potassium carbonate in methanol 3 h;

1.1: 95 percent / DMAP; pyridine / CH2Cl2 / 1 h 2.1: tert-butyllithium / tetrahydrofuran; pentane / 0.5 h / -78 °C 2.2: ZnCl2 / tetrahydrofuran; pentane / -78 - 20 °C 2.3: 91 percent / Pd(PPh3)4 / tetrahydrofuran; pentane / -20 - 5 °C 3.1: 99 percent / K2CO3 / methanol / 3 h View Scheme

1.1: tert-butyllithium / tetrahydrofuran; pentane / 0.5 h / -78 °C 1.2: ZnCl2 / tetrahydrofuran; pentane / -78 - 20 °C 1.3: 91 percent / Pd(PPh3)4 / tetrahydrofuran; pentane / -20 - 5 °C 2.1: 99 percent / K2CO3 / methanol / 3 h View Scheme

1.1: catecholborane / 12 h / 74 °C 1.2: 70 percent / I2; NaOH / diethyl ether; H2O / 1 h / 0 °C 2.1: 100 percent / tetrabutylammonium fluoride / tetrahydrofuran / 1 h / cooling 3.1: 95 percent / DMAP; pyridine / CH2Cl2 / 1 h 4.1: tert-butyllithium / tetrahydrofuran; pentane / 0.5 h / -78 °C 4.2: ZnCl2 / tetrahydrofuran; pentane / -78 - 20 °C 4.3: 91 percent / Pd(PPh3)4 / tetrahydrofuran; pentane / -20 - 5 °C 5.1: 99 percent / K2CO3 / methanol / 3 h View Scheme

1.1: 100 percent / tetrabutylammonium fluoride / tetrahydrofuran / 1 h / cooling 2.1: 95 percent / DMAP; pyridine / CH2Cl2 / 1 h 3.1: tert-butyllithium / tetrahydrofuran; pentane / 0.5 h / -78 °C 3.2: ZnCl2 / tetrahydrofuran; pentane / -78 - 20 °C 3.3: 91 percent / Pd(PPh3)4 / tetrahydrofuran; pentane / -20 - 5 °C 4.1: 99 percent / K2CO3 / methanol / 3 h View Scheme

1.1: 99 percent / K2CO3 / methanol / 6.5 h 2.1: catecholborane / 12 h / 74 °C 2.2: 70 percent / I2; NaOH / diethyl ether; H2O / 1 h / 0 °C 3.1: 100 percent / tetrabutylammonium fluoride / tetrahydrofuran / 1 h / cooling 4.1: 95 percent / DMAP; pyridine / CH2Cl2 / 1 h 5.1: tert-butyllithium / tetrahydrofuran; pentane / 0.5 h / -78 °C 5.2: ZnCl2 / tetrahydrofuran; pentane / -78 - 20 °C 5.3: 91 percent / Pd(PPh3)4 / tetrahydrofuran; pentane / -20 - 5 °C 6.1: 99 percent / K2CO3 / methanol / 3 h View Scheme

1.1: 85 percent / oxalyl chloride; DMSO; Et3N / CH2Cl2 / -78 - 20 °C 2.1: n-BuLi / tetrahydrofuran; hexane / 1 h / -78 °C 2.2: 57 percent / HMPA / tetrahydrofuran; hexane / 22 h / -20 - -10 °C 3.1: 100 percent / tetrabutylammonium fluoride / tetrahydrofuran / 1 h / 0 °C 4.1: 87 percent / iPr2NEt; SO3*pyridine / CH2Cl2; dimethylsulfoxide / 2 h / 20 °C View Scheme

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

1.1: 85 percent / oxalyl chloride; DMSO; Et3N / CH2Cl2 / -78 - 20 °C 2.1: n-BuLi / tetrahydrofuran; hexane / 1 h / -78 °C 2.2: 57 percent / HMPA / tetrahydrofuran; hexane / 22 h / -20 - -10 °C 3.1: 100 percent / tetrabutylammonium fluoride / tetrahydrofuran / 1 h / 0 °C 4.1: 87 percent / iPr2NEt; SO3*pyridine / CH2Cl2; dimethylsulfoxide / 2 h / 20 °C 5.1: 72 percent / LiBr; PPh3; diisopropyl azodicarboxylate / tetrahydrofuran / 3 h View Scheme