['O=CC[C@H]1CCOC1', 'Cc1ncc(N)cn1', 'Cc1ncccn1', 'NC(=O)C[C@H]1CCOC1', 'C1CCOC1', 'CC(=O)Nc1cnc(C)nc1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=C(C[C@H]1CCOC1)Nc1cncnc1.