Triacetoxyperiodinane → 5-Fluoro-3-{2-[(1H-imidazole-2-carbonyl)-amino]-propionylamino}-4-oxo-pentanoic acid tert-butyl ester

Participants

Reaction Steps

A solution of [3S/R, (2S)]-5-fluoro-4-hydroxy-3-{2-[(1H-imidazole-2-carbonyl)-amino]-propionylamino}-pentanoic acid tert-butyl ester (0.381 g) in dichloromethane was cooled to 0° C. before addition of 1,1,1 triacetoxy-1,1-dihydro-1,2-benziodoxol-3(1H)-one (0.476 g). The mixture was stirred at room temperature for 2 h before addition of an additional portion of 1,1,1 triacetoxy-1,1-dihydro-1,2-benziodoxol-3(1H)-one (0.05 g) and reaction mixture was then stirred for 90 min before being concentrated at reduced pressure. The residue was dissolved in ethyl acetate and washed with a 1:1 mixture of aqueous NaHSO4 and aqueous Na2S2O3. The organic layer was collected, dried (MgSO4) and concentrated. The residue was purified by flash chromatography (5% methanol in dichloromethane) to give the sub-title compound as a colourless foam (319 mg, 84%): 1H NMR 400 MHz CDCl3 1.37+1.43 (9H, 2×s), 1.54 (3H, m), 2.85 (1H, m), 3.03 (1H, m), 4.85-5.30 (4H, m), 7.18 (2H, d, J 16), 7.90 (1H, m), 7.98 (1H, m), 11.37+11.45 (1H, 2×s); 19F NMR 376 MHz CDCl3 −231.85 (t, J 48), −232.12 (t, J 48).

Provenance & Evidence