反应详情

N-α-[4-(2-methylpropyl)-2-oxo-3-azetidinyl]-N-ε-3°-butoxycarbonyl-D,L-lysine benzyl ester can be prepared from trans-3-amino-4-(2-methylpropyl)-2-azetidinone (Example 78) and benzyl ε-3°-butoxy carbonylamino-2-oxohexanoate. The benzyl group can be removed by hydrogenation and the product coupled with L-proline benzyl ester. The product, N-α-[4-(2-methylpropyl)-2-oxo-3-azetidinyl]-N-ε-3°-butoxycarbonyl-D,L-lysyl-L-proline benzyl ester, can then be debenzylated with hydrogen and the β-lactam hydrolyzed with dilute base to obtain N-α-(2-amino-1-carboxy-4-methylpentyl)-N-ε-3°-butoxycarbonyl-D,L-lysyl-L-proline. After benzoylation with benzoyl chloride in organic solvent, the t-Boc protecting group can be removed with trifluoroacetic acid so that one can obtain N-α-(2-benzamido-1-carboxy-4-methylpentyl)-D,L-lysyl-L-proline.

1. customThe benzyl group can be removed by hydrogenation
2. additionwith dilute base