['CC(C)(C)NC=O', 'CCC1(C)CNC1', 'CC(C)(C)N', 'CCC1(C)CN(C=O)C1', 'CC(C)C', 'CCC1(C)CN(C(N)=O)C1', 'CC', 'CC1CN(C(=O)NC(C)(C)C)C1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is C1CNC1.