Methanol → 3-Amino-N-((phenylmethoxy)carbonyl)-L-alanine methyl ester

Participants

Reaction Conditions

Reaction Steps

Dissolve Nα-(carbobenzyloxy)-β-(amino)-L-alanine (47.6 g, 0.2 mol) in methanol (500 mL) and treat with concentrated sulfuric acid (0.5 mL). Heat to 60° C. for 16 hours, cool and reduce the solvent by 50% in vacuo. Dilute with ethyl ether (500 mL), wash with saturated sodium hydrogen carbonate, then brine. Dry (MgSO4) and evaporate the solvent in vacuo to give Nα-(carbobenzyloxy)-β-(amino)-L-alanine, methyl ester. Dissolve Nα-(carbobenzyloxy)-β-(amino)-L-alanine, methyl ester (15.9 g, 63 mmol) in methylene chloride/cyclohexane (1:1, 600 mL). Add allyl trichloroacetimidate (26 g, 128 mmol) and trifluoromethanesulfonic acid (5 mL), 56.6 mmol). Stir at room temperature under a nitrogen atmosphere for 5 hours and dilute with methylene chloride. Wash with saturated aqueous sodium hydrogen carbonate, water, dry (MgSO4) and evaporate the solvent in vacuo. Purify by silica gel chromatography to give Nα-(carbobenzyloxyl)-β-(allylamino)-L-alanine, methyl ester.

Provenance & Evidence