(E)-3,3,6,6-Tetra­methyl-9-(2-nitro­styr­yl)-3,4,5,6,7,9-hexa­hydro-1H-xanthene-1,8(2H)-dione

In the title compound, C₂₅H₂₇NO₅, each of the cyclo­hexenone rings adopts a half-chair conformation, whereas the six-membered pyran ring adopts a flattened boat conformation, with the O and methine C atoms deviating from the plane of the other four atoms. In the crystal, weak C—H...O hydrogen bonds link mol­ecules into chains parallel to the c axis.