You are a chemist. Now you are given a description of a molecule. Please generate a molecule that meets the description.
system
I give you a description of a molecule, and you need to return one molecule in SMILES that meets the description. The description: The molecule is a anti tumour.
user
COC(=O)C1=C(C(=O)OC)C2OCCN(C)C2=C2CCCCC21
assistant