1: 2.9 g / pyridine / 24 h / Ambient temperature 2: 1) lead tetraacetate, cupric acetate, pyridine / 1) benzene, 0.5 h, RT, 2) 2 h , reflux 3: 0.26 g / NaOH / ethanol / 3 h / Heating View Scheme

1: 2.9 g / pyridine / 24 h / Ambient temperature 2: 1) lead tetraacetate, cupric acetate, pyridine / 1) benzene, 0.5 h, RT, 2) 2 h , reflux 3: 0.26 g / NaOH / ethanol / 3 h / Heating 4: 0.167 g / MnO2 / petroleum ether / 3 h / Ambient temperature View Scheme