['CO', 'C[C@@H](CCC=O)[C@@H]1CC[C@@H]2[C@@H]3CC[C@@H]4C[C@H](O)CC[C@]4(C)C3=CC[C@@]21C', 'CCCCC(=O)OC', 'C[C@]12CC=C3[C@@H](CC[C@@H]4C[C@H](O)CC[C@]34C)[C@H]1CCC2']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is C1=C2C3CCCC[C@H]3CC[C@H]2[C@H]2CCCC2C1.