InChI=1S/C13H20O5/c14-11(9-10-13(17)18)7-5-3-1-2-4-6-8-12(15)16/h2,4,6,8,11,14H,1,3,5,7,9-10H2,(H,15,16)(H,17,18)/b4-2+,8-6+