o-Quinonoid compounds. Part II. 1,4-Diphenyl-2-benzopyran-3-one and its iron carbonyl complexes

Abstract

1,4-Diphenyl-2-benzopyran-3-one is prepared by dehydration–rearrangement of 1,3-dihydroxy-1,3-diphenyl-indian-2-one and by dehydration of o-benzoylphenyl(phenyl)acetic acid. The reactions of the pyrone and its conversion into related o-quinonoid compounds are described. The interconvertible iron carbonyl complexes of the pyrone are prepared by reaction with dodecacarbonyltri-iron. The role of metal–ligand σ-bonding in one of the complexes is discussed.