1: 4-methyl N-t-butylbenzenesulfonamide With n-butyllithium in tetrahydrofuran T=-78 - -20°C; 4 h; Inert atmosphere; 2: tri-isopropoxy-borane in tetrahydrofuran T=-78 - 20°C; Inert atmosphere; 3: With hydrogenchloride in tetrahydrofuran; water Inert atmosphere;

1.1: dichloromethane / 8 h / 20 °C / |Cooling with ice 2.1: n-butyllithium / tetrahydrofuran / 4 h / -78 - -20 °C / |Inert atmosphere 2.2: -78 - 20 °C / |Inert atmosphere 2.3: |Inert atmosphere View Scheme