['CCO', 'Cc1c(C=O)cnn1CCO', 'CC', 'Cc1c(C(=O)O)cnn1CCO', 'CCOC=O', 'Cc1ccnn1CCO', 'CCO', 'CCOC(=O)c1cn[nH]c1C']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1cn[nH]c1.