InChI=1S/C13H20O4/c1-2-3-4-5-10-9-16-13(12(10)15)7-6-11(8-14)17-13/h3-5,11-12,14-15H,2,6-9H2,1H3/b4-3+,10-5-/t11-,12+,13-/m1/s1