Lithium hydroxide, monohydrate → N-((Phenylmethoxy)carbonyl)-L-leucyl-L-leucine

Participants

Reaction Steps

To a stirred solution of N-Cbz-L-Leu-L-Leu-OCH3 (6.0 g, 14.6 mmol) in MeOH/H2O (3:1) (60 mL) at R. T. was added lithium hydroxide monohydrate (LiOH.H2O) (1.0 g, 43.9 mmol) and hydrogen peroxide H2O2 (30% weight in H2O) (4.5 mL, 43.9 mmol). The reaction mixture was stirred for 3.5 h and then quenched with 10% HCl. The resulting mixture was extracted with EA (3×20 mL). The combined organic extracts were washed with sat. NaCl (2×10 mL), dried (MgSO4) and concentrated in vacuo to afford N-Cbz-L-Leu-L-Leu-OH as a white solid (5.0 g, 90.5%): 1H NMR (CDCl3, 300 MHz) δ0.89-0.92 (t, 12 H, J=3.0 Hz), 1.48-1.71 (m, 6 H), 4.11-4.13 (m, 1 H), 4.55-4.62 (m, 1 H), 5.09 (s, 2 H), 5.64 (d, 1 H, J=9.0 Hz), 6.83 (d, 1 H, J=9.0 Hz), 7.33-7.40 (m, 5 H) ppm.

Provenance & Evidence