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
To synthesis <molecule_2d>, what are the possible reactants? Write in the SMILES representation.
user
CC(C)(C)C(=O)Nc1ccccc1-c1c2nc(c(-c3ccccc3NC(=O)C(C)(C)C)c3cc(CO)c([nH]3)c(-c3ccccc3NC(=O)C(C)(C)C)c3nc(c(-c4ccccc4NC(=O)C(C)(C)C)c4ccc1[nH]4)C=C3)C=C2.O=C(O)CCCCCCCn1ccnc1
assistant