it both =O and -CH3 substituted.
3. Each of the ring carbons (C1 and C5) carries two trifluoromethyl (-CF3) substituents.