Diels-Alder reaction of cyclopentadiene with spiroepoxycyclohexadienon
es obtained by Adler oxidation of salicyl alcohols affords mainly endo
-endo adducts. Cope rearrangement of normal-electron-demand adducts an
d endo-endo inverse-electron-demand addition of 2a with ethylvinyl eth
er are also shown.