Ring-Opening Hydrofluorination of 2,3- and 3,4-Epoxy Amines by HBF4·OEt2: Application to the Asymmetric Synthesis of (S,S)-3-Deoxy-3-fluorosafingol

Treatment of a range of 2,3- and 3,4-epoxy amines with HBF4·OEt2 at room temperature results in fast and efficient SN2-type ring-opening hydrofluorination to give stereodefined amino fluorohydrins. Operational simplicity, scalability, and short reaction time at ambient temperature are notable features of this method. The utility of this methodology is exemplified in a concise asymmetric synthesis of (S,S)-3-deoxy-3-fluorosafingol.