1,1'-[butane-1,4-diylbis(oxy-4,1-phenylene)]diethanone InChI=1/C20H22O4/c1-15(21)17-5-9-19(10-6-17)23-13-3-4-14-24-20-11-7-18(8-12-20)16(2)22/h5-12H,3-4,13-14H2,1-2H ethanone, 1,1'-[1,4-butanediylbis(oxy-4,1-phenylene)]bis-