sulfuric acid in methanol T=20 - 50°C;

thionyl chloride T=0°C; 0.5 h; Heating / reflux;

sulfuric acid; sodium hydrogencarbonate; trimethyl orthoformate in methanol

1.1: K2CO3 / acetone 2.1: N,N-diethylaniline 3.1: aq. NaOH / ethanol 4.1: CDI / tetrahydrofuran 4.2: NH3(gas) / tetrahydrofuran 5.1: 60 percent / potassium nitrite; iodine; 18-crown-6 / pyridine / tetrahydrofuran / 20 °C / sonication 6.1: 97 percent / NaBH4; SiO2 / CHCl3; propan-2-ol / 0.5 h / 20 °C 7.1: 61 percent / hydrazine hydrate / Raney Ni / ethanol; tetrahydrofuran / 1 h / 45 °C View Scheme

lithium borohydride in tetrahydrofuran 24 h; Reflux;