COC(=O)C1(C(=O)OC)CC(=O)c2cc3c(cc2-c2c(cc(OC)c(OC)c2OC)C1)OCO3
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?