['CCCC=O', 'CCCCCCNCCN1CCOCC1', 'CCCCCC', 'CCCC(=O)NCCN1CCOCC1', 'CCN1CCOCC1', 'CCCCCCNC(=O)CCC', 'C1COCCN1', 'CCCCCCN(CC)C(=O)CCC']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is C1COCCN1.