The title compound, dinaphtho[2,1-b:2',3'-d]furan-8,13-(8H,13H)-dione, C20Hi003, was prepared in low yield from the reaction of (2-chloroethoxy)ethyl 2-tetrahydropyranyl ether with (R)-l,l'-binapth-2,2'-ol. The ring system is virtually planar [the largest° deviation from the mean plane of the ring is 0.116 (4)A for atom C13] despite the O13.Abstract The title compound, C9HI2N405, adopts a distinct ring-twisted conformation defined by nearly orthogonal bridgehead torsion angles [C16---C15--C14---N19 -90. 1 (2) and C26--C25--C24--N29 -87.8 (2)°]. The antiperiplanar array [C 17---014--C 14---N 19 -15 8.0 (2)