['Cc1ccc(C)o1', 'NCCNCCO', 'CCNCCO', 'Cc1ccc(CN)o1', 'NCCO', 'CCNCc1ccc(C)o1', 'CCO', 'Cc1ccc(CNCCN)o1', 'Cc1ccco1', 'CNCCNCCO']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccoc1.