1.1: borane-THF / tetrahydrofuran / 0 - 20 °C / Inert atmosphere 1.2: 4.5 h / 20 - 40 °C / Inert atmosphere 2.1: oxalyl dichloride; dimethyl sulfoxide; N-ethyl-N,N-diisopropylamine / dichloromethane / 6 h / -78 - 20 °C / Inert atmosphere 3.1: lithium borohydride; (L)-TarB-NO2 / tetrahydrofuran / 0.58 h / Inert atmosphere 4.1: Zn(N3)2/bis-pyridine complex; di-isopropyl azodicarboxylate; triphenylphosphine / toluene / 4 h / Inert atmosphere 4.2: Lindlar catalyst / 20 h / Inert atmosphere 4.3: 12 h / 0 - 20 °C / Inert atmosphere View Scheme

hydrogen; palladium in acetic acid P=760 Torr; 12 h; Ambient temperature;

Hydrogenation;