1.1: 86 percent / (COCl)2; DMSO; Et3N / CH2Cl2 / 1.5 h / -78 °C 2.1: CrCl2 / dimethylformamide / 5 h / 0 °C 2.2: 310 mg / P(2-furyl)3 / Pd2(dba)3 / toluene / 4 h / 80 °C 3.1: 95 percent / HF*pyridine; pyridine / tetrahydrofuran / 12 h / 20 °C 4.1: 87 percent / aq. KOH / ethane-1,2-diol / 3 h / 120 °C 5.1: 64 percent / Et3N; 2-chloro-1-methylpyridinium iodide / acetonitrile / 5 h / Heating 6.1: aq. HCl / tetrahydrofuran / 48 h / 40 °C View Scheme