A simple conversion of azlactones into indenones via H3PW12O40/Al2O3 catalyzed intramolecular Friedel–Crafts reaction - Rostami, Mahboubeh; Khosropour, Ahmad R.; Mirkhani, Valiollah; Moghadam, Majid; Tangestaninejad, Shahram; Mohammadpoor-Baltork, Iraj (Tetrahedron Letters: International Organ for the Rapid Publication of Preliminary Communications in Organic Chemistry, 2011)