1: 43 percent / P2S5 / benzene / 4 h / Ambient temperature 2: 44 percent Turnov. / acetonitrile / 8 h / Ambient temperature; Irradiation View Scheme

toluene-4-sulfonic acid in dichloromethane 48 h; Ambient temperature;

1: 78 percent / p-toluenesulfonic acid monohydrate / CH2Cl2 / 48 h / Ambient temperature 2: 82 percent / 2,2'-azobisisobutyronitrile (AIBN), tri-n-butyltin hydride / tetrahydrofuran / 6.5 h / 110 °C View Scheme