1: pyridinium p-toluenesulfonate / CHCl3 / Ambient temperature 2: LDA / hexamethylphosphoric acid triamide; tetrahydrofuran / -78 deg C, RT 3: p-TsOH / methanol / Ambient temperature 4: 34 percent / 4 CuCl2/ 6 CuO / acetone; H2O / Heating View Scheme

Multi-step reaction with 3 steps 1: pyridinium p-toluenesulfonate / CHCl3 / Ambient temperature2: LDA / hexamethylphosphoric acid triamide; tetrahydrofuran / -78 deg C, RT3: p-TsOH / methanol / Ambient temperature