Triphenylphosphine → ((3S,6S)-6-azido-2-oxo-azepan-3-yl)-carbamic acid tert-butyl ester

Participants

Reaction Steps

To a stirred solution of ((3S,6R)-6-hydroxy-2-oxo-azepan-3-yl)carbamic acid tert-butyl ester (3 g, 12.3 mmol example 1 f) and triphenylphosphine (3.75 g, 14.1 mmol) in THF (200 mL) at 0° C. is added diethyl azodicarboxylate (2.2 mL, 13.5 mmol) at a rate to maintain a temperature <5° C. followed immediately by addition of diphenylphosphoryl azide (2.9 mL, 13.5 mmol). The reaction is stirred for 60 h at room temperature in the dark, the solvent is removed under vacuum and the residue chromatographed on silica (hexane to ether gradient) to give 2.33 g (70%) of ((3S,6S)-6-azido-2-oxo-azepan-3-yl)-carbamic acid tert-butyl ester as a solid. MS (ESI) 270 (M+H)+

Provenance & Evidence