1.1: n-butyllithium / tetrahydrofuran; N,N,N',N',N'',N''-hexamethylphosphoric triamide; hexane / 0.17 h / -70 °C / Inert atmosphere 1.2: 5.5 h / -70 - 20 °C / Inert atmosphere 2.1: 2,4,6-trimethyl-pyridine; oxalyl dichloride / dichloromethane / -50 °C / Inert atmosphere 3.1: sodium tetrahydroborate View Scheme

1.1: n-butyllithium / tetrahydrofuran; N,N,N',N',N'',N''-hexamethylphosphoric triamide; hexane / 0.17 h / -70 °C / Inert atmosphere 1.2: 5.5 h / -70 - 20 °C / Inert atmosphere 2.1: 2,4,6-trimethyl-pyridine; oxalyl dichloride / dichloromethane / -50 °C / Inert atmosphere View Scheme

1.1: n-butyllithium / tetrahydrofuran; N,N,N',N',N'',N''-hexamethylphosphoric triamide; hexane / 0.17 h / -70 °C / Inert atmosphere 1.2: 5.5 h / -70 - 20 °C / Inert atmosphere 2.1: 2,4,6-trimethyl-pyridine; trifluoromethylsulfonic anhydride / acetonitrile / 0 °C / Inert atmosphere View Scheme

1.1: n-butyllithium / tetrahydrofuran; N,N,N',N',N'',N''-hexamethylphosphoric triamide; hexane / 0.17 h / -70 °C / Inert atmosphere 1.2: 5.5 h / -70 - 20 °C / Inert atmosphere 2.1: 2,4,6-trimethyl-pyridine; trifluoroacetic anhydride / dichloromethane / 0 - 20 °C / Inert atmosphere View Scheme