['COCCOCCN', 'N#CC1(C=O)CCCC1', 'CO', 'CCOCCNC(=O)C1(C#N)CCCC1', 'CCOC', 'N#CC1(C(=O)NCCO)CCCC1', 'COCCO', 'CCNC(=O)C1(C#N)CCCC1', 'CCOCCOC', 'N#CC1(C(N)=O)CCCC1', 'N#CC1CCCC1', 'COCCOCCNC=O']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is C1CCCC1.