InChI=1S/C15H18O4/c1-7(2)13-12(16)10-5-4-9-6-8(3)18-15(17)11(9)14(10)19-13/h4-5,7-8,13,15,17H,6H2,1-3H3/t8-,13?,15+/m0/s1