o-Fluoranil chemistry: Diels-Alder versus hetero-Diels-Alder cycloaddition

The title quinone undergoes 4 + 2] cycloadditions in two ways, Diels-Alder on the ring and hetero-Diels-Alder by attack at the oxygens. The latter mode of reaction is strongly favored thermodynamically, but there is a kinetic bias favoring the normal Diels-Alder addition that often prevails, especially with cycloaddends that are not electron-rich.