C=C1C2CC[C@@]3(C)C(c4ccoc4)OC(=O)C[C@@]13OC1CC(=O)C(C)(C)C(C(O)C(=O)OC)[C@]12C
Hydrogen bond acceptor is the chemical compound which contains the lone electron pairs that participate in the hydrogen bond formation. This compound should contain a more electronegative atom (more electronegative than hydrogen) with lone electron pairs. Then it can attract protons from a donor. Moreover, the electronegative atoms usually involved in hydrogen bonding are oxygen, nitrogen and fluorine. How many hydrogen bond acceptors does the molecule contain?