InChI=1S/C18H26O2/c1-13(7-6-8-15(3)19)9-10-17-14(2)11-16(20)12-18(17,4)5/h6-10,16,20H,11-12H2,1-5H3/b8-6+,10-9+,13-7+/t16-/m1/s1