Benzyl chloroformate → (2S)-2-(((benzyloxy)carbonyl)amino)-3,3-dimethylbutanoic acid

Participants

Reaction Conditions

Reaction Steps

To a solution of L-tert-leucine (5.12 g, 39 mmol, 1 equiv) in 1,4-dioxane (80 mL) and 1M NaOH (39 mL, 39 mmol, 1.0 equiv) at 0° C. was added benzyl chloroformate (6.24 mL, 43.68 mmol, 1.12 equiv). The reaction mixture was stirred at 23° C. overnight, then concentrated, poured into 1M HCl (80 mL), and extracted with CH2Cl2 (2×100 mL). The organic layers were dried over Na2SO4 and concentrated to give crude CBZ-L-tert-leucine (20.7 g) as a clear oil: IR (cm-1) 3336, 1715, 1521, 1232; 1H NMR (CDCl3) δ 1.02 (s, 9H), 4.21 (d, 1H, J=9.9), 5.11 (s, 2H), 5.35 (d, 1H, J=9.0), 7.34-7.37 (m, 5H).

Provenance & Evidence