O=C(O)[C@]12C[C@]3(C(=O)O)C[C@@](C(=O)O)(C[C@](C(=O)O)(C1)C3=O)C2=O
The donor in a hydrogen bond is usually a strongly electronegative atom such as N, O, or F that is covalently bonded to a hydrogen bond. How many hydrogen bond donors does the molecule have?