1: 18 percent / SOCl2 / pyridine / 1.) 0 deg C, 30 min; 2.) reflux, 20 min 2: 45 percent / KO-t-Bu / tetrahydrofuran / 1.5 h View Scheme

1: 18 percent / SOCl2 / pyridine / 1.) 0 deg C, 30 min; 2.) reflux, 20 min 2: 45 percent / KO-t-Bu / tetrahydrofuran / 1.5 h 3: 60 percent / CH2Cl2 / 2.5 h / Heating 4: 60 percent / pyridinium hydrobromide perbromide / tetrahydrofuran / 1 h View Scheme

1: 18 percent / SOCl2 / pyridine / 1.) 0 deg C, 30 min; 2.) reflux, 20 min 2: 45 percent / KO-t-Bu / tetrahydrofuran / 1.5 h 3: 60 percent / CH2Cl2 / 2.5 h / Heating View Scheme