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/h7-8,14-16H,3,5-6,9H2,1-2,4H3/b10-8-,11-7-