['CC(C)=CC=O', 'NC1CCN(C2CC2)C1', 'CC(C)=CC(N)=O', 'C1CCN(C2CC2)C1', 'C1CC1', 'CC(C)=CC(=O)NC1CCNC1', 'CCC', 'CC(=O)NC1CCN(C2CC2)C1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is C1CCN(C2CC2)C1.