['CO', 'Cc1noc(C)c1CNC(=O)CCC=O', 'COC(=O)CCC=O', 'Cc1noc(C)c1CN', 'Cc1noc(C)c1C', 'COC(=O)CCC(N)=O', 'Cc1cc(C)on1', 'CNC(=O)CCC(=O)OC']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1cnoc1.