pyridinium p-toluenesulfonate in benzene 5 h; Heating;

2: p-TSA View Scheme

1: KOH / methanol / 10 h / Ambient temperature 2: 1.) Im2CO 3.) TsN3, Et3N / 1.) THF, room temp., 0.5 h; 2.) THF, room temp., 15 h; 3.) CH3CN, room temp., 2 h 3: 5percent Rh2(OAc)4 / CH2Cl2 / 1 h / 20 °C 4: NaBH4 / methanol / 1 h / -50 °C 5: Et3N / CH2Cl2 / 0.5 h / -20 °C 6: DBU / benzene / 4 h / 10 °C View Scheme