['O=CO', 'CCc1noc([C@@H]2CC=CCC2)n1', 'CC', 'O=C(O)[C@H]1CC=CC[C@H]1c1ncno1', 'CCc1ncon1', 'O=C(O)[C@H]1CC=CCC1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is C1=CC[C@@H](c2ncno2)CC1.