Email (record): Ethyl 1,3,10,12-tetra­phenyl-19,20-dioxa­hexa­cyclo­[10.6.1.1(3,10).0(2,11).0(4,9).0(13,18)]icosa-4(9),5,7,13(18),14,16-hexa­ene-2-carboxyl­ate