ethyl 2,2-dimethyl-3-[(2-methylpropan-2-yl)oxycarbonylamino]propanoate

Conditions: temp:64.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Two 22 L flasks were each charged with compound 54a (583 g, 2.38 mol), LiOH.H2O (204.5 g, 4.87 mol), THF (5.7 L), and water (4.75 L). The reaction mixtures were heated to 64° C. for 19 h. The mixtures were then cooled to 10° C. with an ice bath. Approximately 1 L of 6N HCl was added to each reaction mixture to bring the pH to 3-3.5. Each mixture was combined with 2.9 L of CH2Cl2, and the aqueous layers were separated. The aqueous layers were extracted with another 1.5 L portion of CH2Cl2. The combined organic layers were dried with sodium sulfate and concentrated in vacuo to give a white solid. The solid was slurried in 5 L of heptane for 1 h, filtered, and vacuum dried to give 830 g (80% yield) of compound 55 as a white solid, mp 114-116° C. Anal. Calcd for C10H19NO4: C, 55.28; H, 8.81; N, 6.45. Found: C, 55.55; H, 8.77; N, 6.56. The reaction mixtures The mixtures were then cooled to 10° C. with an ice bath the aqueous layers were separated The aqueous layers were extracted with another 1.5 L portion of CH2Cl2 The combined organic layers were dried with sodium sulfate concentrated in vacuo to give a white solid filtered vacuum dried

Conditions: temp:64.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Two 22 L flasks were each charged with compound 54a (583 g, 2.38 mol), LiOH.H2O (204.5 g, 4.87 mol), THF (5.7 L), and water (4.75 L). The reaction mixtures were heated to 64° C. for 19 h. The mixtures were then cooled to 10° C. with an ice bath. Approximately 1 L of 6N HCl was added to each reaction mixture to bring the pH to 3-3.5. Each mixture was combined with 2.9 L of CH2Cl2, and the aqueous layers were separated. The aqueous layers were extracted with another 1.5 L portion of CH2Cl2. The combined organic layers were dried with sodium sulfate and concentrated in vacuo to give a white solid. The solid was slurried in 5 L of heptane for 1 h, filtered, and vacuum dried to give 830 g (80% yield) of compound 55 as a white solid, mp 114-116° C. Anal. Calcd for C10H19NO4: C, 55.28; H, 8.81; N, 6.45. Found: C, 55.55; H, 8.77; N, 6.56. The reaction mixtures The mixtures were then cooled to 10° C. with an ice bath the aqueous layers were separated The aqueous layers were extracted with another 1.5 L portion of CH2Cl2 The combined organic layers were dried with sodium sulfate concentrated in vacuo to give a white solid filtered vacuum dried