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=CCOC1CC(C=C(C)C2OC(=O)C3CCCCN3C(=O)C(=O)C3(O)OC(C(OC)CC(C)CC(C)=CC(CC)C(=O)CC(O)C2C)C(OC)CC3C)CCC1O[Si](C)(C)C(C)(C)C .
assistant