Benzyl Alcohol → (1S,3R)-1-(Boc-amino)-3-(Cbz-amino)cyclopentane

Participants

Reaction Conditions

Reaction Steps

A mixture of (1R,3S)-3-tert-butoxycarbonylamino-cyclopentanecarboxylic acid (1.0 g, 4.36 mmol), diphenylphosphoryl azide (1.41 mL, 6.54 mmol) and triethylamine (1.21 mL, 8.72 mmol) in toluene (15 mL) was heated at 90° C. for 3 hours then cooled to ambient temperature. Benzyl alcohol (2.48 mL, 23.98 mmol) and DMAP (54 mg, 0.44 mmol) were added and the resulting mixture heated at 90° C. for 16 hours. The cooled reaction mixture was concentrated under vacuum and the resulting residue was dissolved in ethyl acetate. The organic layer was washed with 10% aqueous citric acid and brine and the organic layer dried over sodium sulfate and concentrated under vacuum. The resulting residue was purified by column chromatography on silica gel (gradient: 0 to 30% ethyl acetate in cyclohexane) to afford 635 mg (43%) of ((1S,3R)-3-benzyloxycarbonylamino-cyclopentyl)-carbamic acid tert-butyl ester. 1H NMR (400 MHz, DMSO) δ: 7.36 (m, 5H), 6.84 (d, 1H), 5.00 (s, 2H), 3.78 (m, 2H), 2.14 (m, 1H), 1.76 (m, 2H), 1.53-1.43 (m, 2H), 1.37 (s, 9H), 1.32-1.20 (m, 1H).

Provenance & Evidence