InChI=1S/C17H22O4/c1-10-6-5-7-11(2)9-15-16(12(3)17(19)21-15)14(8-10)20-13(4)18/h6,9,14-16H,3,5,7-8H2,1-2,4H3/b10-6+,11-9+