['C[SH](=O)=O', 'O=S(=O)(C1COC1)N1CCNc2ccccc2C1', 'O=[SH](=O)C1COC1', 'CS(=O)(=O)N1CCNCc2ccccc21']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=S(=O)(C1COC1)N1CCNc2ccccc2C1.