InChI=1S/C21H28O2/c1-13(22)20(2)11-9-19-18-6-4-14-12-15(23)5-7-16(14)17(18)8-10-21(19,20)3/h12,18-19H,4-11H2,1-3H3/t18-,19+,20-,21+/m1/s1