4-Phenylnaphtho[2,3-c]furan-1(3H)-one, 9-Phenylnaphtho[2,3-c]furan-1(3H)-one and 3a,4-Dihydro-9-phenylnaphtho[2,3-c]furan-1(3H)-one Crystal Structures

The crystal structures are reported for two unsubstituted arylnaphthalene lactones, 4-phenylnaphtho[2,3-c]furan-1(3H)-one (2), 9-phenylnaphtho[2,3-c]furan-1(3H)-one (3) and a non-aromatic dihydro arylnaphthene lactone, 3a,4-dihydro-9-phenylnaphtho[2,3-c]furan-1(3H)-one (5). There are only minor differences in the geometrical parameters of these structures. However, in certain cases, both isomers of arylnaphthalene lactones (termed Type I and Type II) were found in the same asymmetric unit cell.