1.1: BuLi / hexane; tetrahydrofuran / 1 h / 20 °C 1.2: 69.3 percent / tetrahydrofuran / 0.5 h / 20 °C 2.1: 75 percent / BBr3 / CH2Cl2 / 1 h / 20 °C 3.1: 88.5 percent / 10 percent NaOH / ethanol / 6 h / Heating View Scheme

1.1: BuLi / tetrahydrofuran / 1 h / 20 °C 1.2: 76.4 percent / tetrahydrofuran / 0.5 h / 0 °C 2.1: 66.9 percent / BBr3 / CH2Cl2 / 0.25 h / 20 °C 3.1: 92.9 percent / 10 percent NaOH / ethanol / 2 h / Heating View Scheme

1.1: BuLi / hexane; tetrahydrofuran / 1 h / 20 °C 1.2: 66.7 percent / tetrahydrofuran / 0.5 h / 20 °C 2.1: 97.1 percent / BBr3 / CH2Cl2 / 1 h / 20 °C 3.1: 86.5 percent / 10 percent NaOH / ethanol / 6 h / Heating View Scheme

Multi-step reaction with 4 steps 1: potassium t-butoxide / 1.) THF-HMPA, -60 deg C, 30 min; 2.) -20 deg C 5 min, rt overnight2: 95 percent / p-toluenesulfonic acid / methanol / 2 h / Ambient temperature3: hydrogen / Pt-C / ethyl acetate4: 1.) DMSO; 2.) oxalyl chloride, triethylamine / 1.) CH2Cl2, -78 deg C, 5 min; 2.) CH2Cl, -78 deg C 5 min, rt  

Multi-step reaction with 3 steps 1: 95 percent / p-toluenesulfonic acid / methanol / 2 h / Ambient temperature2: hydrogen / Pt-C / ethyl acetate3: 1.) DMSO; 2.) oxalyl chloride, triethylamine / 1.) CH2Cl2, -78 deg C, 5 min; 2.) CH2Cl, -78 deg C 5 min, rt