oxalyl dichloride; dimethyl sulfoxide; triethylamine in dichloromethane T=-78 - 20°C; Swern oxidation;

1: 99 percent / toluene / Heating 2: DIBAL-H / diethyl ether; hexane / 1 h / 0 °C 3: 9.9 g / (COCl)2; DMSO; Et3N / CH2Cl2 / -78 - 20 °C 4: 92 percent / toluene / Heating 5: 97 percent / DIBAL-H / diethyl ether; hexane / 1 h / 20 °C 6: 57 percent / (COCl)2; DMSO; Et3N / CH2Cl2 / -78 - 20 °C View Scheme

1: 94 percent / (COCl)2; DMSO; Et3N / CH2Cl2 / -78 - 20 °C 2: 99 percent / toluene / Heating 3: DIBAL-H / diethyl ether; hexane / 1 h / 0 °C 4: 9.9 g / (COCl)2; DMSO; Et3N / CH2Cl2 / -78 - 20 °C 5: 92 percent / toluene / Heating 6: 97 percent / DIBAL-H / diethyl ether; hexane / 1 h / 20 °C 7: 57 percent / (COCl)2; DMSO; Et3N / CH2Cl2 / -78 - 20 °C View Scheme

1: DIBAL-H / diethyl ether; hexane / 1 h / 0 °C 2: 9.9 g / (COCl)2; DMSO; Et3N / CH2Cl2 / -78 - 20 °C 3: 92 percent / toluene / Heating 4: 97 percent / DIBAL-H / diethyl ether; hexane / 1 h / 20 °C 5: 57 percent / (COCl)2; DMSO; Et3N / CH2Cl2 / -78 - 20 °C View Scheme

1: 92 percent / toluene / Heating 2: 97 percent / DIBAL-H / diethyl ether; hexane / 1 h / 20 °C 3: 57 percent / (COCl)2; DMSO; Et3N / CH2Cl2 / -78 - 20 °C View Scheme

1: 9.9 g / (COCl)2; DMSO; Et3N / CH2Cl2 / -78 - 20 °C 2: 92 percent / toluene / Heating 3: 97 percent / DIBAL-H / diethyl ether; hexane / 1 h / 20 °C 4: 57 percent / (COCl)2; DMSO; Et3N / CH2Cl2 / -78 - 20 °C View Scheme

1: 95 percent / DIBAL-H / diethyl ether; hexane / 1 h / 0 °C 2: 94 percent / (COCl)2; DMSO; Et3N / CH2Cl2 / -78 - 20 °C 3: 99 percent / toluene / Heating 4: DIBAL-H / diethyl ether; hexane / 1 h / 0 °C 5: 9.9 g / (COCl)2; DMSO; Et3N / CH2Cl2 / -78 - 20 °C 6: 92 percent / toluene / Heating 7: 97 percent / DIBAL-H / diethyl ether; hexane / 1 h / 20 °C 8: 57 percent / (COCl)2; DMSO; Et3N / CH2Cl2 / -78 - 20 °C View Scheme

1: 98 percent / toluene / Heating 2: 95 percent / DIBAL-H / diethyl ether; hexane / 1 h / 0 °C 3: 94 percent / (COCl)2; DMSO; Et3N / CH2Cl2 / -78 - 20 °C 4: 99 percent / toluene / Heating 5: DIBAL-H / diethyl ether; hexane / 1 h / 0 °C 6: 9.9 g / (COCl)2; DMSO; Et3N / CH2Cl2 / -78 - 20 °C 7: 92 percent / toluene / Heating 8: 97 percent / DIBAL-H / diethyl ether; hexane / 1 h / 20 °C 9: 57 percent / (COCl)2; DMSO; Et3N / CH2Cl2 / -78 - 20 °C View Scheme

1: 97 percent / DIBAL-H / diethyl ether; hexane / 1 h / 20 °C 2: 57 percent / (COCl)2; DMSO; Et3N / CH2Cl2 / -78 - 20 °C View Scheme