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 CCC(C(=O)[O-])C1OC(C(C)C(O)C(C)C(=O)C(CC)C2OC3(C=CCC4(CCC(C)(C5CCC(O)(CC)C(C)O5)O4)O3)C(C)CC2C)C(C)CC1C .
assistant