CN1C2=C(C=CC=C2O)C(=O)C2=C1C1=C(OC(C)(C)C=C1)C(C1CC(C)(C)OC3=C1C1=C(C(O)=C3)C(=O)C3=C(N1C)C(OC1OC(C(O)C(O)C1O)C(O)=O)=CC(O)=C3)=C2O