10,15,20,21-Tetraoxa-3-thiatricylco(15.2.1.1(sup 5,8))heneicosa-5,7,12,17,19-pentaene-9,16-dione, (E)- 2-Furoic acid, 5,5'-thiodimethylenedi-, cyclic ester with trans-2-butene-1,4-diol 71349-44-5 BRN 1691341