sodium tetrahydroborate in methanol T=0°C; Inert atmosphere;

1: Schwartz's reagent / tetrahydrofuran / 20 °C / Inert atmosphere 2: sodium tetrahydroborate / methanol / 0 °C / Inert atmosphere View Scheme

1.1: thionyl chloride; N,N-dimethyl-formamide / Inert atmosphere 2.1: tetrahydrofuran / Inert atmosphere 3.1: N,N,N',N,-tetramethylethylenediamine; sec.-butyllithium / tetrahydrofuran; cyclohexane / 3.5 h / -78 °C / Inert atmosphere 3.2: 8 h / -78 - 20 °C / Inert atmosphere 4.1: Schwartz's reagent / tetrahydrofuran / 20 °C / Inert atmosphere 5.1: sodium tetrahydroborate / methanol / 0 °C / Inert atmosphere View Scheme

1.1: tetrahydrofuran / Inert atmosphere 2.1: N,N,N',N,-tetramethylethylenediamine; sec.-butyllithium / tetrahydrofuran; cyclohexane / 3.5 h / -78 °C / Inert atmosphere 2.2: 8 h / -78 - 20 °C / Inert atmosphere 3.1: Schwartz's reagent / tetrahydrofuran / 20 °C / Inert atmosphere 4.1: sodium tetrahydroborate / methanol / 0 °C / Inert atmosphere View Scheme

1.1: N,N,N',N,-tetramethylethylenediamine; sec.-butyllithium / tetrahydrofuran; cyclohexane / 3.5 h / -78 °C / Inert atmosphere 1.2: 8 h / -78 - 20 °C / Inert atmosphere 2.1: Schwartz's reagent / tetrahydrofuran / 20 °C / Inert atmosphere 3.1: sodium tetrahydroborate / methanol / 0 °C / Inert atmosphere View Scheme