CC(=O)[C@H]1CCCC1=O    mol9983    0_1
CC(=O)[C@H]1CC[CH-]C1=O    mol9983    -1_1
CC(=O)[C-]1CCCC1=O    mol9983    -1_2
[CH2-]C(=O)[C@H]1CCCC1=O    mol9983    -1_3