InChI=1S/C15H22O4/c1-9-7-14-12(10(2)15(18)19-14)5-3-11(8-16)4-6-13(9)17/h4,7,10,12-14,16-17H,3,5-6,8H2,1-2H3/b9-7-,11-4+