water; pyridinium p-toluenesulfonate in acetone 2 h; Heating;

1: 1.) NaH / 1.) DMF 2: 80 percent / PPTS, H2O / acetone / 2 h / Heating View Scheme

1: 2.) p-toluenesulfonic acid / 1.) benzene, reflux, 28 h, 2.) benzene, reflux, 23 h 2: 1.) NaH / 1.) DMF 3: 80 percent / PPTS, H2O / acetone / 2 h / Heating View Scheme