Intramolecular [4 + 4] photocycloaddition reactions of the photochromic compounds, 3,4-bis(9-anthrylmethylene)tetrahydrofuran-2,5-dione and its 5-dicyanomethylene derivative
Intramolecular [4 + 4] photocycloaddition reactions of the photochromic compounds, 3,4-bis(9-anthrylmethylene)tetrahydrofuran-2,5-dione and its 5-dicyanomethylene derivative