['CO', 'Cc1noc(C=O)c1NC(=O)OC(C)(C)C', 'CC(C)(C)O', 'COC(=O)c1onc(C)c1NC=O', 'CC(C)(C)OC=O', 'COC(=O)c1onc(C)c1N', 'CC(C)C', 'COC(=O)c1onc(C)c1NC(=O)O', 'CC(C)(C)OC(N)=O', 'COC(=O)c1cc(C)no1', 'COC=O', 'Cc1nocc1NC(=O)OC(C)(C)C']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1cnoc1.