ammonium sulfate 20 h; Heating;

5 h; Heating;

1: 60 percent / SnCl2 / CH2Cl2 / 5 h 2: 91 percent / NaOMe / methanol / 14 h / Ambient temperature 3: 1.) pyridine, 2.) aq. NaOH / 1.) RT, 1.5 h, 2.) THF, MeOH, 0 deg C, 30 min View Scheme

1: 60 percent / SnCl2 / CH2Cl2 / 5 h 2: 91 percent / NaOMe / methanol / 14 h / Ambient temperature View Scheme