InChI=1S/C15H20O4/c1-8-4-5-10-9(2)13(17)19-12(10)14(3)11(16)6-7-15(8,14)18/h8,10,12,18H,2,4-7H2,1,3H3/t8-,10+,12+,14-,15+/m0/s1