1.1: pyridine / dichloromethane / -30 °C 2.1: sodium azide / N,N-dimethyl-formamide / 3 h / 60 °C 3.1: sodium hydroxide / methanol; water / 1 h 4.1: chloro-trimethyl-silane; sodium iodide / acetonitrile / 2 h / 20 °C 4.3: pH 9 View Scheme