InChI=1S/C20H28O2/c1-6-20(4)11-9-14-13-8-7-10-19(2,3)15(13)12-16(21)17(14)18(20)22-5/h6,12,18,21H,1,7-11H2,2-5H3/t18-,20-/m0/s1