1: 34 percent / phosphorus trichloride / CHCl3 / 1.5 h / Heating 2: methanol; dioxane / Irradiation 3: NaOMe / methanol / 8 h / Ambient temperature 4: 96 percent / dioxane; H2O / 2 h / Heating View Scheme

phosphorus trichoride in chloroform 1.5 h; Heating;