1.1: 89 percent / triethylamine; 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride / CH2Cl2 / 3 h / 20 °C 2.1: 91 percent / LiAlH4 / diethyl ether / 1.5 h / 0 °C 3.1: triethylamine / 4-N,N-dimethylaminopyridine / 20 °C 4.1: tin(II) triflate; diisopropylethylamine / CH2Cl2 / Heating 4.2: Sc(OTf)3 / CH2Cl2 / 0.5 h / Heating 5.1: HBr / acetic acid / 0.5 h / 0 °C 5.2: 25 percent / NaOMe; MeOH / 1 h / 20 °C View Scheme