1: acetic acid / 4 h / 100 °C 2: tin(ll) chloride / ethyl acetate / 10 h / 20 °C 3: hydrogen / ethyl acetate / 5 h / 760.05 Torr 4: sodium cyanoborohydride / methanol / 1 h / 20 °C / pH Ca. 3 5: 1,8-diazabicyclo[5.4.0]undec-7-ene / tetrahydrofuran; N,N-dimethyl-formamide / 2 h / |Reflux 6: water / benzene / 120 °C 7: zinc; acetic acid / water / 5 h / 20 °C 8: boron trichloride / dichloromethane / -10 - 20 °C View Scheme

Multi-step reaction with 4 steps 1: acetic acid / 4 h / 100 °C2: tin(ll) chloride / ethyl acetate / 10 h / 20 °C3: hydrogen / ethyl acetate / 5 h / 760.05 Torr4: sodium cyanoborohydride / methanol / 1 h / 20 °C / pH Ca. 3  

Multi-step reaction with 3 steps 1: acetic acid / 4 h / 100 °C2: tin(ll) chloride / ethyl acetate / 10 h / 20 °C3: hydrogen / ethyl acetate / 5 h / 760.05 Torr