1: triphenylphosphine; diethylazodicarboxylate / tetrahydrofuran / 1.5 h / -78 - 20 °C / |Inert atmosphere 2: AD-mix-βreg;; methanesulfonamide; osmium(VIII) oxide / dichloromethane; #tert!-butyl alcohol; water / 72 h / 20 °C / |Inert atmosphere 3: pyridinium p-toluenesulfonate / toluene / 2 h / 90 °C / |Inert atmosphere 4: lithium hydroxide hydrate / methanol; tetrahydrofuran / 0.5 h / 20 °C / |Inert atmosphere 5: boron tribromide / dichloromethane / -78 - 20 °C / |Inert atmosphere View Scheme