Diels–Alder additions to 1,3-dimethyldibenz[e.g.]inden-2-one
Abstract
endo-Addition of non-conjugated dienophiles is more important for 1,3-dimethyldibenz[e.g.]inden-2-one (3) than for the cyclopentadienone (1) supporting the view that steric effect associated with non-coplanar phenyl group in (1) impede endo-addition.