COC(=O)C1(C(=O)OC)C2C(=O)C3C(C21)C3(C(=O)OC(C)(C)C)C(=O)OC(C)(C)C
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?