['Cc1nnc(C=O)s1', 'N[C@@H]1C[C@H]1C1CCCCC1', 'Cc1nnc(C(N)=O)s1', 'C1CCC(C2CC2)CC1', 'Cc1nncs1', 'O=CN[C@@H]1C[C@H]1C1CCCCC1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=C(N[C@@H]1C[C@H]1C1CCCCC1)c1nncs1.