51175-59-8

1,4,4a,8a-Tetrahydro-endo-1,4-methanonaphthalene-5,8-dione may be used in the synthesis of pentacyclo[5.4.0.0^2,6.0^3,10.0^5,9]undecane-8,11-dione (the ′cage′ compound) via the intramolecular [2+2]-photocycloaddition reaction.

1,4,4a,8a-Tetrahydro-endo-1,4-methanonaphthalene-5,8-dione can be prepared by Diels-Alder reaction of cyclopentadiene and 1,4-benzoquinone.