['C[C@@H]1CC=CC[C@H]1C=O', 'Cc1ccc2c(n1)OCCN2', 'C[C@@H]1CC=CCC1', 'Cc1ccc2c(n1)OCCN2C=O']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=C([C@@H]1CC=CCC1)N1CCOc2ncccc21.