C=C1C(=O)O[C@H]2[C@@H]1[C@H](OC(=O)/C(C)=C/C)[C@]1(C)C(=O)C=C[C@H]1[C@H](C)[C@H]2O
Hydrogen bond acceptor: The atom, ion, or molecule component of a hydrogen bond which does not supply the bridging (shared) hydrogen atom. How many hydrogen bond acceptors does the molecule have?