Benzyl Alcohol → Benzyl Nalpha-(9-fluorenylmethoxycarbonyl)-Nepsilon-(t-butoxycarbonyl)-L-lysine

Participants

Reaction Conditions

Reaction Steps

To a mixture of Fmoc-Lys(Boc)-OH (47, 2.0 g, 4.27 mmol) and benzyl alcohol (531 μL, 5.12 mmol) in CH2Cl2 (8.5 mL) at 0° C. was added DMAP (52 mg, 0.43 mmol) and DCC (1.06 g, 5.12 mmol). The mixture was stirred for 2 h at 0° C. and 3 h at room temperature, then filtered. Solids were washed with small portions of CH2Cl2 and the combined filtrates were concentrated, redissolved in EtOAc, washed with H2O, 0.5 N aqueous HCl solution, saturated NaHCO3 solution, saturated NaCl solution, dried over Na2SO4, filtered and concentrated. The crude product was purified by flash chromatography on a Biotage™ flash chromatography system, using a gradient of 0-10% EtOAc in CH2Cl2 to furnish compound 48 (2.3 g, 96%) as a white solid. 1H NMR (400 MHz, CDCl3) δ 1.25-1.39 (m, 2H), 1.40-1.52 (m, 2H), 1.43 (s, 9H), 1.66-1.75 (m, 1H), 1.82-1.90 (m, 1H), 3.02-3.11 (m, 2H), 4.20-4.24 (m, 1H), 4.35-4.52 (m, 4H), 5.16 (d, J=12.0 Hz, 1H), 5.22 (d, J=12.0 Hz, 1H), 5.39 (bd, J=8.0 Hz, 1H), 7.29-7.42 (m, 9H), 7.60 (d, J=7.5 Hz, 2H), 7.77 (d, J=7.5 Hz, 2H).

Provenance & Evidence