InChI=1S/C15H20O3/c1-8-5-4-6-10-7-11-12(9(2)14(17)18-11)13(16)15(8,10)3/h7-8,11,13,16H,4-6H2,1-3H3/t8-,11+,13-,15+/m0/s1