1: With triethylamine in tetrahydrofuran T=-30°C; Substitution; 2: With lithium triethylborohydride in tetrahydrofuran T=-78°C; Reduction;

1.1: 94 percent / CH2Cl2; diethyl ether 2.1: 42 percent / Lithium bis(trimethylsilyl)amid 3.1: 72 percent / LiAlH4 / tetrahydrofuran / 2 h / 0 °C 4.1: Et3N / tetrahydrofuran / -30 °C 4.2: LiEt3BH / tetrahydrofuran / -78 °C View Scheme

1.1: 42 percent / Lithium bis(trimethylsilyl)amid 2.1: 72 percent / LiAlH4 / tetrahydrofuran / 2 h / 0 °C 3.1: Et3N / tetrahydrofuran / -30 °C 3.2: LiEt3BH / tetrahydrofuran / -78 °C View Scheme