1.1: oxalyl chloride / CH2Cl2 / 2 h / Heating 2.1: n-BuLi / tetrahydrofuran; hexane / 0.5 h / -78 °C 2.2: 43 percent / tetrahydrofuran; hexane / 0.5 h / -78 °C 3.1: n-BuLi / tetrahydrofuran; hexane / 1 h / 0 °C 3.2: 84 percent / tetrahydrofuran; hexane / 0.5 h / -78 °C 4.1: O3 / methanol / 0.5 h / -10 °C 4.2: 60 percent / thiourea / methanol / 0.92 h / 0 °C 5.1: H2 / 10 percent Pd/C / methanol / 1 h 5.2: 96 percent / diethyl ether / 20 °C 6.1: 72 percent / aq. sodium chlorite; sodium dihydrogen phosphate; 2-methyl-2-butene / 2-methyl-propan-2-ol / 0.5 h / 20 °C View Scheme

1: SOCl2 2: NH3 / H2O View Scheme