9-({(4S,7R)-14-[(3,3-Dimethyloxiran-2-yl)methoxy]-5,5-dimethylspiro[1,3-dioxolane-2,2'-furano[3,2-g]chromene]-4-yl}methoxy)furano[3,2-g]chromen-2-one AIDS-104943 AIDS104943 Fesumtuorin D