['O=C1COc2cc(O)ccc21', 'CCn1cc(C)c2ccccc21', 'CC', 'O=C1/C(=C/c2c[nH]c3ccccc23)Oc2cc(O)ccc21']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=C1/C(=C/c2c[nH]c3ccccc23)Oc2ccccc21.