1.1: oxalyl dichloride; dimethyl sulfoxide / dichloromethane 2.1: benzene / 70 °C 3.1: chromium dichloride / tetrahydrofuran / 0 °C 4.1: piperidine; copper(l) iodide; tetrakis(triphenylphosphine) palladium(0) / benzene / 20 °C 5.1: pyridinium p-toluenesulfonate / methanol / 0 °C 6.1: copper/silver activated zinc; water / methanol / 16 h / 40 - 45 °C 7.1: lithium hydroxide hydrate / methanol; water / 24 h / 0 °C 7.2: Saturated solution View Scheme