1: 51 percent / POCl3, pyridine / 1.) 0 deg C, 15 min, 2.) 60-70 deg C, 2.5 h 2: benzene / 0.25 h / Irradiation; other solvents, var. conditions of irradiation, var. conc. of reactant 3: 100 percent / n-BuLi / tetrahydrofuran; hexane / 0.08 h View Scheme