Reaction #985322

Reaction equation

3-[2-(2-carbazol-9-yl-2-oxo-ethyl)-pentanoylamino]-5-fluoro-4-hydroxy-pentanoic acid tert-butyl ester

1,1,1-triacetoxy-1,1-dihydro-1,2-benziodoxol-3 (1H)-one

→

sub-title compound

3-[2-(2-Carbazol-9-yl-2-oxo-ethyl)-pentanoylamino]-5-fluoro-4-oxo-pentanoic acid tert-butyl ester

Solvents

DCM

DCM

Conditions

Workup

1. 1
   Washwashed sequentially with saturated aqueous sodium thiosulphate, NaHCO3 solution and brine
2. 2
   DryingThe organics were dried (Na2SO4)
3. 3
   Concentrationconcentrated
4. 4
   OtherThe residue was purified by flash chromatography (25% ethyl acetate in 40/60 hexanes)

Procedure

A stirred solution of [3S/R, 4S/R, (2R)]-3-[2-(2-carbazol-9-yl-2-oxo-ethyl)-pentanoylamino]-5-fluoro-4-hydroxy-pentanoic acid tert-butyl ester (2.51 g, 5.03 mmol) in anhydrous DCM (60 ml) was treated with 1,1,1-triacetoxy-1,1-dihydro-1,2-benziodoxol-3 (1H)-one (2.35 g, 5.53 mmol) at 0° C. The resulting mixture was kept at 0° C. for 3 h, diluted with DCM, and then washed sequentially with saturated aqueous sodium thiosulphate, NaHCO3 solution and brine. The organics were dried (Na2SO4) and concentrated. The residue was purified by flash chromatography (25% ethyl acetate in 40/60 hexanes) to afford the sub-title compound as an off white solid(1.437 g, 57%): IR (solid) 1722, 1689, 1636, 1531, 1441, 1365, 1279, 1155 cm-1; 1H NMR (400 MHz, CDCl3) δ 0.85-1.50 (3H, m), 1.35-1.54 (11H, m), 1.55-1.69 (1H, m), 1.78-1.95 (1H, m), 2.67-3.28 (4H, m), 3.60-3.79 (1H, m), 4.80-5.59 (3H, m), 6.89-7.04 (1H, m), 7.33-7.54 (4H, m), 7.98-8.04 (2H, m), 8.15-8.28 (2H, m); 13C (100 MHz, CDCl3) δ 14.12, 14.40, 14.47, 14.60, 20.78, 20.84, 21.47, 28.32, 28.42, 28.48, 29.77, 33.63, 34.58, 34.91, 40.05, 43.05, 43.26, 43.29, 52.60, 53.00, 53.64, 66.90, 66.99, 82.62, 82.69, 85.53, 116.88, 116.94, 120.28, 120.31, 124.27, 127.76, 127.86, 128.69, 128.77, 128.99, 138.80, 171.21, 171.29, 172.21, 172.25, 175.53, 176.03, 203.04, 203.20, 203.30, 203.46; 19F (376 MHz, CDCl3) δ −232.12, −233.24.

Source