pyridinium chlorochromate in dichloromethane T=20°C;

hydrogenchloride in tetrahydrofuran T=20°C; 10 h;

1: 59 percent / KHMDS / tetrahydrofuran; toluene / -78 - 20 °C 2: aq. HCl / tetrahydrofuran / 10 h / 20 °C View Scheme

1.1: DMF; oxalyl chloride / CH2Cl2 / 3 h 2.1: Mg; CuBr*DMS / tetrahydrofuran; diethyl ether / 0.5 h 2.2: 4.14 g / tetrahydrofuran / -40 - 20 °C 3.1: 59 percent / KHMDS / tetrahydrofuran; toluene / -78 - 20 °C 4.1: aq. HCl / tetrahydrofuran / 10 h / 20 °C View Scheme

1.1: Mg; CuBr*DMS / tetrahydrofuran; diethyl ether / 0.5 h 1.2: 4.14 g / tetrahydrofuran / -40 - 20 °C 2.1: 59 percent / KHMDS / tetrahydrofuran; toluene / -78 - 20 °C 3.1: aq. HCl / tetrahydrofuran / 10 h / 20 °C View Scheme

1: 94 percent / (COCl)2; DMSO; triethylamine / tetrahydrofuran / -78 °C 2: 78 percent / tetrahydrofuran / -40 °C 3: 49 percent / tetrabutylammonium fluoride / tetrahydrofuran / 20 °C 4: 73 percent / pyridinium chlorochromate / CH2Cl2 / 20 °C View Scheme

1: 78 percent / tetrahydrofuran / -40 °C 2: 49 percent / tetrabutylammonium fluoride / tetrahydrofuran / 20 °C 3: 73 percent / pyridinium chlorochromate / CH2Cl2 / 20 °C View Scheme

1: 49 percent / tetrabutylammonium fluoride / tetrahydrofuran / 20 °C 2: 73 percent / pyridinium chlorochromate / CH2Cl2 / 20 °C View Scheme

1.1: Mg / diethyl ether / 20 °C 1.2: 58 percent / diethyl ether / 20 °C 2.1: 94 percent / (COCl)2; DMSO; triethylamine / tetrahydrofuran / -78 °C 3.1: 78 percent / tetrahydrofuran / -40 °C 4.1: 49 percent / tetrabutylammonium fluoride / tetrahydrofuran / 20 °C 5.1: 73 percent / pyridinium chlorochromate / CH2Cl2 / 20 °C View Scheme