InChI=1S/C15H20O4/c1-9-4-3-5-10(2)7-13-14(12(17)6-9)11(8-16)15(18)19-13/h4,7,12-13,16-17H,3,5-6,8H2,1-2H3/b9-4+,10-7+/t12-,13+/m0/s1