CC1(C)CC(=O)C(C=O)C(=O)C1    mol12562    0_1
CC1(C)[CH-]C(=O)C(C=O)C(=O)C1    mol12562    -1_1
CC1(C)CC(=O)[C-](C=O)C(=O)C1    mol12562    -1_2