Multi-step reaction with 5 steps 1: 69 percent / lithium aluminium hydride / tetrahydrofuran / 2 h / 0 °C2: 1.) dimethyl sulphide, N-chlorosuccinimide, 2.) triethylamine / 1.) toluene, ether, -20 deg C, 2 h, 2.) 30 min3: 63 percent / benzene / 6 h / 80 °C4: 86 percent / ethyl di-isopropylamine / CH2Cl2 / 2 h / Heating5: 70 percent / Dowex 50W X-8 / methanol / 3 h / Ambient temperature