['CO', 'O=c1cc[nH]c(CN2CCCC2)c1', 'C1CCNC1', 'COc1c[nH]c(C)cc1=O', 'CN1CCCC1', 'COc1c[nH]ccc1=O']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=c1cc[nH]c(CN2CCCC2)c1.