Multi-step reaction with 8 steps 1.1: 5 h / 100 °C / |Inert atmosphere2.1: toluene / 3 h / |Inert atmosphere; |Dean-Stark; |Reflux2.2: 5 h / |Inert atmosphere; |Dean-Stark; |Reflux3.1: sodium acetate; acetic acid; bromine / 4 h / 45 °C / |Inert atmosphere4.1: sodium azide / N,N-dimethyl-formamide / 5 h / 45 °C / |Inert atmosphere5.1: zinc; ammonium chloride / ethyl acetate; methanol / 0.5 h / 20 - 60 °C / |Inert atmosphere6.1: (2R,3S)-(-)-di-O-benzoyl tartaric acid / isopropyl alcohol / 18 h / 20 - 85 °C / |Inert atmosphere7.1: sodium tris(acetoxy)borohydride / 1,2-dichloro-ethane / 6 h / 20 °C / |Inert atmosphere8.1: N-ethyl-N,N-diisopropylamine / dichloromethane / 24 h / 20 °C