1: With n-butyllithium; tri-isopropoxy-borane in tetrahydrofuran T=-80 - 20°C; Inert atmosphere; 2: With hydrogenchloride in tetrahydrofuran; water 2 h;

1.1: toluene-4-sulfonic acid / toluene / 4 h / Reflux 2.1: sodium hydride / N,N-dimethyl-formamide; mineral oil / 4 h / 65 °C / Cooling; Inert atmosphere 3.1: n-butyllithium; tri-isopropoxy-borane / tetrahydrofuran / -80 - 20 °C / Inert atmosphere 3.2: 2 h View Scheme

1: sodium tetrahydroborate / tetrahydrofuran / 1 h / 0 °C 2: palladium 10 on activated carbon; hydrogen / methanol / 20 °C View Scheme