Crystal structures and conformations of two Diels–Alder adduct derivatives: 1, 8-bis­(thio­phen-2-yl)-14-oxa­tetra­cyclo­[6.5.1.02, 7.09, 13]tetra­deca-2(7), 3, 5-trien-10-one and 1, 8-di­phenyl-14-oxa­tetra­cyclo[6.5.1.02, 7.09, 13] tetra­deca-2, 4, 6-trien-10-one. (February 2015)