1.1: triphenylphosphine / acetonitrile / 1 h / Inert atmosphere; Reflux 1.2: 9 h / 20 °C / Inert atmosphere; Reflux 2.1: palladium 10 on activated carbon; hydrogen / ethyl acetate / 1 h / 20 °C / 6000.6 Torr 3.1: chromium(VI) oxide; acetic acid / dichloromethane / 42 h / 20 °C / Inert atmosphere View Scheme