C=C(C)C(=O)O[C@@H]1C[C@@]2(C)O[C@@H]2C[C@H](O)/C(C)=C/[C@H]2OC(=O)C(=C)[C@@H]21
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?