You are a chemist. Now you are given a product molecule. Please predict the the reactant molecules of the reaction.
The reaction equation has the following format:
```
reactant1.reactant2. ... .reactantN>>product
```
Your task is to predict the structure representation of the reactant molecule. We provide the SMILES of the reactants.
system
Do retrosynthesis with the product <molecule_2d> .
user
OK. The reactants may be C=CCOC(=O)OC1C(NC(=O)CC(CCCCCCCCCCC)OC(=O)CCCCCCCCCCC)C(OCC2OC(O[Si](C)(C)C(C)(C)C)C(N=[N+]=[N-])C(O)C2OCc2ccccc2)OC(COCc2ccccc2)C1OP1(=O)OCc2ccccc2CO1.CCCCCCCCCC(CC(=O)O)OCc1ccccc1 .
assistant